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GLP-1 Receptor Agonist Use in Gastrointestinal Endoscopy: A Review of Current Evidence and Guidelines
The use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) has increased over the past several years and has become a cornerstone in both diabetes and weight loss management, particularly because of its unique combination of glucose control, weight reduction potential, and cardiac and metabolic benefits. However, increased use of these agents presents a dilemma in gastrointestinal endoscopy as it pertains to their safety and management during the periprocedural period.
highlighting gaps and future directions.
Pharmacology and Mechanisms of Action
GLP-1 RAs have several mechanisms of action that make them relevant in gastrointestinal endoscopy. These medications modulate glucose control via enhancement of glucose-dependent insulin secretion and reduction of postprandial glucagon, which promotes satiety and delays gastric emptying. This delay in gastric emptying mediated by vagal pathways has been postulated to increase gastric residuals, posing a risk for aspiration during anesthesia.1
It is important to also consider the pharmacokinetics of GLP-1 RAs, as some have shorter half-lives on the order of several hours, like exenatide, while others, like semaglutide, are dosed weekly. Additionally, common side effects of GLP-1 RAs include nausea, vomiting, bloating, and early satiety, which pose challenges for patients undergoing endoscopic procedures.
Current Guidelines
Various societies have published guidelines on the periprocedural use of GLP-1 RAs. The American Society of Anesthesiologist (ASA) in 2023 presented early recommendations to hold GLP-1 RAs either day of procedure or week prior depending on pharmacokinetics, because of the risk of delayed gastric emptying and increased potential for aspiration.2 Soon thereafter, a multi-gastroenterology society guideline was released stating more data is needed to decide if GLP-1 RAs need to be held prior to endoscopic procedures.3
In early 2024, the American Gastroenterological Association (AGA) published a rapid clinical update that advocated for a more individualized approach, particularly in light of limited overall data for GLP-1 RAs and endoscopic procedures.4 In asymptomatic patients who follow typical fasting protocols for procedures, it is generally safe to proceed with endoscopy without holding GLP-1 RAs. In symptomatic patients (nausea, abdominal distension, etc), the AGA advises additional precautions, including performing transabdominal ultrasound if feasible to assess retained gastric contents. The AGA also suggests placing a patient on a clear liquid diet the day prior to the procedure — rather than holding GLP-1 RAs — as another reasonable strategy.
The guidelines continue to evolve with newer multi-society guidelines establishing best practices. While initially in 2023 the ASA did recommend holding these medications prior to endoscopy, the initial guidance was based on expert opinion with limited evidence. Newer multi-society guidance published jointly by the ASA along with various gastroenterology societies, including the AGA in December 2024, takes a more nuanced approach.5
The newer guidelines include two main recommendations:
1. Periprocedural management of GLP-1 RAs should be a joint decision among the procedural, anesthesia, and prescribing team balancing metabolic needs vs patient risks.
- In a low-risk patient, one that is asymptomatic and on standard dosing, among other factors, the guidance states that GLP-1 RAs can be continued.
- In higher-risk patients, the original guidance of holding a day or a week prior to endoscopic procedures should be followed.
2. Periprocedural management of GLP-1 RAs should attempt to minimize the aspiration risks loosely associated with delayed gastric emptying.
- Consider a 24-hour clear liquid diet a day prior to the procedure and transabdominal ultrasound to check gastric contents.
- It is acknowledged that this guidance is based on limited evidence and will be evolving as new medications and data are released.
Recent Clinical Studies
Although there is very little data to guide clinicians, several recent studies have been published that can direct clinical decision-making as guidelines continue to be refined and updated.
A multicenter trial of approximately 800 patients undergoing upper endoscopy found a significant difference in rates of retained gastric contents between those that underwent endoscopy who did and did not follow the ASA guidance on periprocedural management of GLP-1 RAs (12.7% vs 4.4%; P < .0001). However, there were no significant differences in rates of aborted procedures or unplanned intubations.
Furthermore, a multivariable analysis was performed controlling for GLP-1 RA type and other factors, which found the likelihood of gastric retention increased by 36% for every 1% increase in hemoglobin A1c. This study suggests that a more individualized approach to holding GLP-1 RA would be applicable rather than a universal periprocedural hold.6
More recently, a single-center study of nearly 600 patients undergoing upper endoscopy showed that while there were slightly increased rates of retained gastric contents (OR 3.80; P = .003) and aborted procedures (1.3% vs 0%; P = .02), the rates of adverse anesthesia events (hypoxia, etc) were similar between the groups and no cases of pulmonary aspiration were noted.7
One single-center study of 57 patients evaluated the safety of GLP-1 RAs in those undergoing endoscopic sleeve gastrectomy. GLP-1 RAs were continued on all patients, but all adhered to a liquid only diet for at least 24 hours prior to the procedure. There were no instances of retained gastric solids, aspiration, or hypoxia. This study suggests that with a 24-hour clear liquid diet and routine NPO recommendations prior to endoscopy, it would be safe to continue GLP-1 RAs. This study provides rationale for the AGA recommendation for a clear liquid diet 24 hours prior to endoscopic procedures for those on GLP-1 RAs.8
A study looking at those who underwent emergency surgery and endoscopy with claims data of use of GLP-1 RAs found an overall incidence of postoperative respiratory complications of 3.5% for those with GLP-1 RAs fill history vs 4.0% for those without (P = .12). Approximately 800 of the 24,000 patients identified had undergone endoscopic procedures for GI bleeding or food impaction. The study overall showed that preoperative use of GLP-1 RAs in patients undergoing surgery or endoscopy, evaluated as a combined group, was not associated with an increased risk of pulmonary complications.9
Lastly, a systematic review and meta-analysis that included 15 studies that quantified gastric emptying using various methods, including gastric emptying scintigraphy and acetaminophen absorption test, found that there was a quantifiable delay in gastric emptying of about 36 minutes, compared to placebo (P < .01), in patients using GLP-1 RAs. However, compared to standard periprocedural fasting, this delay is clinically insignificant and standard fasting protocols would still be appropriate for patients on GLP-1 RAs.10
These studies taken together suggest that while GLP-1 RAs can mildly increase the likelihood of retained gastric contents, there is no statistically significant increase in the risk of aspiration or other anesthesia complications. Furthermore, while decreased gastric emptying is a known effect of GLP-1 RAs, this effect may not be clinically significant in the context of standard periprocedural fasting protocols particularly when combined with a 24-hour clear liquid diet. These findings support at a minimum a more patient-specific strategy for periprocedural management of GLP-1 RAs.
Clinical Implications
These most recent studies, as well as prior studies and guidelines by various societies lead to a dilemma among endoscopists on proper patient counseling on GLP-1 RAs use before endoscopic procedures. Clinicians must balance the metabolic benefits of GLP-1 RAs with potential endoscopic complications and risks.
Holding therapy theoretically decreases aspiration risk and pulmonary complications, though evidence remains low to support this. Holding medication, however, affects glycemic control leading to potential rebound hyperglycemia which may impact and delay plans for endoscopy. With growing indications for the use of GLP-1 RAs, a more tailored patient-centered treatment plan may be required, especially with consideration of procedure indication and comorbidities.
Currently, practice patterns at different institutions vary widely, making standardization much more difficult. Some centers have opted to follow ASA guidelines of holding these medications up to 1 week prior to procedures, while others have continued therapy with no pre-procedural adjustments. This leaves endoscopists to deal with the downstream effects of inconvenience to patients, care delays, and financial considerations if procedures are postponed related to GLP-1 RAs use.
Future Directions
Future studies are needed to make further evidence-based recommendations. Studies should focus on stratifying risks and recommendations based on procedure type (EGD, colonoscopy, etc). More widespread implementation of gastric ultrasound can assist in real-time decision-making, albeit this would require expertise and dedicated time within the pre-procedural workflow. Randomized controlled trials comparing outcomes of patients who continue GLP-1 RAs vs those who discontinue stratified by baseline risk will be instrumental for making concrete guidelines that provide clarity on periprocedural management of GLP-1 RAs.
Conclusion
The periprocedural management of GLP-1 RAs remains a controversial topic that presents unique challenges in endoscopy. Several guidelines have been released by various stakeholders including anesthesiologists, gastroenterologists, and other prescribing providers. Clinical data remains limited with no robust evidence available to suggest that gastric emptying delays caused by GLP-1 RAs prior to endoscopic procedures significantly increases risk of aspiration, pulmonary complications, or other comorbidities. Evolving multi-society guidelines will be important to establish more consistent practices with reassessment of the data as new studies emerge. A multidisciplinary, individualized patient approach may be the best strategy for managing GLP-1 RAs for patients undergoing endoscopic procedures.
Dr. Sekar and Dr. Asamoah are based in the department of gastroenterology at MedStar Georgetown University Hospital, Washington, D.C. Dr. Sekar reports no conflicts of interest in regard to this article. Dr. Asamoah serves on the Johnson & Johnson advisory board for inflammatory bowel disease–related therapies.
References
1. Halim MA et al. Glucagon-Like Peptide-1 Inhibits Prandial Gastrointestinal Motility Through Myenteric Neuronal Mechanisms in Humans. J Clin Endocrinol Metab. 2018 Feb. doi: 10.1210/jc.2017-02006.
2. American Society of Anesthesiologists. American Society of Anesthesiologists releases consensus-based guidance on preoperative use of GLP-1 receptor agonists. 2023 Jun 20. www.asahq.org/about-asa/newsroom/news-releases/2023/06/american-society-of-anesthesiologists-consensus-based-guidance-on-preoperative
3. American Gastroenterological Association. GI multi-society statement regarding GLP-1 agonists and endoscopy. 2023 Jul 25. gastro.org/news/gi-multi-society-statement-regarding-glp-1-agonists-and-endoscopy/.
4. Hashash JG et al. AGA Rapid Clinical Practice Update on the Management of Patients Taking GLP-1 Receptor Agonists Prior to Endoscopy: Communication. Clin Gastroenterol Hepatol. 2024 Apr. doi: 10.1016/j.cgh.2023.11.002.
5. Kindel TL et al; American Gastroenterological Association; American Society for Metabolic and Bariatric Surgery; American Society of Anesthesiologists; International Society of Perioperative Care of Patients with Obesity; Society of American Gastrointestinal and Endoscopic Surgeons. Multi-society Clinical Practice Guidance for the Safe Use of Glucagon-like Peptide-1 Receptor Agonists in the Perioperative Period. Clin Gastroenterol Hepatol. 2024 Oct. doi: 10.1016/j.cgh.2024.10.003.
6. Phan J et al. Glucagon-Like Peptide Receptor Agonists Use Before Endoscopy Is Associated With Low Retained Gastric Contents: A Multicenter Cross-Sectional Analysis. Am J Gastroenterol. 2025 Mar. doi: 10.14309/ajg.0000000000002969.
7. Panchal S et al. Endoscopy and Anesthesia Outcomes Associated With Glucagon-like Peptide-1 Receptor Agonist use in Patients Undergoing Outpatient Upper Endoscopy. Gastrointest Endosc. 2025 Aug. doi:10.1016/j.gie.2025.01.004.
8. Maselli DB et al. Safe Continuation of glucagon-like Peptide 1 Receptor Agonists at Endoscopy: A Case Series of 57 Adults Undergoing Endoscopic Sleeve Gastroplasty. Obes Surg. 2024 Jul. doi: 10.1007/s11695-024-07278-2.
9. Dixit AA et al. Preoperative GLP-1 Receptor Agonist Use and Risk of Postoperative Respiratory Complications. JAMA. 2024 Apr. doi: 10.1001/jama.2024.5003.
10. Hiramoto B et al. Quantified Metrics of Gastric Emptying Delay by Glucagon-Like Peptide-1 Agonists: A systematic review and meta-analysis with insights for periprocedural management. Am J Gastroenterol. 2024 Jun. doi: 10.14309/ajg.0000000000002820.
The use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) has increased over the past several years and has become a cornerstone in both diabetes and weight loss management, particularly because of its unique combination of glucose control, weight reduction potential, and cardiac and metabolic benefits. However, increased use of these agents presents a dilemma in gastrointestinal endoscopy as it pertains to their safety and management during the periprocedural period.
highlighting gaps and future directions.
Pharmacology and Mechanisms of Action
GLP-1 RAs have several mechanisms of action that make them relevant in gastrointestinal endoscopy. These medications modulate glucose control via enhancement of glucose-dependent insulin secretion and reduction of postprandial glucagon, which promotes satiety and delays gastric emptying. This delay in gastric emptying mediated by vagal pathways has been postulated to increase gastric residuals, posing a risk for aspiration during anesthesia.1
It is important to also consider the pharmacokinetics of GLP-1 RAs, as some have shorter half-lives on the order of several hours, like exenatide, while others, like semaglutide, are dosed weekly. Additionally, common side effects of GLP-1 RAs include nausea, vomiting, bloating, and early satiety, which pose challenges for patients undergoing endoscopic procedures.
Current Guidelines
Various societies have published guidelines on the periprocedural use of GLP-1 RAs. The American Society of Anesthesiologist (ASA) in 2023 presented early recommendations to hold GLP-1 RAs either day of procedure or week prior depending on pharmacokinetics, because of the risk of delayed gastric emptying and increased potential for aspiration.2 Soon thereafter, a multi-gastroenterology society guideline was released stating more data is needed to decide if GLP-1 RAs need to be held prior to endoscopic procedures.3
In early 2024, the American Gastroenterological Association (AGA) published a rapid clinical update that advocated for a more individualized approach, particularly in light of limited overall data for GLP-1 RAs and endoscopic procedures.4 In asymptomatic patients who follow typical fasting protocols for procedures, it is generally safe to proceed with endoscopy without holding GLP-1 RAs. In symptomatic patients (nausea, abdominal distension, etc), the AGA advises additional precautions, including performing transabdominal ultrasound if feasible to assess retained gastric contents. The AGA also suggests placing a patient on a clear liquid diet the day prior to the procedure — rather than holding GLP-1 RAs — as another reasonable strategy.
The guidelines continue to evolve with newer multi-society guidelines establishing best practices. While initially in 2023 the ASA did recommend holding these medications prior to endoscopy, the initial guidance was based on expert opinion with limited evidence. Newer multi-society guidance published jointly by the ASA along with various gastroenterology societies, including the AGA in December 2024, takes a more nuanced approach.5
The newer guidelines include two main recommendations:
1. Periprocedural management of GLP-1 RAs should be a joint decision among the procedural, anesthesia, and prescribing team balancing metabolic needs vs patient risks.
- In a low-risk patient, one that is asymptomatic and on standard dosing, among other factors, the guidance states that GLP-1 RAs can be continued.
- In higher-risk patients, the original guidance of holding a day or a week prior to endoscopic procedures should be followed.
2. Periprocedural management of GLP-1 RAs should attempt to minimize the aspiration risks loosely associated with delayed gastric emptying.
- Consider a 24-hour clear liquid diet a day prior to the procedure and transabdominal ultrasound to check gastric contents.
- It is acknowledged that this guidance is based on limited evidence and will be evolving as new medications and data are released.
Recent Clinical Studies
Although there is very little data to guide clinicians, several recent studies have been published that can direct clinical decision-making as guidelines continue to be refined and updated.
A multicenter trial of approximately 800 patients undergoing upper endoscopy found a significant difference in rates of retained gastric contents between those that underwent endoscopy who did and did not follow the ASA guidance on periprocedural management of GLP-1 RAs (12.7% vs 4.4%; P < .0001). However, there were no significant differences in rates of aborted procedures or unplanned intubations.
Furthermore, a multivariable analysis was performed controlling for GLP-1 RA type and other factors, which found the likelihood of gastric retention increased by 36% for every 1% increase in hemoglobin A1c. This study suggests that a more individualized approach to holding GLP-1 RA would be applicable rather than a universal periprocedural hold.6
More recently, a single-center study of nearly 600 patients undergoing upper endoscopy showed that while there were slightly increased rates of retained gastric contents (OR 3.80; P = .003) and aborted procedures (1.3% vs 0%; P = .02), the rates of adverse anesthesia events (hypoxia, etc) were similar between the groups and no cases of pulmonary aspiration were noted.7
One single-center study of 57 patients evaluated the safety of GLP-1 RAs in those undergoing endoscopic sleeve gastrectomy. GLP-1 RAs were continued on all patients, but all adhered to a liquid only diet for at least 24 hours prior to the procedure. There were no instances of retained gastric solids, aspiration, or hypoxia. This study suggests that with a 24-hour clear liquid diet and routine NPO recommendations prior to endoscopy, it would be safe to continue GLP-1 RAs. This study provides rationale for the AGA recommendation for a clear liquid diet 24 hours prior to endoscopic procedures for those on GLP-1 RAs.8
A study looking at those who underwent emergency surgery and endoscopy with claims data of use of GLP-1 RAs found an overall incidence of postoperative respiratory complications of 3.5% for those with GLP-1 RAs fill history vs 4.0% for those without (P = .12). Approximately 800 of the 24,000 patients identified had undergone endoscopic procedures for GI bleeding or food impaction. The study overall showed that preoperative use of GLP-1 RAs in patients undergoing surgery or endoscopy, evaluated as a combined group, was not associated with an increased risk of pulmonary complications.9
Lastly, a systematic review and meta-analysis that included 15 studies that quantified gastric emptying using various methods, including gastric emptying scintigraphy and acetaminophen absorption test, found that there was a quantifiable delay in gastric emptying of about 36 minutes, compared to placebo (P < .01), in patients using GLP-1 RAs. However, compared to standard periprocedural fasting, this delay is clinically insignificant and standard fasting protocols would still be appropriate for patients on GLP-1 RAs.10
These studies taken together suggest that while GLP-1 RAs can mildly increase the likelihood of retained gastric contents, there is no statistically significant increase in the risk of aspiration or other anesthesia complications. Furthermore, while decreased gastric emptying is a known effect of GLP-1 RAs, this effect may not be clinically significant in the context of standard periprocedural fasting protocols particularly when combined with a 24-hour clear liquid diet. These findings support at a minimum a more patient-specific strategy for periprocedural management of GLP-1 RAs.
Clinical Implications
These most recent studies, as well as prior studies and guidelines by various societies lead to a dilemma among endoscopists on proper patient counseling on GLP-1 RAs use before endoscopic procedures. Clinicians must balance the metabolic benefits of GLP-1 RAs with potential endoscopic complications and risks.
Holding therapy theoretically decreases aspiration risk and pulmonary complications, though evidence remains low to support this. Holding medication, however, affects glycemic control leading to potential rebound hyperglycemia which may impact and delay plans for endoscopy. With growing indications for the use of GLP-1 RAs, a more tailored patient-centered treatment plan may be required, especially with consideration of procedure indication and comorbidities.
Currently, practice patterns at different institutions vary widely, making standardization much more difficult. Some centers have opted to follow ASA guidelines of holding these medications up to 1 week prior to procedures, while others have continued therapy with no pre-procedural adjustments. This leaves endoscopists to deal with the downstream effects of inconvenience to patients, care delays, and financial considerations if procedures are postponed related to GLP-1 RAs use.
Future Directions
Future studies are needed to make further evidence-based recommendations. Studies should focus on stratifying risks and recommendations based on procedure type (EGD, colonoscopy, etc). More widespread implementation of gastric ultrasound can assist in real-time decision-making, albeit this would require expertise and dedicated time within the pre-procedural workflow. Randomized controlled trials comparing outcomes of patients who continue GLP-1 RAs vs those who discontinue stratified by baseline risk will be instrumental for making concrete guidelines that provide clarity on periprocedural management of GLP-1 RAs.
Conclusion
The periprocedural management of GLP-1 RAs remains a controversial topic that presents unique challenges in endoscopy. Several guidelines have been released by various stakeholders including anesthesiologists, gastroenterologists, and other prescribing providers. Clinical data remains limited with no robust evidence available to suggest that gastric emptying delays caused by GLP-1 RAs prior to endoscopic procedures significantly increases risk of aspiration, pulmonary complications, or other comorbidities. Evolving multi-society guidelines will be important to establish more consistent practices with reassessment of the data as new studies emerge. A multidisciplinary, individualized patient approach may be the best strategy for managing GLP-1 RAs for patients undergoing endoscopic procedures.
Dr. Sekar and Dr. Asamoah are based in the department of gastroenterology at MedStar Georgetown University Hospital, Washington, D.C. Dr. Sekar reports no conflicts of interest in regard to this article. Dr. Asamoah serves on the Johnson & Johnson advisory board for inflammatory bowel disease–related therapies.
References
1. Halim MA et al. Glucagon-Like Peptide-1 Inhibits Prandial Gastrointestinal Motility Through Myenteric Neuronal Mechanisms in Humans. J Clin Endocrinol Metab. 2018 Feb. doi: 10.1210/jc.2017-02006.
2. American Society of Anesthesiologists. American Society of Anesthesiologists releases consensus-based guidance on preoperative use of GLP-1 receptor agonists. 2023 Jun 20. www.asahq.org/about-asa/newsroom/news-releases/2023/06/american-society-of-anesthesiologists-consensus-based-guidance-on-preoperative
3. American Gastroenterological Association. GI multi-society statement regarding GLP-1 agonists and endoscopy. 2023 Jul 25. gastro.org/news/gi-multi-society-statement-regarding-glp-1-agonists-and-endoscopy/.
4. Hashash JG et al. AGA Rapid Clinical Practice Update on the Management of Patients Taking GLP-1 Receptor Agonists Prior to Endoscopy: Communication. Clin Gastroenterol Hepatol. 2024 Apr. doi: 10.1016/j.cgh.2023.11.002.
5. Kindel TL et al; American Gastroenterological Association; American Society for Metabolic and Bariatric Surgery; American Society of Anesthesiologists; International Society of Perioperative Care of Patients with Obesity; Society of American Gastrointestinal and Endoscopic Surgeons. Multi-society Clinical Practice Guidance for the Safe Use of Glucagon-like Peptide-1 Receptor Agonists in the Perioperative Period. Clin Gastroenterol Hepatol. 2024 Oct. doi: 10.1016/j.cgh.2024.10.003.
6. Phan J et al. Glucagon-Like Peptide Receptor Agonists Use Before Endoscopy Is Associated With Low Retained Gastric Contents: A Multicenter Cross-Sectional Analysis. Am J Gastroenterol. 2025 Mar. doi: 10.14309/ajg.0000000000002969.
7. Panchal S et al. Endoscopy and Anesthesia Outcomes Associated With Glucagon-like Peptide-1 Receptor Agonist use in Patients Undergoing Outpatient Upper Endoscopy. Gastrointest Endosc. 2025 Aug. doi:10.1016/j.gie.2025.01.004.
8. Maselli DB et al. Safe Continuation of glucagon-like Peptide 1 Receptor Agonists at Endoscopy: A Case Series of 57 Adults Undergoing Endoscopic Sleeve Gastroplasty. Obes Surg. 2024 Jul. doi: 10.1007/s11695-024-07278-2.
9. Dixit AA et al. Preoperative GLP-1 Receptor Agonist Use and Risk of Postoperative Respiratory Complications. JAMA. 2024 Apr. doi: 10.1001/jama.2024.5003.
10. Hiramoto B et al. Quantified Metrics of Gastric Emptying Delay by Glucagon-Like Peptide-1 Agonists: A systematic review and meta-analysis with insights for periprocedural management. Am J Gastroenterol. 2024 Jun. doi: 10.14309/ajg.0000000000002820.
The use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) has increased over the past several years and has become a cornerstone in both diabetes and weight loss management, particularly because of its unique combination of glucose control, weight reduction potential, and cardiac and metabolic benefits. However, increased use of these agents presents a dilemma in gastrointestinal endoscopy as it pertains to their safety and management during the periprocedural period.
highlighting gaps and future directions.
Pharmacology and Mechanisms of Action
GLP-1 RAs have several mechanisms of action that make them relevant in gastrointestinal endoscopy. These medications modulate glucose control via enhancement of glucose-dependent insulin secretion and reduction of postprandial glucagon, which promotes satiety and delays gastric emptying. This delay in gastric emptying mediated by vagal pathways has been postulated to increase gastric residuals, posing a risk for aspiration during anesthesia.1
It is important to also consider the pharmacokinetics of GLP-1 RAs, as some have shorter half-lives on the order of several hours, like exenatide, while others, like semaglutide, are dosed weekly. Additionally, common side effects of GLP-1 RAs include nausea, vomiting, bloating, and early satiety, which pose challenges for patients undergoing endoscopic procedures.
Current Guidelines
Various societies have published guidelines on the periprocedural use of GLP-1 RAs. The American Society of Anesthesiologist (ASA) in 2023 presented early recommendations to hold GLP-1 RAs either day of procedure or week prior depending on pharmacokinetics, because of the risk of delayed gastric emptying and increased potential for aspiration.2 Soon thereafter, a multi-gastroenterology society guideline was released stating more data is needed to decide if GLP-1 RAs need to be held prior to endoscopic procedures.3
In early 2024, the American Gastroenterological Association (AGA) published a rapid clinical update that advocated for a more individualized approach, particularly in light of limited overall data for GLP-1 RAs and endoscopic procedures.4 In asymptomatic patients who follow typical fasting protocols for procedures, it is generally safe to proceed with endoscopy without holding GLP-1 RAs. In symptomatic patients (nausea, abdominal distension, etc), the AGA advises additional precautions, including performing transabdominal ultrasound if feasible to assess retained gastric contents. The AGA also suggests placing a patient on a clear liquid diet the day prior to the procedure — rather than holding GLP-1 RAs — as another reasonable strategy.
The guidelines continue to evolve with newer multi-society guidelines establishing best practices. While initially in 2023 the ASA did recommend holding these medications prior to endoscopy, the initial guidance was based on expert opinion with limited evidence. Newer multi-society guidance published jointly by the ASA along with various gastroenterology societies, including the AGA in December 2024, takes a more nuanced approach.5
The newer guidelines include two main recommendations:
1. Periprocedural management of GLP-1 RAs should be a joint decision among the procedural, anesthesia, and prescribing team balancing metabolic needs vs patient risks.
- In a low-risk patient, one that is asymptomatic and on standard dosing, among other factors, the guidance states that GLP-1 RAs can be continued.
- In higher-risk patients, the original guidance of holding a day or a week prior to endoscopic procedures should be followed.
2. Periprocedural management of GLP-1 RAs should attempt to minimize the aspiration risks loosely associated with delayed gastric emptying.
- Consider a 24-hour clear liquid diet a day prior to the procedure and transabdominal ultrasound to check gastric contents.
- It is acknowledged that this guidance is based on limited evidence and will be evolving as new medications and data are released.
Recent Clinical Studies
Although there is very little data to guide clinicians, several recent studies have been published that can direct clinical decision-making as guidelines continue to be refined and updated.
A multicenter trial of approximately 800 patients undergoing upper endoscopy found a significant difference in rates of retained gastric contents between those that underwent endoscopy who did and did not follow the ASA guidance on periprocedural management of GLP-1 RAs (12.7% vs 4.4%; P < .0001). However, there were no significant differences in rates of aborted procedures or unplanned intubations.
Furthermore, a multivariable analysis was performed controlling for GLP-1 RA type and other factors, which found the likelihood of gastric retention increased by 36% for every 1% increase in hemoglobin A1c. This study suggests that a more individualized approach to holding GLP-1 RA would be applicable rather than a universal periprocedural hold.6
More recently, a single-center study of nearly 600 patients undergoing upper endoscopy showed that while there were slightly increased rates of retained gastric contents (OR 3.80; P = .003) and aborted procedures (1.3% vs 0%; P = .02), the rates of adverse anesthesia events (hypoxia, etc) were similar between the groups and no cases of pulmonary aspiration were noted.7
One single-center study of 57 patients evaluated the safety of GLP-1 RAs in those undergoing endoscopic sleeve gastrectomy. GLP-1 RAs were continued on all patients, but all adhered to a liquid only diet for at least 24 hours prior to the procedure. There were no instances of retained gastric solids, aspiration, or hypoxia. This study suggests that with a 24-hour clear liquid diet and routine NPO recommendations prior to endoscopy, it would be safe to continue GLP-1 RAs. This study provides rationale for the AGA recommendation for a clear liquid diet 24 hours prior to endoscopic procedures for those on GLP-1 RAs.8
A study looking at those who underwent emergency surgery and endoscopy with claims data of use of GLP-1 RAs found an overall incidence of postoperative respiratory complications of 3.5% for those with GLP-1 RAs fill history vs 4.0% for those without (P = .12). Approximately 800 of the 24,000 patients identified had undergone endoscopic procedures for GI bleeding or food impaction. The study overall showed that preoperative use of GLP-1 RAs in patients undergoing surgery or endoscopy, evaluated as a combined group, was not associated with an increased risk of pulmonary complications.9
Lastly, a systematic review and meta-analysis that included 15 studies that quantified gastric emptying using various methods, including gastric emptying scintigraphy and acetaminophen absorption test, found that there was a quantifiable delay in gastric emptying of about 36 minutes, compared to placebo (P < .01), in patients using GLP-1 RAs. However, compared to standard periprocedural fasting, this delay is clinically insignificant and standard fasting protocols would still be appropriate for patients on GLP-1 RAs.10
These studies taken together suggest that while GLP-1 RAs can mildly increase the likelihood of retained gastric contents, there is no statistically significant increase in the risk of aspiration or other anesthesia complications. Furthermore, while decreased gastric emptying is a known effect of GLP-1 RAs, this effect may not be clinically significant in the context of standard periprocedural fasting protocols particularly when combined with a 24-hour clear liquid diet. These findings support at a minimum a more patient-specific strategy for periprocedural management of GLP-1 RAs.
Clinical Implications
These most recent studies, as well as prior studies and guidelines by various societies lead to a dilemma among endoscopists on proper patient counseling on GLP-1 RAs use before endoscopic procedures. Clinicians must balance the metabolic benefits of GLP-1 RAs with potential endoscopic complications and risks.
Holding therapy theoretically decreases aspiration risk and pulmonary complications, though evidence remains low to support this. Holding medication, however, affects glycemic control leading to potential rebound hyperglycemia which may impact and delay plans for endoscopy. With growing indications for the use of GLP-1 RAs, a more tailored patient-centered treatment plan may be required, especially with consideration of procedure indication and comorbidities.
Currently, practice patterns at different institutions vary widely, making standardization much more difficult. Some centers have opted to follow ASA guidelines of holding these medications up to 1 week prior to procedures, while others have continued therapy with no pre-procedural adjustments. This leaves endoscopists to deal with the downstream effects of inconvenience to patients, care delays, and financial considerations if procedures are postponed related to GLP-1 RAs use.
Future Directions
Future studies are needed to make further evidence-based recommendations. Studies should focus on stratifying risks and recommendations based on procedure type (EGD, colonoscopy, etc). More widespread implementation of gastric ultrasound can assist in real-time decision-making, albeit this would require expertise and dedicated time within the pre-procedural workflow. Randomized controlled trials comparing outcomes of patients who continue GLP-1 RAs vs those who discontinue stratified by baseline risk will be instrumental for making concrete guidelines that provide clarity on periprocedural management of GLP-1 RAs.
Conclusion
The periprocedural management of GLP-1 RAs remains a controversial topic that presents unique challenges in endoscopy. Several guidelines have been released by various stakeholders including anesthesiologists, gastroenterologists, and other prescribing providers. Clinical data remains limited with no robust evidence available to suggest that gastric emptying delays caused by GLP-1 RAs prior to endoscopic procedures significantly increases risk of aspiration, pulmonary complications, or other comorbidities. Evolving multi-society guidelines will be important to establish more consistent practices with reassessment of the data as new studies emerge. A multidisciplinary, individualized patient approach may be the best strategy for managing GLP-1 RAs for patients undergoing endoscopic procedures.
Dr. Sekar and Dr. Asamoah are based in the department of gastroenterology at MedStar Georgetown University Hospital, Washington, D.C. Dr. Sekar reports no conflicts of interest in regard to this article. Dr. Asamoah serves on the Johnson & Johnson advisory board for inflammatory bowel disease–related therapies.
References
1. Halim MA et al. Glucagon-Like Peptide-1 Inhibits Prandial Gastrointestinal Motility Through Myenteric Neuronal Mechanisms in Humans. J Clin Endocrinol Metab. 2018 Feb. doi: 10.1210/jc.2017-02006.
2. American Society of Anesthesiologists. American Society of Anesthesiologists releases consensus-based guidance on preoperative use of GLP-1 receptor agonists. 2023 Jun 20. www.asahq.org/about-asa/newsroom/news-releases/2023/06/american-society-of-anesthesiologists-consensus-based-guidance-on-preoperative
3. American Gastroenterological Association. GI multi-society statement regarding GLP-1 agonists and endoscopy. 2023 Jul 25. gastro.org/news/gi-multi-society-statement-regarding-glp-1-agonists-and-endoscopy/.
4. Hashash JG et al. AGA Rapid Clinical Practice Update on the Management of Patients Taking GLP-1 Receptor Agonists Prior to Endoscopy: Communication. Clin Gastroenterol Hepatol. 2024 Apr. doi: 10.1016/j.cgh.2023.11.002.
5. Kindel TL et al; American Gastroenterological Association; American Society for Metabolic and Bariatric Surgery; American Society of Anesthesiologists; International Society of Perioperative Care of Patients with Obesity; Society of American Gastrointestinal and Endoscopic Surgeons. Multi-society Clinical Practice Guidance for the Safe Use of Glucagon-like Peptide-1 Receptor Agonists in the Perioperative Period. Clin Gastroenterol Hepatol. 2024 Oct. doi: 10.1016/j.cgh.2024.10.003.
6. Phan J et al. Glucagon-Like Peptide Receptor Agonists Use Before Endoscopy Is Associated With Low Retained Gastric Contents: A Multicenter Cross-Sectional Analysis. Am J Gastroenterol. 2025 Mar. doi: 10.14309/ajg.0000000000002969.
7. Panchal S et al. Endoscopy and Anesthesia Outcomes Associated With Glucagon-like Peptide-1 Receptor Agonist use in Patients Undergoing Outpatient Upper Endoscopy. Gastrointest Endosc. 2025 Aug. doi:10.1016/j.gie.2025.01.004.
8. Maselli DB et al. Safe Continuation of glucagon-like Peptide 1 Receptor Agonists at Endoscopy: A Case Series of 57 Adults Undergoing Endoscopic Sleeve Gastroplasty. Obes Surg. 2024 Jul. doi: 10.1007/s11695-024-07278-2.
9. Dixit AA et al. Preoperative GLP-1 Receptor Agonist Use and Risk of Postoperative Respiratory Complications. JAMA. 2024 Apr. doi: 10.1001/jama.2024.5003.
10. Hiramoto B et al. Quantified Metrics of Gastric Emptying Delay by Glucagon-Like Peptide-1 Agonists: A systematic review and meta-analysis with insights for periprocedural management. Am J Gastroenterol. 2024 Jun. doi: 10.14309/ajg.0000000000002820.
Less Invasive Sponge Test Stratifies Risk in Patients With Barrett’s Esophagus
The biomarker risk panel collected by the panesophageal Cytosponge-on-a-string in more than 900 UK patients helped identify those at highest risk for dysplasia or cancer and needing endoscopy. It was found safe for following low-risk patients who did not need endoscopy.
Endoscopic surveillance is the clinical standard for BE, but its effectiveness is inconsistent, wrote Rebecca C. Fitzgerald, MD, AGAF, professor in the Early Cancer Institute at the University of Cambridge in Cambridge, England, and colleagues in The Lancet.
“It is often performed by nonspecialists, and recent trials show that around 10% of cases of dysplasia and cancer are missed, which means some patients re-present within a year of their surveillance procedure with a symptomatic cancer that should have been diagnosed earlier,” Fitzgerald told GI & Hepatology News.
Moreover, repeated endoscopy monitoring is stressful. “A simple nonendoscopic capsule sponge test done nearer to home is less scary and could be less operator-dependent. By reducing the burden of endoscopy in patients at very low risk we can focus more on the patients at higher risk,” she said.
In 2022, her research group had reported that the capsule sponge test, coupled with a centralized lab test for p53 and atypia, can risk-stratify patients into low-, moderate-, and high-risk groups. “In the current study, we wanted to check this risk stratification capsule sponge test in the real world. Our main aim was to see if we could conform the 2022 results with the hypothesis that the low-risk patients — more than 50% of patients in surveillance — would have a risk of high-grade dysplasia or cancer that was sufficiently low — that is, less than from 3% — and could therefore have follow-up with the capsule sponge without requiring endoscopy.”
The investigators hypothesized that the 15% at high risk would have a significant chance of dysplasia warranting endoscopy in a specialist center.
“Our results showed that in the low-risk group the risk of high-grade dysplasia or cancer was 0.4%, suggesting these patients could be offered follow-up with the capsule sponge test,” Fitzgerald said.
The high-risk group with a double biomarker positive (p53 and atypia) had an 85% risk for dysplasia or cancer. “We call this a tier 1 or ultra-high risk, and this suggests these cases merit a specialist endoscopy in a center that could treat the dysplasia/cancer,” she said.
Study Details
Adult participants (n = 910) were recruited from August 2020 to December 2024 in two multicenter, prospective, pragmatic implementation studies from 13 hospitals. Patients with nondysplastic BE on last endoscopy had a capsule sponge test.
Patient risk was assigned as low (clinical and capsule sponge biomarkers negative), moderate (negative for capsule sponge biomarkers, positive clinical biomarkers: age, sex, and segment length), or high risk (p53 abnormality, glandular atypia regardless of clinical biomarkers, or both). The primary outcome was a diagnosis of high-grade dysplasia or cancer necessitating treatment, according to the risk group.
In the cohort, 138 (15%) were classified as having high risk, 283 (31%) had moderate risk, and 489 (54%) had low risk.
The positive predictive value for any dysplasia or worse in the high-risk group was 37.7% (95% CI, 29.7-46.4). Patients with both atypia and aberrant p53 had the highest risk for high-grade dysplasia or cancer with a relative risk of 135.8 (95% CI, 32.7-564.0) vs the low-risk group.
The prevalence of high-grade dysplasia or cancer in the low-risk group was, as mentioned, just 0.4% (95% CI, 0.1-1.6), while the negative predictive value for any dysplasia or cancer was 97.8% (95% CI, 95.9-98.8). Applying a machine learning algorithm reduced the proportion needing p53 pathology review to 32% without missing any positive cases.
Offering a US perspective on the study, Nicholas J. Shaheen, MD, MPH, AGAF, professor of medicine and director of the NC Translational & Clinical Sciences Institute at the University of North Carolina School of Medicine in Chapel Hill, called the findings “very provocative.”
“We have known for some time that nonendoscopic techniques could be used to screen for Barrett’s esophagus and esophageal cancer, allowing us to screen larger groups of patients in a more cost-effective manner compared to traditional upper endoscopy,” he told GI & Hepatology News. “This study suggests that, in addition to case-finding for Barrett’s [esophagus], a nonendoscopic sponge-based technique can also help us stratify risk, finding cases that either already harbor cancer or are at high risk to do so.”
Shaheen said these cases deserve immediate attention since they are most likely to benefit from timely endoscopic intervention. “The study also suggests that a nonendoscopic result could someday be used to decide subsequent follow-up, with low-risk patients undergoing further nonendoscopic surveillance, while higher-risk patients would move on to endoscopy. Such a paradigm could unburden our endoscopy units from low-risk patients unlikely to benefit from endoscopy as well as increase the numbers of patients who are able to be screened.”
Fitzgerald added, “The GI community is realizing that we need a better approach to managing patients with Barrett’s [esophagus]. In the UK this evidence is being considered by our guideline committee, and it would influence the upcoming guidelines in 2025 with a requirement to continue to audit the results. Outside of the UK we hope this will pave the way for nonendoscopic approaches to Barrett’s [esophagus] surveillance.”
One ongoing goal is to optimize the biomarkers, Fitzgerald said. “For patients with longer segments we would like to add additional genomic biomarkers to refine the risk predictions,” she said. “We need a more operator-independent, consistent method for monitoring Barrett’s [esophagus]. This large real-world study is highly encouraging for a more personalized and patient-friendly approach to Barrett’s [esophagus] surveillance.”
This study was funded by Innovate UK, Cancer Research UK, National Health Service England Cancer Alliance. Cytosponge technology is licensed by the Medical Research Council to Medtronic. Fitzgerald declared holding patents related to this test. Fitzgerald reported being a shareholder in Cyted Health.
Shaheen reported receiving research funding from Lucid Diagnostics and Cyted Health, both of which are manufacturers of nonendoscopic screening devices for BE.
A version of this article appeared on Medscape.com.
The biomarker risk panel collected by the panesophageal Cytosponge-on-a-string in more than 900 UK patients helped identify those at highest risk for dysplasia or cancer and needing endoscopy. It was found safe for following low-risk patients who did not need endoscopy.
Endoscopic surveillance is the clinical standard for BE, but its effectiveness is inconsistent, wrote Rebecca C. Fitzgerald, MD, AGAF, professor in the Early Cancer Institute at the University of Cambridge in Cambridge, England, and colleagues in The Lancet.
“It is often performed by nonspecialists, and recent trials show that around 10% of cases of dysplasia and cancer are missed, which means some patients re-present within a year of their surveillance procedure with a symptomatic cancer that should have been diagnosed earlier,” Fitzgerald told GI & Hepatology News.
Moreover, repeated endoscopy monitoring is stressful. “A simple nonendoscopic capsule sponge test done nearer to home is less scary and could be less operator-dependent. By reducing the burden of endoscopy in patients at very low risk we can focus more on the patients at higher risk,” she said.
In 2022, her research group had reported that the capsule sponge test, coupled with a centralized lab test for p53 and atypia, can risk-stratify patients into low-, moderate-, and high-risk groups. “In the current study, we wanted to check this risk stratification capsule sponge test in the real world. Our main aim was to see if we could conform the 2022 results with the hypothesis that the low-risk patients — more than 50% of patients in surveillance — would have a risk of high-grade dysplasia or cancer that was sufficiently low — that is, less than from 3% — and could therefore have follow-up with the capsule sponge without requiring endoscopy.”
The investigators hypothesized that the 15% at high risk would have a significant chance of dysplasia warranting endoscopy in a specialist center.
“Our results showed that in the low-risk group the risk of high-grade dysplasia or cancer was 0.4%, suggesting these patients could be offered follow-up with the capsule sponge test,” Fitzgerald said.
The high-risk group with a double biomarker positive (p53 and atypia) had an 85% risk for dysplasia or cancer. “We call this a tier 1 or ultra-high risk, and this suggests these cases merit a specialist endoscopy in a center that could treat the dysplasia/cancer,” she said.
Study Details
Adult participants (n = 910) were recruited from August 2020 to December 2024 in two multicenter, prospective, pragmatic implementation studies from 13 hospitals. Patients with nondysplastic BE on last endoscopy had a capsule sponge test.
Patient risk was assigned as low (clinical and capsule sponge biomarkers negative), moderate (negative for capsule sponge biomarkers, positive clinical biomarkers: age, sex, and segment length), or high risk (p53 abnormality, glandular atypia regardless of clinical biomarkers, or both). The primary outcome was a diagnosis of high-grade dysplasia or cancer necessitating treatment, according to the risk group.
In the cohort, 138 (15%) were classified as having high risk, 283 (31%) had moderate risk, and 489 (54%) had low risk.
The positive predictive value for any dysplasia or worse in the high-risk group was 37.7% (95% CI, 29.7-46.4). Patients with both atypia and aberrant p53 had the highest risk for high-grade dysplasia or cancer with a relative risk of 135.8 (95% CI, 32.7-564.0) vs the low-risk group.
The prevalence of high-grade dysplasia or cancer in the low-risk group was, as mentioned, just 0.4% (95% CI, 0.1-1.6), while the negative predictive value for any dysplasia or cancer was 97.8% (95% CI, 95.9-98.8). Applying a machine learning algorithm reduced the proportion needing p53 pathology review to 32% without missing any positive cases.
Offering a US perspective on the study, Nicholas J. Shaheen, MD, MPH, AGAF, professor of medicine and director of the NC Translational & Clinical Sciences Institute at the University of North Carolina School of Medicine in Chapel Hill, called the findings “very provocative.”
“We have known for some time that nonendoscopic techniques could be used to screen for Barrett’s esophagus and esophageal cancer, allowing us to screen larger groups of patients in a more cost-effective manner compared to traditional upper endoscopy,” he told GI & Hepatology News. “This study suggests that, in addition to case-finding for Barrett’s [esophagus], a nonendoscopic sponge-based technique can also help us stratify risk, finding cases that either already harbor cancer or are at high risk to do so.”
Shaheen said these cases deserve immediate attention since they are most likely to benefit from timely endoscopic intervention. “The study also suggests that a nonendoscopic result could someday be used to decide subsequent follow-up, with low-risk patients undergoing further nonendoscopic surveillance, while higher-risk patients would move on to endoscopy. Such a paradigm could unburden our endoscopy units from low-risk patients unlikely to benefit from endoscopy as well as increase the numbers of patients who are able to be screened.”
Fitzgerald added, “The GI community is realizing that we need a better approach to managing patients with Barrett’s [esophagus]. In the UK this evidence is being considered by our guideline committee, and it would influence the upcoming guidelines in 2025 with a requirement to continue to audit the results. Outside of the UK we hope this will pave the way for nonendoscopic approaches to Barrett’s [esophagus] surveillance.”
One ongoing goal is to optimize the biomarkers, Fitzgerald said. “For patients with longer segments we would like to add additional genomic biomarkers to refine the risk predictions,” she said. “We need a more operator-independent, consistent method for monitoring Barrett’s [esophagus]. This large real-world study is highly encouraging for a more personalized and patient-friendly approach to Barrett’s [esophagus] surveillance.”
This study was funded by Innovate UK, Cancer Research UK, National Health Service England Cancer Alliance. Cytosponge technology is licensed by the Medical Research Council to Medtronic. Fitzgerald declared holding patents related to this test. Fitzgerald reported being a shareholder in Cyted Health.
Shaheen reported receiving research funding from Lucid Diagnostics and Cyted Health, both of which are manufacturers of nonendoscopic screening devices for BE.
A version of this article appeared on Medscape.com.
The biomarker risk panel collected by the panesophageal Cytosponge-on-a-string in more than 900 UK patients helped identify those at highest risk for dysplasia or cancer and needing endoscopy. It was found safe for following low-risk patients who did not need endoscopy.
Endoscopic surveillance is the clinical standard for BE, but its effectiveness is inconsistent, wrote Rebecca C. Fitzgerald, MD, AGAF, professor in the Early Cancer Institute at the University of Cambridge in Cambridge, England, and colleagues in The Lancet.
“It is often performed by nonspecialists, and recent trials show that around 10% of cases of dysplasia and cancer are missed, which means some patients re-present within a year of their surveillance procedure with a symptomatic cancer that should have been diagnosed earlier,” Fitzgerald told GI & Hepatology News.
Moreover, repeated endoscopy monitoring is stressful. “A simple nonendoscopic capsule sponge test done nearer to home is less scary and could be less operator-dependent. By reducing the burden of endoscopy in patients at very low risk we can focus more on the patients at higher risk,” she said.
In 2022, her research group had reported that the capsule sponge test, coupled with a centralized lab test for p53 and atypia, can risk-stratify patients into low-, moderate-, and high-risk groups. “In the current study, we wanted to check this risk stratification capsule sponge test in the real world. Our main aim was to see if we could conform the 2022 results with the hypothesis that the low-risk patients — more than 50% of patients in surveillance — would have a risk of high-grade dysplasia or cancer that was sufficiently low — that is, less than from 3% — and could therefore have follow-up with the capsule sponge without requiring endoscopy.”
The investigators hypothesized that the 15% at high risk would have a significant chance of dysplasia warranting endoscopy in a specialist center.
“Our results showed that in the low-risk group the risk of high-grade dysplasia or cancer was 0.4%, suggesting these patients could be offered follow-up with the capsule sponge test,” Fitzgerald said.
The high-risk group with a double biomarker positive (p53 and atypia) had an 85% risk for dysplasia or cancer. “We call this a tier 1 or ultra-high risk, and this suggests these cases merit a specialist endoscopy in a center that could treat the dysplasia/cancer,” she said.
Study Details
Adult participants (n = 910) were recruited from August 2020 to December 2024 in two multicenter, prospective, pragmatic implementation studies from 13 hospitals. Patients with nondysplastic BE on last endoscopy had a capsule sponge test.
Patient risk was assigned as low (clinical and capsule sponge biomarkers negative), moderate (negative for capsule sponge biomarkers, positive clinical biomarkers: age, sex, and segment length), or high risk (p53 abnormality, glandular atypia regardless of clinical biomarkers, or both). The primary outcome was a diagnosis of high-grade dysplasia or cancer necessitating treatment, according to the risk group.
In the cohort, 138 (15%) were classified as having high risk, 283 (31%) had moderate risk, and 489 (54%) had low risk.
The positive predictive value for any dysplasia or worse in the high-risk group was 37.7% (95% CI, 29.7-46.4). Patients with both atypia and aberrant p53 had the highest risk for high-grade dysplasia or cancer with a relative risk of 135.8 (95% CI, 32.7-564.0) vs the low-risk group.
The prevalence of high-grade dysplasia or cancer in the low-risk group was, as mentioned, just 0.4% (95% CI, 0.1-1.6), while the negative predictive value for any dysplasia or cancer was 97.8% (95% CI, 95.9-98.8). Applying a machine learning algorithm reduced the proportion needing p53 pathology review to 32% without missing any positive cases.
Offering a US perspective on the study, Nicholas J. Shaheen, MD, MPH, AGAF, professor of medicine and director of the NC Translational & Clinical Sciences Institute at the University of North Carolina School of Medicine in Chapel Hill, called the findings “very provocative.”
“We have known for some time that nonendoscopic techniques could be used to screen for Barrett’s esophagus and esophageal cancer, allowing us to screen larger groups of patients in a more cost-effective manner compared to traditional upper endoscopy,” he told GI & Hepatology News. “This study suggests that, in addition to case-finding for Barrett’s [esophagus], a nonendoscopic sponge-based technique can also help us stratify risk, finding cases that either already harbor cancer or are at high risk to do so.”
Shaheen said these cases deserve immediate attention since they are most likely to benefit from timely endoscopic intervention. “The study also suggests that a nonendoscopic result could someday be used to decide subsequent follow-up, with low-risk patients undergoing further nonendoscopic surveillance, while higher-risk patients would move on to endoscopy. Such a paradigm could unburden our endoscopy units from low-risk patients unlikely to benefit from endoscopy as well as increase the numbers of patients who are able to be screened.”
Fitzgerald added, “The GI community is realizing that we need a better approach to managing patients with Barrett’s [esophagus]. In the UK this evidence is being considered by our guideline committee, and it would influence the upcoming guidelines in 2025 with a requirement to continue to audit the results. Outside of the UK we hope this will pave the way for nonendoscopic approaches to Barrett’s [esophagus] surveillance.”
One ongoing goal is to optimize the biomarkers, Fitzgerald said. “For patients with longer segments we would like to add additional genomic biomarkers to refine the risk predictions,” she said. “We need a more operator-independent, consistent method for monitoring Barrett’s [esophagus]. This large real-world study is highly encouraging for a more personalized and patient-friendly approach to Barrett’s [esophagus] surveillance.”
This study was funded by Innovate UK, Cancer Research UK, National Health Service England Cancer Alliance. Cytosponge technology is licensed by the Medical Research Council to Medtronic. Fitzgerald declared holding patents related to this test. Fitzgerald reported being a shareholder in Cyted Health.
Shaheen reported receiving research funding from Lucid Diagnostics and Cyted Health, both of which are manufacturers of nonendoscopic screening devices for BE.
A version of this article appeared on Medscape.com.
Hypothyroidism Linked to Gut Microbiome Disturbances
, according to results of a study.
“[The research] supports the idea that improving gut health could have far-reaching effects beyond digestion, possibly even helping to prevent autoimmune diseases, such as Hashimoto thyroiditis,” said senior author Ruchi Mathur, MD, director of the Diabetes Outpatient Treatment and Education Center and director of Clinical Operations of Medically Associated Science and Technology, at Cedars-Sinai in Los Angeles, in a press statement for the study, which was presented at ENDO 2025: The Endocrine Society Annual Meeting.
“These findings open the door to new screening and prevention strategies,” Mathur added. “For example, doctors may begin to monitor thyroid health more closely in patients with SIBO, and vice versa.”
With some small studies previously suggesting an association between the gut microbiome and hypothyroidism, Mathur and colleagues further explored the relationship in two analyses.
Assessing the Role of the Small Bowel
For the first, they evaluated data on 49 patients with Hashimoto thyroiditis (HT) and 323 controls without the condition from their REIMAGINE trial, which included small bowel fluid samples from upper endoscopies and DNA sequencing.
In the study, all patients with HT were treated with thyroid replacement (levothyroxine), hence, there were notably no significant differences between the two groups in terms of thyroid stimulating hormone (TSH) levels.
Despite the lack of those differences, patients with HT had a prevalence of SIBO more than twice that of the control group, independent of gender (33% vs 15%; odds ratio, 2.71; P = .005).
When the two groups were further subdivided into two groups each — those with and without SIBO — significant further variations of microbial diversity were observed between those with and without HT, Mathur told GI & Hepatology News.
“Interestingly, we saw the small bowel microbiome was not only different in SIBO-positive patients, including higher gram negatives, which is to be expected, but that the presence or absence of hypothyroidism itself was associated with specific patterns of these gram-negative bacteria,” she explained.
“In addition, when we looked at hypothyroidism without SIBO present, there were also changes between groups, such as higher Neisseria in the hypothyroid group.”
“All these findings are novel as this is the first paper to look specifically at the small bowel,” she added, noting that previous smaller studies have focused more on evaluation of stool samples.
“We believe the small bowel is the most metabolically active area of the intestine and plays an important role in metabolism,” Mathur noted. “Thus, the microbial changes here are likely more physiologically significant than the patterns seen in stool.”
Further Findings from a Large Population
In a separate analysis, the team evaluated data from the TriNetX database on the 10-year incidence of developing SIBO among 1.1 million subjects with hypothyroidism in the US compared with 1 million controls.
They found that people with hypothyroidism were approximately twice as likely to develop SIBO compared with those without hypothyroidism (relative risk [RR], 2.20).
Furthermore, those with HT, in particular, had an even higher risk, at 2.4 times the controls (RR, 2.40).
Treatment with levothyroxine decreased the risk of developing SIBO in hypothyroidism (RR, 0.33) and HT (RR, 0.78) vs those who did not receive treatment.
Mechanisms?
However, the fact that differences in SIBO were observed even between people who were treated for HT and those without the condition in the first analysis, and hence had similar TSH levels, was notable, Mathur said.
“This suggests that perhaps there are other factors aside from TSH levels and free T4 that are at play here,” she said. “Some people have theorized that perhaps delayed gut motility in hypothyroidism promotes the development of SIBO; however, there are many other factors within this complex interplay between the microbiome and the thyroid that could also be playing a role.”
“For example, SIBO leads to inflammation and weakening of the gut barrier,” Mathur explained.
Furthermore, “levothyroxine absorption and cycling of the thyroid hormone occurs predominantly in the small bowel, [while the] microbiome plays a key role in the absorption of iron, selenium, iodine, and zinc, which are critical for thyroid function.”
Overall, “further research is needed to understand how the mechanisms are affected during the development of SIBO and hypothyroidism,” Mathur said.
Assessment of Changes Over Time Anticipated
Commenting on the research, Gregory A. Brent, MD, senior executive academic vice-chair of the Department of Medicine and professor of medicine and physiology at the David Geffen School of Medicine at University of California Los Angeles said the study is indeed novel.
“This, to my knowledge, is the first investigation to link characteristics of the small bowel microbiome with hypothyroidism,” Brent told GI & Hepatology News.
While any clinical significance has yet to be determined, “the association of these small bowel microbiome changes with hypothyroidism may have implications for contributing to the onset of autoimmune hypothyroidism in susceptible populations as well as influences on levothyroxine absorption in hypothyroid patients on levothyroxine therapy,” Brent said.
With the SIBO differences observed even among treated patients with vs without HT, “it seems less likely that the microbiome changes are the result of reduced thyroid hormone signaling,” Brent noted.
Furthermore, a key piece of the puzzle will be to observe the microbiome changes over time, he added.
“These studies were at a single time point [and] longitudinal studies will be especially important to see how the association changes over time and are influenced by the treatment of hypothyroidism and of SIBO,” Brent said.
The authors and Brent had no disclosures to report.
A version of this article appeared on Medscape.com.
, according to results of a study.
“[The research] supports the idea that improving gut health could have far-reaching effects beyond digestion, possibly even helping to prevent autoimmune diseases, such as Hashimoto thyroiditis,” said senior author Ruchi Mathur, MD, director of the Diabetes Outpatient Treatment and Education Center and director of Clinical Operations of Medically Associated Science and Technology, at Cedars-Sinai in Los Angeles, in a press statement for the study, which was presented at ENDO 2025: The Endocrine Society Annual Meeting.
“These findings open the door to new screening and prevention strategies,” Mathur added. “For example, doctors may begin to monitor thyroid health more closely in patients with SIBO, and vice versa.”
With some small studies previously suggesting an association between the gut microbiome and hypothyroidism, Mathur and colleagues further explored the relationship in two analyses.
Assessing the Role of the Small Bowel
For the first, they evaluated data on 49 patients with Hashimoto thyroiditis (HT) and 323 controls without the condition from their REIMAGINE trial, which included small bowel fluid samples from upper endoscopies and DNA sequencing.
In the study, all patients with HT were treated with thyroid replacement (levothyroxine), hence, there were notably no significant differences between the two groups in terms of thyroid stimulating hormone (TSH) levels.
Despite the lack of those differences, patients with HT had a prevalence of SIBO more than twice that of the control group, independent of gender (33% vs 15%; odds ratio, 2.71; P = .005).
When the two groups were further subdivided into two groups each — those with and without SIBO — significant further variations of microbial diversity were observed between those with and without HT, Mathur told GI & Hepatology News.
“Interestingly, we saw the small bowel microbiome was not only different in SIBO-positive patients, including higher gram negatives, which is to be expected, but that the presence or absence of hypothyroidism itself was associated with specific patterns of these gram-negative bacteria,” she explained.
“In addition, when we looked at hypothyroidism without SIBO present, there were also changes between groups, such as higher Neisseria in the hypothyroid group.”
“All these findings are novel as this is the first paper to look specifically at the small bowel,” she added, noting that previous smaller studies have focused more on evaluation of stool samples.
“We believe the small bowel is the most metabolically active area of the intestine and plays an important role in metabolism,” Mathur noted. “Thus, the microbial changes here are likely more physiologically significant than the patterns seen in stool.”
Further Findings from a Large Population
In a separate analysis, the team evaluated data from the TriNetX database on the 10-year incidence of developing SIBO among 1.1 million subjects with hypothyroidism in the US compared with 1 million controls.
They found that people with hypothyroidism were approximately twice as likely to develop SIBO compared with those without hypothyroidism (relative risk [RR], 2.20).
Furthermore, those with HT, in particular, had an even higher risk, at 2.4 times the controls (RR, 2.40).
Treatment with levothyroxine decreased the risk of developing SIBO in hypothyroidism (RR, 0.33) and HT (RR, 0.78) vs those who did not receive treatment.
Mechanisms?
However, the fact that differences in SIBO were observed even between people who were treated for HT and those without the condition in the first analysis, and hence had similar TSH levels, was notable, Mathur said.
“This suggests that perhaps there are other factors aside from TSH levels and free T4 that are at play here,” she said. “Some people have theorized that perhaps delayed gut motility in hypothyroidism promotes the development of SIBO; however, there are many other factors within this complex interplay between the microbiome and the thyroid that could also be playing a role.”
“For example, SIBO leads to inflammation and weakening of the gut barrier,” Mathur explained.
Furthermore, “levothyroxine absorption and cycling of the thyroid hormone occurs predominantly in the small bowel, [while the] microbiome plays a key role in the absorption of iron, selenium, iodine, and zinc, which are critical for thyroid function.”
Overall, “further research is needed to understand how the mechanisms are affected during the development of SIBO and hypothyroidism,” Mathur said.
Assessment of Changes Over Time Anticipated
Commenting on the research, Gregory A. Brent, MD, senior executive academic vice-chair of the Department of Medicine and professor of medicine and physiology at the David Geffen School of Medicine at University of California Los Angeles said the study is indeed novel.
“This, to my knowledge, is the first investigation to link characteristics of the small bowel microbiome with hypothyroidism,” Brent told GI & Hepatology News.
While any clinical significance has yet to be determined, “the association of these small bowel microbiome changes with hypothyroidism may have implications for contributing to the onset of autoimmune hypothyroidism in susceptible populations as well as influences on levothyroxine absorption in hypothyroid patients on levothyroxine therapy,” Brent said.
With the SIBO differences observed even among treated patients with vs without HT, “it seems less likely that the microbiome changes are the result of reduced thyroid hormone signaling,” Brent noted.
Furthermore, a key piece of the puzzle will be to observe the microbiome changes over time, he added.
“These studies were at a single time point [and] longitudinal studies will be especially important to see how the association changes over time and are influenced by the treatment of hypothyroidism and of SIBO,” Brent said.
The authors and Brent had no disclosures to report.
A version of this article appeared on Medscape.com.
, according to results of a study.
“[The research] supports the idea that improving gut health could have far-reaching effects beyond digestion, possibly even helping to prevent autoimmune diseases, such as Hashimoto thyroiditis,” said senior author Ruchi Mathur, MD, director of the Diabetes Outpatient Treatment and Education Center and director of Clinical Operations of Medically Associated Science and Technology, at Cedars-Sinai in Los Angeles, in a press statement for the study, which was presented at ENDO 2025: The Endocrine Society Annual Meeting.
“These findings open the door to new screening and prevention strategies,” Mathur added. “For example, doctors may begin to monitor thyroid health more closely in patients with SIBO, and vice versa.”
With some small studies previously suggesting an association between the gut microbiome and hypothyroidism, Mathur and colleagues further explored the relationship in two analyses.
Assessing the Role of the Small Bowel
For the first, they evaluated data on 49 patients with Hashimoto thyroiditis (HT) and 323 controls without the condition from their REIMAGINE trial, which included small bowel fluid samples from upper endoscopies and DNA sequencing.
In the study, all patients with HT were treated with thyroid replacement (levothyroxine), hence, there were notably no significant differences between the two groups in terms of thyroid stimulating hormone (TSH) levels.
Despite the lack of those differences, patients with HT had a prevalence of SIBO more than twice that of the control group, independent of gender (33% vs 15%; odds ratio, 2.71; P = .005).
When the two groups were further subdivided into two groups each — those with and without SIBO — significant further variations of microbial diversity were observed between those with and without HT, Mathur told GI & Hepatology News.
“Interestingly, we saw the small bowel microbiome was not only different in SIBO-positive patients, including higher gram negatives, which is to be expected, but that the presence or absence of hypothyroidism itself was associated with specific patterns of these gram-negative bacteria,” she explained.
“In addition, when we looked at hypothyroidism without SIBO present, there were also changes between groups, such as higher Neisseria in the hypothyroid group.”
“All these findings are novel as this is the first paper to look specifically at the small bowel,” she added, noting that previous smaller studies have focused more on evaluation of stool samples.
“We believe the small bowel is the most metabolically active area of the intestine and plays an important role in metabolism,” Mathur noted. “Thus, the microbial changes here are likely more physiologically significant than the patterns seen in stool.”
Further Findings from a Large Population
In a separate analysis, the team evaluated data from the TriNetX database on the 10-year incidence of developing SIBO among 1.1 million subjects with hypothyroidism in the US compared with 1 million controls.
They found that people with hypothyroidism were approximately twice as likely to develop SIBO compared with those without hypothyroidism (relative risk [RR], 2.20).
Furthermore, those with HT, in particular, had an even higher risk, at 2.4 times the controls (RR, 2.40).
Treatment with levothyroxine decreased the risk of developing SIBO in hypothyroidism (RR, 0.33) and HT (RR, 0.78) vs those who did not receive treatment.
Mechanisms?
However, the fact that differences in SIBO were observed even between people who were treated for HT and those without the condition in the first analysis, and hence had similar TSH levels, was notable, Mathur said.
“This suggests that perhaps there are other factors aside from TSH levels and free T4 that are at play here,” she said. “Some people have theorized that perhaps delayed gut motility in hypothyroidism promotes the development of SIBO; however, there are many other factors within this complex interplay between the microbiome and the thyroid that could also be playing a role.”
“For example, SIBO leads to inflammation and weakening of the gut barrier,” Mathur explained.
Furthermore, “levothyroxine absorption and cycling of the thyroid hormone occurs predominantly in the small bowel, [while the] microbiome plays a key role in the absorption of iron, selenium, iodine, and zinc, which are critical for thyroid function.”
Overall, “further research is needed to understand how the mechanisms are affected during the development of SIBO and hypothyroidism,” Mathur said.
Assessment of Changes Over Time Anticipated
Commenting on the research, Gregory A. Brent, MD, senior executive academic vice-chair of the Department of Medicine and professor of medicine and physiology at the David Geffen School of Medicine at University of California Los Angeles said the study is indeed novel.
“This, to my knowledge, is the first investigation to link characteristics of the small bowel microbiome with hypothyroidism,” Brent told GI & Hepatology News.
While any clinical significance has yet to be determined, “the association of these small bowel microbiome changes with hypothyroidism may have implications for contributing to the onset of autoimmune hypothyroidism in susceptible populations as well as influences on levothyroxine absorption in hypothyroid patients on levothyroxine therapy,” Brent said.
With the SIBO differences observed even among treated patients with vs without HT, “it seems less likely that the microbiome changes are the result of reduced thyroid hormone signaling,” Brent noted.
Furthermore, a key piece of the puzzle will be to observe the microbiome changes over time, he added.
“These studies were at a single time point [and] longitudinal studies will be especially important to see how the association changes over time and are influenced by the treatment of hypothyroidism and of SIBO,” Brent said.
The authors and Brent had no disclosures to report.
A version of this article appeared on Medscape.com.
More Evidence Supports ‘Individualized Approach’ to Pre-Endoscopy GLP-1 RAs
in The American Journal of Gastroenterology. Moreover, most instances occurred in patients using the drugs for type 2 diabetes (T2D) rather than for weight loss alone.
The findings suggest adopting an individualized approach rather than universal preoperative withholding of GLP-1 RAs before endoscopy, concluded Jennifer Phan, MD, medical director of the Hoag Advanced Endoscopy Center in Newport Beach, California, and colleagues. These agents are associated with slowed gastric emptying, possibly raising the risk for pulmonary aspiration. The study identified comorbid uncontrolled T2D as a risk factor for retained gastric contents.
Recommendations from gastroenterological societies and the American Society of Anesthesiologists (ASA) differ regarding pre-endoscopic holding of these ubiquitous agents used for obesity and T2D. “Many patients undergo routine endoscopic procedures, and there was concern from the anesthesia safety perspective for retained gastric contents,” Phan told GI & Hepatology News. “At first these events were seen in a handful of cases; however, out of precaution this resulted in a statement from the ASA recommending that patients hold their GLP-1 medications for at least 1 week prior to a routine endoscopic procedure.”
That guidance resulted in protocol changes within endoscopy units, cancelled procedures, and potential delays in patient care. “We wanted to study whether this concern was clinically valid and to help identify which subgroup of patients are at highest risk in order to best inform anesthesia and endoscopy practices,” Phan added.
The ASA updated its guidance in 2023.
The current study aligns with other research showing that rates of clinically relevant retained gastric contents are < 10%, Phan said. For instance, the American Gastroenterological Association (AGA) published a rapid clinical practice update in November 2023 that found insufficient evidence to support patients stopping the medications before endoscopic procedures. AGA guidance suggests an individual approach for each patient on a GLP-1 RA rather than a blanket statement on how to manage all patients taking the medications.
“Our initial hypothesis was that the rates of clinically relevant retained gastric contents in patients on GLP-1 RA medications would be low,” Phan noted. “This was born out of anecdotal experience of the limited number of aborted procedures we experienced before the ASA statement.”
Her group also hypothesized that the indication for which the GLP-1 RA was prescribed would be important, with patients taking GLP-1 RA medications for diabetes potentially having a higher likelihood of retained contents given the concomitant propensity for delayed gastric motility related to uncontrolled hyperglycemia.
The Study
The investigators identified 815 patients on confirmed GLP-1 RA medications of various types receiving endoscopy from 2021 to 2023 at four centers. Demographics, prescribing practices, and procedure outcomes were captured. GLP-1 RA management of preoperative holding was retroactively classified per ASA guidance.
Of the 815 patients (mean age, 67.7 years; 57.7% women; 53.9% White individuals), 70 (8.7%) exhibited retained gastric contents on endoscopy. Of these 65 (93%) had T2D with a median A1c of 6.5%. Among those with retained contents, most had a minimal (10, 14.3%) or moderate (31, 44.3%) amount of food retained, although 29 (41.4%) had a large quantity. Only one patient required unplanned intubation because of a large quantity of residual content, and none had aspiration events.
In multivariate analysis, the odds ratio of retention in those with diabetes was 4.1. “Given the predominance of diabetes in those with retained gastric contents, we highlight the potential to risk-stratify patients who require further preprocedural consideration,” the authors wrote.
Those with GLP-1 RA held per ASA guidance (406, 49.8%) were less likely to have retained contents (4.4% vs 12.7%; P < .001), but no significant differences for intubation (0% vs 2%; P = .53) or aborting procedure rates (28% vs 18%; P = .40) due to gastric retention were observed.
On multivariable analysis, the likelihood of food retention increased by 36% (95% CI, 1.15-1.60) for every 1% increase in glycosylated hemoglobin after adjusting for GLP-1 RA type and preoperative medication hold.
“Our study can help to differentiate which patients can be at largest risk for retained gastric contents,” Phan said, noting the impact of increasing percentages of A1C. “There’s a 36% increased likelihood of food retention in patients on GLP-1 medications, so a blanket policy to hold GLP-1s in patients who are nondiabetic and taking the medication for obesity may not be the best approach. But if patients have uncontrolled hyperglycemia, then an approach of caution is clinically valid.” In that context, holding the GLP-1 RA injection or lengthening the preoperative clear-liquid diet policy should be considered.
She noted that the study results are generalizable because the study was conducted across multiple types of hospital systems, both university and county, and included all types of GLP-1 RA.
Offering an anesthesiologist’s perspective on the study, Paul Potnuru, MD, an assistant professor in the Department of Anesthesiology, Critical Care, and Pain Medicine at UTHealth Houston and not involved in the study, called the findings “somewhat reassuring” but said the risk for aspiration was still a consideration.
A recent review, however, reported that the risk for GLP-1 RA-associated pulmonary aspiration was low.
Potnuru acknowledged that the original ASA guidance on preoperative GLP-1 RA cessation led to some confusion. “There were not a lot of data on the issue, but some studies found that even with stopping GLP-1s 2 weeks preoperatively some patients still retained gastric content,” he told GI & Hepatology News.
A study at his center recently reported that 56% of GLP-1 RA users had increased pre-anesthesia residual gastric content compared with 19% of nonusers.
From the anesthesiologist’s clinical vantage point, the margin of safety is an issue even if aspiration risk is low. “If there’s a 1 in 1000 chance or even a 1 in 3000 chance, that can be considered too high,” Potnuru said.
He further noted that the current study included only 815 patients, not nearly enough for definitive data. In addition, a retrospective study based on medical records can’t really capture all the real-world procedural changes made in the operating room. “It’s common for anesthesiologists not to document all cases of intubation, for example,” he said.
While the ideal is a completely empty stomach, he agreed that a practical alternative to stopping GLP-1 RA therapy, especially that prescribed for diabetes, would be a 24-hour liquid diet, which would clear the stomach quickly. “If you stop these drugs in patients taking them for diabetes, you get a worsening of their glycemic control,” he said.
He noted that patients have different risk tolerances, with some willing to go ahead even if ultrasound shows gastric retention, while some opt to cancel.
Prospective studies are needed, Potnuru added, “because you find more if you know what you’re looking for.” His center is starting a clinical trial in 150 patients to assess the impact of a 24-hour, liquids-only diet on gastric retention.
According to Phan, other research is following GLP-1 RA users undergoing colonoscopy. “Future studies can look at the added value of point-of-care abdominal ultrasound to see if it increases precision preoperative management in these patients on GLP-1 medications.”
Other groups are examining the safety of these agents in the general context of sedation. “It’s worth noting that the studies are being done on currently available medications and may not apply to future medications such as triple agonists or anti-amylins that may come on the market in the near future,” Phan said.
This study received no financial support. Neither the study authors nor Potnuru had any conflicts of interest.
A version of this article appeared on Medscape.com.
in The American Journal of Gastroenterology. Moreover, most instances occurred in patients using the drugs for type 2 diabetes (T2D) rather than for weight loss alone.
The findings suggest adopting an individualized approach rather than universal preoperative withholding of GLP-1 RAs before endoscopy, concluded Jennifer Phan, MD, medical director of the Hoag Advanced Endoscopy Center in Newport Beach, California, and colleagues. These agents are associated with slowed gastric emptying, possibly raising the risk for pulmonary aspiration. The study identified comorbid uncontrolled T2D as a risk factor for retained gastric contents.
Recommendations from gastroenterological societies and the American Society of Anesthesiologists (ASA) differ regarding pre-endoscopic holding of these ubiquitous agents used for obesity and T2D. “Many patients undergo routine endoscopic procedures, and there was concern from the anesthesia safety perspective for retained gastric contents,” Phan told GI & Hepatology News. “At first these events were seen in a handful of cases; however, out of precaution this resulted in a statement from the ASA recommending that patients hold their GLP-1 medications for at least 1 week prior to a routine endoscopic procedure.”
That guidance resulted in protocol changes within endoscopy units, cancelled procedures, and potential delays in patient care. “We wanted to study whether this concern was clinically valid and to help identify which subgroup of patients are at highest risk in order to best inform anesthesia and endoscopy practices,” Phan added.
The ASA updated its guidance in 2023.
The current study aligns with other research showing that rates of clinically relevant retained gastric contents are < 10%, Phan said. For instance, the American Gastroenterological Association (AGA) published a rapid clinical practice update in November 2023 that found insufficient evidence to support patients stopping the medications before endoscopic procedures. AGA guidance suggests an individual approach for each patient on a GLP-1 RA rather than a blanket statement on how to manage all patients taking the medications.
“Our initial hypothesis was that the rates of clinically relevant retained gastric contents in patients on GLP-1 RA medications would be low,” Phan noted. “This was born out of anecdotal experience of the limited number of aborted procedures we experienced before the ASA statement.”
Her group also hypothesized that the indication for which the GLP-1 RA was prescribed would be important, with patients taking GLP-1 RA medications for diabetes potentially having a higher likelihood of retained contents given the concomitant propensity for delayed gastric motility related to uncontrolled hyperglycemia.
The Study
The investigators identified 815 patients on confirmed GLP-1 RA medications of various types receiving endoscopy from 2021 to 2023 at four centers. Demographics, prescribing practices, and procedure outcomes were captured. GLP-1 RA management of preoperative holding was retroactively classified per ASA guidance.
Of the 815 patients (mean age, 67.7 years; 57.7% women; 53.9% White individuals), 70 (8.7%) exhibited retained gastric contents on endoscopy. Of these 65 (93%) had T2D with a median A1c of 6.5%. Among those with retained contents, most had a minimal (10, 14.3%) or moderate (31, 44.3%) amount of food retained, although 29 (41.4%) had a large quantity. Only one patient required unplanned intubation because of a large quantity of residual content, and none had aspiration events.
In multivariate analysis, the odds ratio of retention in those with diabetes was 4.1. “Given the predominance of diabetes in those with retained gastric contents, we highlight the potential to risk-stratify patients who require further preprocedural consideration,” the authors wrote.
Those with GLP-1 RA held per ASA guidance (406, 49.8%) were less likely to have retained contents (4.4% vs 12.7%; P < .001), but no significant differences for intubation (0% vs 2%; P = .53) or aborting procedure rates (28% vs 18%; P = .40) due to gastric retention were observed.
On multivariable analysis, the likelihood of food retention increased by 36% (95% CI, 1.15-1.60) for every 1% increase in glycosylated hemoglobin after adjusting for GLP-1 RA type and preoperative medication hold.
“Our study can help to differentiate which patients can be at largest risk for retained gastric contents,” Phan said, noting the impact of increasing percentages of A1C. “There’s a 36% increased likelihood of food retention in patients on GLP-1 medications, so a blanket policy to hold GLP-1s in patients who are nondiabetic and taking the medication for obesity may not be the best approach. But if patients have uncontrolled hyperglycemia, then an approach of caution is clinically valid.” In that context, holding the GLP-1 RA injection or lengthening the preoperative clear-liquid diet policy should be considered.
She noted that the study results are generalizable because the study was conducted across multiple types of hospital systems, both university and county, and included all types of GLP-1 RA.
Offering an anesthesiologist’s perspective on the study, Paul Potnuru, MD, an assistant professor in the Department of Anesthesiology, Critical Care, and Pain Medicine at UTHealth Houston and not involved in the study, called the findings “somewhat reassuring” but said the risk for aspiration was still a consideration.
A recent review, however, reported that the risk for GLP-1 RA-associated pulmonary aspiration was low.
Potnuru acknowledged that the original ASA guidance on preoperative GLP-1 RA cessation led to some confusion. “There were not a lot of data on the issue, but some studies found that even with stopping GLP-1s 2 weeks preoperatively some patients still retained gastric content,” he told GI & Hepatology News.
A study at his center recently reported that 56% of GLP-1 RA users had increased pre-anesthesia residual gastric content compared with 19% of nonusers.
From the anesthesiologist’s clinical vantage point, the margin of safety is an issue even if aspiration risk is low. “If there’s a 1 in 1000 chance or even a 1 in 3000 chance, that can be considered too high,” Potnuru said.
He further noted that the current study included only 815 patients, not nearly enough for definitive data. In addition, a retrospective study based on medical records can’t really capture all the real-world procedural changes made in the operating room. “It’s common for anesthesiologists not to document all cases of intubation, for example,” he said.
While the ideal is a completely empty stomach, he agreed that a practical alternative to stopping GLP-1 RA therapy, especially that prescribed for diabetes, would be a 24-hour liquid diet, which would clear the stomach quickly. “If you stop these drugs in patients taking them for diabetes, you get a worsening of their glycemic control,” he said.
He noted that patients have different risk tolerances, with some willing to go ahead even if ultrasound shows gastric retention, while some opt to cancel.
Prospective studies are needed, Potnuru added, “because you find more if you know what you’re looking for.” His center is starting a clinical trial in 150 patients to assess the impact of a 24-hour, liquids-only diet on gastric retention.
According to Phan, other research is following GLP-1 RA users undergoing colonoscopy. “Future studies can look at the added value of point-of-care abdominal ultrasound to see if it increases precision preoperative management in these patients on GLP-1 medications.”
Other groups are examining the safety of these agents in the general context of sedation. “It’s worth noting that the studies are being done on currently available medications and may not apply to future medications such as triple agonists or anti-amylins that may come on the market in the near future,” Phan said.
This study received no financial support. Neither the study authors nor Potnuru had any conflicts of interest.
A version of this article appeared on Medscape.com.
in The American Journal of Gastroenterology. Moreover, most instances occurred in patients using the drugs for type 2 diabetes (T2D) rather than for weight loss alone.
The findings suggest adopting an individualized approach rather than universal preoperative withholding of GLP-1 RAs before endoscopy, concluded Jennifer Phan, MD, medical director of the Hoag Advanced Endoscopy Center in Newport Beach, California, and colleagues. These agents are associated with slowed gastric emptying, possibly raising the risk for pulmonary aspiration. The study identified comorbid uncontrolled T2D as a risk factor for retained gastric contents.
Recommendations from gastroenterological societies and the American Society of Anesthesiologists (ASA) differ regarding pre-endoscopic holding of these ubiquitous agents used for obesity and T2D. “Many patients undergo routine endoscopic procedures, and there was concern from the anesthesia safety perspective for retained gastric contents,” Phan told GI & Hepatology News. “At first these events were seen in a handful of cases; however, out of precaution this resulted in a statement from the ASA recommending that patients hold their GLP-1 medications for at least 1 week prior to a routine endoscopic procedure.”
That guidance resulted in protocol changes within endoscopy units, cancelled procedures, and potential delays in patient care. “We wanted to study whether this concern was clinically valid and to help identify which subgroup of patients are at highest risk in order to best inform anesthesia and endoscopy practices,” Phan added.
The ASA updated its guidance in 2023.
The current study aligns with other research showing that rates of clinically relevant retained gastric contents are < 10%, Phan said. For instance, the American Gastroenterological Association (AGA) published a rapid clinical practice update in November 2023 that found insufficient evidence to support patients stopping the medications before endoscopic procedures. AGA guidance suggests an individual approach for each patient on a GLP-1 RA rather than a blanket statement on how to manage all patients taking the medications.
“Our initial hypothesis was that the rates of clinically relevant retained gastric contents in patients on GLP-1 RA medications would be low,” Phan noted. “This was born out of anecdotal experience of the limited number of aborted procedures we experienced before the ASA statement.”
Her group also hypothesized that the indication for which the GLP-1 RA was prescribed would be important, with patients taking GLP-1 RA medications for diabetes potentially having a higher likelihood of retained contents given the concomitant propensity for delayed gastric motility related to uncontrolled hyperglycemia.
The Study
The investigators identified 815 patients on confirmed GLP-1 RA medications of various types receiving endoscopy from 2021 to 2023 at four centers. Demographics, prescribing practices, and procedure outcomes were captured. GLP-1 RA management of preoperative holding was retroactively classified per ASA guidance.
Of the 815 patients (mean age, 67.7 years; 57.7% women; 53.9% White individuals), 70 (8.7%) exhibited retained gastric contents on endoscopy. Of these 65 (93%) had T2D with a median A1c of 6.5%. Among those with retained contents, most had a minimal (10, 14.3%) or moderate (31, 44.3%) amount of food retained, although 29 (41.4%) had a large quantity. Only one patient required unplanned intubation because of a large quantity of residual content, and none had aspiration events.
In multivariate analysis, the odds ratio of retention in those with diabetes was 4.1. “Given the predominance of diabetes in those with retained gastric contents, we highlight the potential to risk-stratify patients who require further preprocedural consideration,” the authors wrote.
Those with GLP-1 RA held per ASA guidance (406, 49.8%) were less likely to have retained contents (4.4% vs 12.7%; P < .001), but no significant differences for intubation (0% vs 2%; P = .53) or aborting procedure rates (28% vs 18%; P = .40) due to gastric retention were observed.
On multivariable analysis, the likelihood of food retention increased by 36% (95% CI, 1.15-1.60) for every 1% increase in glycosylated hemoglobin after adjusting for GLP-1 RA type and preoperative medication hold.
“Our study can help to differentiate which patients can be at largest risk for retained gastric contents,” Phan said, noting the impact of increasing percentages of A1C. “There’s a 36% increased likelihood of food retention in patients on GLP-1 medications, so a blanket policy to hold GLP-1s in patients who are nondiabetic and taking the medication for obesity may not be the best approach. But if patients have uncontrolled hyperglycemia, then an approach of caution is clinically valid.” In that context, holding the GLP-1 RA injection or lengthening the preoperative clear-liquid diet policy should be considered.
She noted that the study results are generalizable because the study was conducted across multiple types of hospital systems, both university and county, and included all types of GLP-1 RA.
Offering an anesthesiologist’s perspective on the study, Paul Potnuru, MD, an assistant professor in the Department of Anesthesiology, Critical Care, and Pain Medicine at UTHealth Houston and not involved in the study, called the findings “somewhat reassuring” but said the risk for aspiration was still a consideration.
A recent review, however, reported that the risk for GLP-1 RA-associated pulmonary aspiration was low.
Potnuru acknowledged that the original ASA guidance on preoperative GLP-1 RA cessation led to some confusion. “There were not a lot of data on the issue, but some studies found that even with stopping GLP-1s 2 weeks preoperatively some patients still retained gastric content,” he told GI & Hepatology News.
A study at his center recently reported that 56% of GLP-1 RA users had increased pre-anesthesia residual gastric content compared with 19% of nonusers.
From the anesthesiologist’s clinical vantage point, the margin of safety is an issue even if aspiration risk is low. “If there’s a 1 in 1000 chance or even a 1 in 3000 chance, that can be considered too high,” Potnuru said.
He further noted that the current study included only 815 patients, not nearly enough for definitive data. In addition, a retrospective study based on medical records can’t really capture all the real-world procedural changes made in the operating room. “It’s common for anesthesiologists not to document all cases of intubation, for example,” he said.
While the ideal is a completely empty stomach, he agreed that a practical alternative to stopping GLP-1 RA therapy, especially that prescribed for diabetes, would be a 24-hour liquid diet, which would clear the stomach quickly. “If you stop these drugs in patients taking them for diabetes, you get a worsening of their glycemic control,” he said.
He noted that patients have different risk tolerances, with some willing to go ahead even if ultrasound shows gastric retention, while some opt to cancel.
Prospective studies are needed, Potnuru added, “because you find more if you know what you’re looking for.” His center is starting a clinical trial in 150 patients to assess the impact of a 24-hour, liquids-only diet on gastric retention.
According to Phan, other research is following GLP-1 RA users undergoing colonoscopy. “Future studies can look at the added value of point-of-care abdominal ultrasound to see if it increases precision preoperative management in these patients on GLP-1 medications.”
Other groups are examining the safety of these agents in the general context of sedation. “It’s worth noting that the studies are being done on currently available medications and may not apply to future medications such as triple agonists or anti-amylins that may come on the market in the near future,” Phan said.
This study received no financial support. Neither the study authors nor Potnuru had any conflicts of interest.
A version of this article appeared on Medscape.com.
You Are When You Eat: Microbiome Rhythm and Metabolic Health
Similar to circadian rhythms that help regulate when we naturally fall asleep and wake up, microbial rhythms in our gut are naturally active at certain times of the day to help regulate our digestion.
Investigators from the University of California, San Diego sought out to track these microbial rhythms to determine whether aligning the times we eat to when our gut microbes are most active – time-restricted feeding (TRF) – can bolster our metabolic health. Their research was published recently in Cell Host & Microbe.
“Microbial rhythms are daily fluctuations in the composition and function of microbes living in our gut. Much like how our bodies follow an internal clock (circadian rhythm), gut microbes also have their own rhythms, adjusting their activities based on the time of day and when we eat,” said Amir Zarrinpar, MD, PhD, a gastroenterologist at UC San Diego School of Medicine, and senior author of the study.
Zarrinpar and his team were particularly interested in observing whether adopting the TRF approach counteracted the harmful metabolic effects often associated with consuming a high-fat diet.
The study is also notable for the team’s use of technology able to observe real-time microbial changes in the gut — something not previously attainable with existing metagenomics.
How the Study Evolved With New Tech
Researchers separated three groups of mice to analyze their microbiome activity: one on a high-fat diet with unrestricted access, another on the same high-fat diet within a TRF window of 8 hours per day, and a control group on a normal chow diet with unrestricted access.
“In mice, [their] microbial rhythms are well-aligned with their nocturnal lifestyle. For example, during their active (nighttime) period, certain beneficial microbial activities increase, helping digest food, absorb nutrients, and regulate metabolism,” said Zarrinpar. As a result, the team made sure the mice’s TRF window was at night or when they would normally be awake.
“We chose an 8-hour feeding window based on earlier research showing this time period allows mice to consume the same total calories as those with unlimited food access,” said Zarrinpar. “By controlling [the] calories in this way, we ensure any metabolic or microbial benefits we observe are specifically due to the timing of eating, rather than differences in total food intake.”
But before any observations could be made, the team first needed a way to see real-time changes in the animals’ gut microbiomes.
Zarrinpar and his team were able to uncover this, thanks to metatranscriptomics, a technique used to capture real-time microbial activity by profiling RNA transcripts. Compared with the more traditional technique of metagenomics, which could only be used to identify which genes were present, metatranscriptomics provided more in-depth temporal and activity-related context, allowing the team to observe dynamic microbial changes.
“[Metatranscriptomics] helps us understand not just which microbes are present, but specifically what they are doing at any given moment,” said Zarrinpar. “In contrast, metagenomics looks only at microbial DNA, which provides information about what microbes are potentially capable of doing, but doesn’t tell us if those genes are actively expressed. By comparing microbial gene expression (using metatranscriptomics) and microbial gene abundance (using metagenomics) across different diet and feeding conditions in [light and dark] phases, we aimed to identify how feeding timing might influence microbial activity.”
Because metagenomics focuses on stable genetic material, this technique cannot capture the real-time microbial responses to dietary timing presented in rapidly changing, short-lived RNA. At the same time, the instability of the RNA makes it difficult to test hypotheses experimentally and explains why researchers haven’t more widely relied on metatranscriptomics.
To overcome this difficulty, Zarrinpar and his team had to wait to take advantage of improved bioinformatics tools to simplify their analysis of complex datasets. “It took several years for us to analyze this dataset because robust computational tools for metatranscriptomic analysis were not widely available when we initially collected our samples. Additionally, sequencing costs were very high. To clearly identify microbial activity, we needed deep sequencing coverage to distinguish species-level differences in gene expression, especially for genes that are common across multiple types of microbes,” said Zarrinpar.
What They Found
After monitoring these groups of mice for 8 weeks, the results were revealed.
As predicted, “When mice have free access to a high-fat diet, their normal eating behavior changes significantly. Instead of limiting their activity and feeding to their active nighttime period, these mice begin to stay awake and eat during the day, which is their typical rest phase,” Zarrinpar explained.
“This unusual daytime activity interferes with important physiological processes. Consequently, the animals experience circadian misalignment, a condition similar to what human shift workers experience when their sleep-wake and eating cycles don’t match their internal biological clocks,” he continued. “This misalignment can negatively affect metabolism, immunity, and overall health, potentially leading to metabolic diseases.”
For the mice that consumed a high-fat diet within a TRF window, metabolic phenotyping demonstrated that their specific diet regimen had protected them from harmful high-fat induced effects including adiposity, inflammation, and insulin resistance.
Even more promising, the mice not only were protected from metabolic disruption but also experienced physiological improvements including glucose homeostasis and the partial restoration of the daily microbial rhythms absent in the mice with unrestricted access to a high-fat diet.
While the TRF approach did not fully restore the normal, healthy rhythmicity seen in the control mice, the researchers noted distinct shifts in microbial patterns that indicated time-dependent enrichment in genes attributed to lipid and carbohydrate metabolism.
Better Metabolic Health — and Better Tools for Researching It
Thankfully, the latest advancements in sequencing technology, including long-read sequencing methods, are making metatranscriptomics easier for research. “These newer platforms offer greater resolution at a lower cost, making metatranscriptomics increasingly accessible,” said Zarrinpar. With these emerging technologies, he believes metatranscriptomics will become a more standard, widely used method for researchers to better understand the influence of microbial activity on our health.
These tools, for example, enabled Zarrinpar and the team to delve deeper and focus on the transcription of a particular enzyme they identified as a pivotal influence in observable metabolic improvements: bile salt hydrolase (BSH), known to regulate lipid and glucose metabolism. The TRF approach notably enhanced the expression of the BSH gene during the daytime in the gut microbe Dubosiella newyorkensis, which has a functional human equivalent.
To determine why this happened, the team leveraged genetic engineering to insert several active BSH gene variants into a benign strain of gut bacteria to administer to the mice. The only variant to produce metabolic improvements was the one derived from Dubosiella newyorkensis; the mice who were given this BSH-expressing engineered native bacteria (ENB) had increased lean muscle mass, less body fat, lower insulin levels, enhanced insulin sensitivity, and better blood glucose regulation.
“It is still early to know the full clinical potential of this new BSH-expressing engineered native bacterium,” said Zarrinpar. “However, our long-term goal is to develop a therapeutic that can be administered as a single dose, stably colonize the gut, and provide long-lasting metabolic benefits.” Testing the engineered bacteria in obese and diabetic mice on a high-fat diet would be a next step to determine whether its potential indeed holds up. If proven successful, it could then be used to develop future targeted therapies and interventions to treat common metabolic disorders.
With this engineered bacteria, Zarrinpar and his team are hopeful that it alone can replicate the microbial benefits associated with following a TRF dietary schedule. “In our study, the engineered bacterium continuously expressed the enzyme DnBSH1, independently of dietary or environmental factors. As a result, the bacterium provided metabolic benefits similar to those seen with TRF, even without requiring the mice to strictly adhere to a TRF schedule,” said Zarrinpar.
“This suggests the exciting possibility that this engineered microbe might serve either as a replacement for TRF or as a way to enhance its beneficial effects,” he continued. “Further studies will help determine whether combining this ENB with TRF could provide additional or synergistic improvements in metabolic health.”
Looking Ahead
“As the pioneer of the single anastomosis duodenal switch which separates bile from food until halfway down the GI tract, I agree that bile is very important in controlling metabolism and glucose,” said Mitchell Roslin, MD, chief director of bariatric and metabolic surgery at Lenox Hill Hospital, and the Donald and Barbara Zucker School of Medicine, Hempstead, New York, who was not involved in the study. “Using enzymes or medications that work in the GI tract without absorption into the body is very interesting and has great potential. It is an early but exciting prospect.”
However, Roslin expressed some reservations. “I think we are still trying to understand whether the difference in microbiomes is the cause or effect/association. Is the microbiome the difference or is a different microbiome representative of a diet that has more fiber and less processed foods? Thus, while I find this academically fascinating, I think that there are very basic questions that need better answers, before we look at the transcription of bacteria.”
Furthermore, translating the metabolic results observed in mice to humans might not be as straightforward. “Small animal research is mandatory, but how the findings convert to humans is highly speculative,” said Roslin. “Mice that are studied are usually bred for medical research, with reduced genetic variation. Many animal models are more sensitive to time-restricted eating and caloric restriction than humans.”
While it requires further research and validation, this UC San Diego study nevertheless contributes to our overall understanding of host-microbe interactions. “We demonstrate that host circadian rhythms significantly influence microbial function, and conversely, these microbial functions can directly impact host metabolism,” said Zarrinpar. “Importantly, we now have a method to test how specific microbial activities affect host physiology by engineering native gut bacteria.”
Roslin similarly emphasized the importance of continued investment in exploring the microbial ecosystem inside us all. “There is wider evidence that bacteria and microbes are not just passengers using us for a ride but perhaps manipulating every action we take.”
A version of this article appeared on Medscape.com.
Similar to circadian rhythms that help regulate when we naturally fall asleep and wake up, microbial rhythms in our gut are naturally active at certain times of the day to help regulate our digestion.
Investigators from the University of California, San Diego sought out to track these microbial rhythms to determine whether aligning the times we eat to when our gut microbes are most active – time-restricted feeding (TRF) – can bolster our metabolic health. Their research was published recently in Cell Host & Microbe.
“Microbial rhythms are daily fluctuations in the composition and function of microbes living in our gut. Much like how our bodies follow an internal clock (circadian rhythm), gut microbes also have their own rhythms, adjusting their activities based on the time of day and when we eat,” said Amir Zarrinpar, MD, PhD, a gastroenterologist at UC San Diego School of Medicine, and senior author of the study.
Zarrinpar and his team were particularly interested in observing whether adopting the TRF approach counteracted the harmful metabolic effects often associated with consuming a high-fat diet.
The study is also notable for the team’s use of technology able to observe real-time microbial changes in the gut — something not previously attainable with existing metagenomics.
How the Study Evolved With New Tech
Researchers separated three groups of mice to analyze their microbiome activity: one on a high-fat diet with unrestricted access, another on the same high-fat diet within a TRF window of 8 hours per day, and a control group on a normal chow diet with unrestricted access.
“In mice, [their] microbial rhythms are well-aligned with their nocturnal lifestyle. For example, during their active (nighttime) period, certain beneficial microbial activities increase, helping digest food, absorb nutrients, and regulate metabolism,” said Zarrinpar. As a result, the team made sure the mice’s TRF window was at night or when they would normally be awake.
“We chose an 8-hour feeding window based on earlier research showing this time period allows mice to consume the same total calories as those with unlimited food access,” said Zarrinpar. “By controlling [the] calories in this way, we ensure any metabolic or microbial benefits we observe are specifically due to the timing of eating, rather than differences in total food intake.”
But before any observations could be made, the team first needed a way to see real-time changes in the animals’ gut microbiomes.
Zarrinpar and his team were able to uncover this, thanks to metatranscriptomics, a technique used to capture real-time microbial activity by profiling RNA transcripts. Compared with the more traditional technique of metagenomics, which could only be used to identify which genes were present, metatranscriptomics provided more in-depth temporal and activity-related context, allowing the team to observe dynamic microbial changes.
“[Metatranscriptomics] helps us understand not just which microbes are present, but specifically what they are doing at any given moment,” said Zarrinpar. “In contrast, metagenomics looks only at microbial DNA, which provides information about what microbes are potentially capable of doing, but doesn’t tell us if those genes are actively expressed. By comparing microbial gene expression (using metatranscriptomics) and microbial gene abundance (using metagenomics) across different diet and feeding conditions in [light and dark] phases, we aimed to identify how feeding timing might influence microbial activity.”
Because metagenomics focuses on stable genetic material, this technique cannot capture the real-time microbial responses to dietary timing presented in rapidly changing, short-lived RNA. At the same time, the instability of the RNA makes it difficult to test hypotheses experimentally and explains why researchers haven’t more widely relied on metatranscriptomics.
To overcome this difficulty, Zarrinpar and his team had to wait to take advantage of improved bioinformatics tools to simplify their analysis of complex datasets. “It took several years for us to analyze this dataset because robust computational tools for metatranscriptomic analysis were not widely available when we initially collected our samples. Additionally, sequencing costs were very high. To clearly identify microbial activity, we needed deep sequencing coverage to distinguish species-level differences in gene expression, especially for genes that are common across multiple types of microbes,” said Zarrinpar.
What They Found
After monitoring these groups of mice for 8 weeks, the results were revealed.
As predicted, “When mice have free access to a high-fat diet, their normal eating behavior changes significantly. Instead of limiting their activity and feeding to their active nighttime period, these mice begin to stay awake and eat during the day, which is their typical rest phase,” Zarrinpar explained.
“This unusual daytime activity interferes with important physiological processes. Consequently, the animals experience circadian misalignment, a condition similar to what human shift workers experience when their sleep-wake and eating cycles don’t match their internal biological clocks,” he continued. “This misalignment can negatively affect metabolism, immunity, and overall health, potentially leading to metabolic diseases.”
For the mice that consumed a high-fat diet within a TRF window, metabolic phenotyping demonstrated that their specific diet regimen had protected them from harmful high-fat induced effects including adiposity, inflammation, and insulin resistance.
Even more promising, the mice not only were protected from metabolic disruption but also experienced physiological improvements including glucose homeostasis and the partial restoration of the daily microbial rhythms absent in the mice with unrestricted access to a high-fat diet.
While the TRF approach did not fully restore the normal, healthy rhythmicity seen in the control mice, the researchers noted distinct shifts in microbial patterns that indicated time-dependent enrichment in genes attributed to lipid and carbohydrate metabolism.
Better Metabolic Health — and Better Tools for Researching It
Thankfully, the latest advancements in sequencing technology, including long-read sequencing methods, are making metatranscriptomics easier for research. “These newer platforms offer greater resolution at a lower cost, making metatranscriptomics increasingly accessible,” said Zarrinpar. With these emerging technologies, he believes metatranscriptomics will become a more standard, widely used method for researchers to better understand the influence of microbial activity on our health.
These tools, for example, enabled Zarrinpar and the team to delve deeper and focus on the transcription of a particular enzyme they identified as a pivotal influence in observable metabolic improvements: bile salt hydrolase (BSH), known to regulate lipid and glucose metabolism. The TRF approach notably enhanced the expression of the BSH gene during the daytime in the gut microbe Dubosiella newyorkensis, which has a functional human equivalent.
To determine why this happened, the team leveraged genetic engineering to insert several active BSH gene variants into a benign strain of gut bacteria to administer to the mice. The only variant to produce metabolic improvements was the one derived from Dubosiella newyorkensis; the mice who were given this BSH-expressing engineered native bacteria (ENB) had increased lean muscle mass, less body fat, lower insulin levels, enhanced insulin sensitivity, and better blood glucose regulation.
“It is still early to know the full clinical potential of this new BSH-expressing engineered native bacterium,” said Zarrinpar. “However, our long-term goal is to develop a therapeutic that can be administered as a single dose, stably colonize the gut, and provide long-lasting metabolic benefits.” Testing the engineered bacteria in obese and diabetic mice on a high-fat diet would be a next step to determine whether its potential indeed holds up. If proven successful, it could then be used to develop future targeted therapies and interventions to treat common metabolic disorders.
With this engineered bacteria, Zarrinpar and his team are hopeful that it alone can replicate the microbial benefits associated with following a TRF dietary schedule. “In our study, the engineered bacterium continuously expressed the enzyme DnBSH1, independently of dietary or environmental factors. As a result, the bacterium provided metabolic benefits similar to those seen with TRF, even without requiring the mice to strictly adhere to a TRF schedule,” said Zarrinpar.
“This suggests the exciting possibility that this engineered microbe might serve either as a replacement for TRF or as a way to enhance its beneficial effects,” he continued. “Further studies will help determine whether combining this ENB with TRF could provide additional or synergistic improvements in metabolic health.”
Looking Ahead
“As the pioneer of the single anastomosis duodenal switch which separates bile from food until halfway down the GI tract, I agree that bile is very important in controlling metabolism and glucose,” said Mitchell Roslin, MD, chief director of bariatric and metabolic surgery at Lenox Hill Hospital, and the Donald and Barbara Zucker School of Medicine, Hempstead, New York, who was not involved in the study. “Using enzymes or medications that work in the GI tract without absorption into the body is very interesting and has great potential. It is an early but exciting prospect.”
However, Roslin expressed some reservations. “I think we are still trying to understand whether the difference in microbiomes is the cause or effect/association. Is the microbiome the difference or is a different microbiome representative of a diet that has more fiber and less processed foods? Thus, while I find this academically fascinating, I think that there are very basic questions that need better answers, before we look at the transcription of bacteria.”
Furthermore, translating the metabolic results observed in mice to humans might not be as straightforward. “Small animal research is mandatory, but how the findings convert to humans is highly speculative,” said Roslin. “Mice that are studied are usually bred for medical research, with reduced genetic variation. Many animal models are more sensitive to time-restricted eating and caloric restriction than humans.”
While it requires further research and validation, this UC San Diego study nevertheless contributes to our overall understanding of host-microbe interactions. “We demonstrate that host circadian rhythms significantly influence microbial function, and conversely, these microbial functions can directly impact host metabolism,” said Zarrinpar. “Importantly, we now have a method to test how specific microbial activities affect host physiology by engineering native gut bacteria.”
Roslin similarly emphasized the importance of continued investment in exploring the microbial ecosystem inside us all. “There is wider evidence that bacteria and microbes are not just passengers using us for a ride but perhaps manipulating every action we take.”
A version of this article appeared on Medscape.com.
Similar to circadian rhythms that help regulate when we naturally fall asleep and wake up, microbial rhythms in our gut are naturally active at certain times of the day to help regulate our digestion.
Investigators from the University of California, San Diego sought out to track these microbial rhythms to determine whether aligning the times we eat to when our gut microbes are most active – time-restricted feeding (TRF) – can bolster our metabolic health. Their research was published recently in Cell Host & Microbe.
“Microbial rhythms are daily fluctuations in the composition and function of microbes living in our gut. Much like how our bodies follow an internal clock (circadian rhythm), gut microbes also have their own rhythms, adjusting their activities based on the time of day and when we eat,” said Amir Zarrinpar, MD, PhD, a gastroenterologist at UC San Diego School of Medicine, and senior author of the study.
Zarrinpar and his team were particularly interested in observing whether adopting the TRF approach counteracted the harmful metabolic effects often associated with consuming a high-fat diet.
The study is also notable for the team’s use of technology able to observe real-time microbial changes in the gut — something not previously attainable with existing metagenomics.
How the Study Evolved With New Tech
Researchers separated three groups of mice to analyze their microbiome activity: one on a high-fat diet with unrestricted access, another on the same high-fat diet within a TRF window of 8 hours per day, and a control group on a normal chow diet with unrestricted access.
“In mice, [their] microbial rhythms are well-aligned with their nocturnal lifestyle. For example, during their active (nighttime) period, certain beneficial microbial activities increase, helping digest food, absorb nutrients, and regulate metabolism,” said Zarrinpar. As a result, the team made sure the mice’s TRF window was at night or when they would normally be awake.
“We chose an 8-hour feeding window based on earlier research showing this time period allows mice to consume the same total calories as those with unlimited food access,” said Zarrinpar. “By controlling [the] calories in this way, we ensure any metabolic or microbial benefits we observe are specifically due to the timing of eating, rather than differences in total food intake.”
But before any observations could be made, the team first needed a way to see real-time changes in the animals’ gut microbiomes.
Zarrinpar and his team were able to uncover this, thanks to metatranscriptomics, a technique used to capture real-time microbial activity by profiling RNA transcripts. Compared with the more traditional technique of metagenomics, which could only be used to identify which genes were present, metatranscriptomics provided more in-depth temporal and activity-related context, allowing the team to observe dynamic microbial changes.
“[Metatranscriptomics] helps us understand not just which microbes are present, but specifically what they are doing at any given moment,” said Zarrinpar. “In contrast, metagenomics looks only at microbial DNA, which provides information about what microbes are potentially capable of doing, but doesn’t tell us if those genes are actively expressed. By comparing microbial gene expression (using metatranscriptomics) and microbial gene abundance (using metagenomics) across different diet and feeding conditions in [light and dark] phases, we aimed to identify how feeding timing might influence microbial activity.”
Because metagenomics focuses on stable genetic material, this technique cannot capture the real-time microbial responses to dietary timing presented in rapidly changing, short-lived RNA. At the same time, the instability of the RNA makes it difficult to test hypotheses experimentally and explains why researchers haven’t more widely relied on metatranscriptomics.
To overcome this difficulty, Zarrinpar and his team had to wait to take advantage of improved bioinformatics tools to simplify their analysis of complex datasets. “It took several years for us to analyze this dataset because robust computational tools for metatranscriptomic analysis were not widely available when we initially collected our samples. Additionally, sequencing costs were very high. To clearly identify microbial activity, we needed deep sequencing coverage to distinguish species-level differences in gene expression, especially for genes that are common across multiple types of microbes,” said Zarrinpar.
What They Found
After monitoring these groups of mice for 8 weeks, the results were revealed.
As predicted, “When mice have free access to a high-fat diet, their normal eating behavior changes significantly. Instead of limiting their activity and feeding to their active nighttime period, these mice begin to stay awake and eat during the day, which is their typical rest phase,” Zarrinpar explained.
“This unusual daytime activity interferes with important physiological processes. Consequently, the animals experience circadian misalignment, a condition similar to what human shift workers experience when their sleep-wake and eating cycles don’t match their internal biological clocks,” he continued. “This misalignment can negatively affect metabolism, immunity, and overall health, potentially leading to metabolic diseases.”
For the mice that consumed a high-fat diet within a TRF window, metabolic phenotyping demonstrated that their specific diet regimen had protected them from harmful high-fat induced effects including adiposity, inflammation, and insulin resistance.
Even more promising, the mice not only were protected from metabolic disruption but also experienced physiological improvements including glucose homeostasis and the partial restoration of the daily microbial rhythms absent in the mice with unrestricted access to a high-fat diet.
While the TRF approach did not fully restore the normal, healthy rhythmicity seen in the control mice, the researchers noted distinct shifts in microbial patterns that indicated time-dependent enrichment in genes attributed to lipid and carbohydrate metabolism.
Better Metabolic Health — and Better Tools for Researching It
Thankfully, the latest advancements in sequencing technology, including long-read sequencing methods, are making metatranscriptomics easier for research. “These newer platforms offer greater resolution at a lower cost, making metatranscriptomics increasingly accessible,” said Zarrinpar. With these emerging technologies, he believes metatranscriptomics will become a more standard, widely used method for researchers to better understand the influence of microbial activity on our health.
These tools, for example, enabled Zarrinpar and the team to delve deeper and focus on the transcription of a particular enzyme they identified as a pivotal influence in observable metabolic improvements: bile salt hydrolase (BSH), known to regulate lipid and glucose metabolism. The TRF approach notably enhanced the expression of the BSH gene during the daytime in the gut microbe Dubosiella newyorkensis, which has a functional human equivalent.
To determine why this happened, the team leveraged genetic engineering to insert several active BSH gene variants into a benign strain of gut bacteria to administer to the mice. The only variant to produce metabolic improvements was the one derived from Dubosiella newyorkensis; the mice who were given this BSH-expressing engineered native bacteria (ENB) had increased lean muscle mass, less body fat, lower insulin levels, enhanced insulin sensitivity, and better blood glucose regulation.
“It is still early to know the full clinical potential of this new BSH-expressing engineered native bacterium,” said Zarrinpar. “However, our long-term goal is to develop a therapeutic that can be administered as a single dose, stably colonize the gut, and provide long-lasting metabolic benefits.” Testing the engineered bacteria in obese and diabetic mice on a high-fat diet would be a next step to determine whether its potential indeed holds up. If proven successful, it could then be used to develop future targeted therapies and interventions to treat common metabolic disorders.
With this engineered bacteria, Zarrinpar and his team are hopeful that it alone can replicate the microbial benefits associated with following a TRF dietary schedule. “In our study, the engineered bacterium continuously expressed the enzyme DnBSH1, independently of dietary or environmental factors. As a result, the bacterium provided metabolic benefits similar to those seen with TRF, even without requiring the mice to strictly adhere to a TRF schedule,” said Zarrinpar.
“This suggests the exciting possibility that this engineered microbe might serve either as a replacement for TRF or as a way to enhance its beneficial effects,” he continued. “Further studies will help determine whether combining this ENB with TRF could provide additional or synergistic improvements in metabolic health.”
Looking Ahead
“As the pioneer of the single anastomosis duodenal switch which separates bile from food until halfway down the GI tract, I agree that bile is very important in controlling metabolism and glucose,” said Mitchell Roslin, MD, chief director of bariatric and metabolic surgery at Lenox Hill Hospital, and the Donald and Barbara Zucker School of Medicine, Hempstead, New York, who was not involved in the study. “Using enzymes or medications that work in the GI tract without absorption into the body is very interesting and has great potential. It is an early but exciting prospect.”
However, Roslin expressed some reservations. “I think we are still trying to understand whether the difference in microbiomes is the cause or effect/association. Is the microbiome the difference or is a different microbiome representative of a diet that has more fiber and less processed foods? Thus, while I find this academically fascinating, I think that there are very basic questions that need better answers, before we look at the transcription of bacteria.”
Furthermore, translating the metabolic results observed in mice to humans might not be as straightforward. “Small animal research is mandatory, but how the findings convert to humans is highly speculative,” said Roslin. “Mice that are studied are usually bred for medical research, with reduced genetic variation. Many animal models are more sensitive to time-restricted eating and caloric restriction than humans.”
While it requires further research and validation, this UC San Diego study nevertheless contributes to our overall understanding of host-microbe interactions. “We demonstrate that host circadian rhythms significantly influence microbial function, and conversely, these microbial functions can directly impact host metabolism,” said Zarrinpar. “Importantly, we now have a method to test how specific microbial activities affect host physiology by engineering native gut bacteria.”
Roslin similarly emphasized the importance of continued investment in exploring the microbial ecosystem inside us all. “There is wider evidence that bacteria and microbes are not just passengers using us for a ride but perhaps manipulating every action we take.”
A version of this article appeared on Medscape.com.
Eradicating H Pylori Cuts Long-Term Gastric Cancer Risk
Helicobacter pylori (HP) eradication reduced the risk of gastric noncardia adenocarcinoma in five Scandinavian countries, a population-based study in Gastroenterology reported. Risk became virtually similar to the background population from 11 years after treatment onward.
HP infection of the stomach is the main established risk factor for this tumor, but not much was known about the impact of eradication on long-term risk, particularly in Western populations, noted investigators led by Jesper Lagengren, MD, a gastrointestinal surgeon and professor at the Karolinksa Institutet in Stockholm, Sweden. Research with longer follow-up has reported contradictory results.
The study cohort included all adults treated for HP from 1995 to 2019 in Denmark, Finland, Iceland, Norway, and Sweden. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were calculated by comparing the gastric noncardia adenocarcinoma incidence in the study cohort with the incidence in the background population of the same age, sex, calendar period, and country.
The 659,592 treated participants were 54.3% women, 61.5% age 50 or younger, and had no serious comorbidities. They contributed to 5,480,873 person-years at risk with a mean follow-up of 8.3 years. Treatment consisted of a minimum one-week antibiotic regimen with two of amoxicillin, clarithromycin, or metronidazole, in combination with a proton pump inhibitor. This is the recommended regimen in the Nordic countries, where it achieves successful eradication in 90% of infected individuals.
Among these patients, 1311 developed gastric noncardia adenocarcinoma. Over as many as 24 years of follow-up, the SIR in treated HP patients was initially significantly higher than in the background population at 2.27 (95% confidence interval [CI], 2.10-2.44) at 1 to 5 years after treatment. By 6 to 10 years the SIR had dropped to 1.34 (1.21-1.48) and by 11 to 24 years it further fell to 1.11 (.98-1.27). In terms of observed vs expected cases, that translated to 702 vs 310 at 1 to 5 years, 374 vs 270 at 6 to 10 years, and 235 vs 211 from 11 to 24 years.
The results of the Nordic study align with systematic reviews from Asian populations indicating that eradication reduces the risk of gastric cancer, the authors said.
They noted gastric HP infection is the most prevalent bacterial infection worldwide, found in approximately 50% of the global population but with striking geographical variations in prevalence and virulence. The highest prevalence (>80%) and virulence are found in countries with low socioeconomic status and sanitation standards such as regions in Africa and Western Asia.
Gastric adenocarcinoma is the fourth-commonest cause of cancer-related death globally, leading to 660,000 deaths in 2022.
Lagergren and colleagues cited the need for research to delineate high-risk individuals who would benefit rom HP screening and eradication.
This study was supported by the Sjoberg Foundation, Nordic Cancer Union, Stockholm County Council, and Stockholm Cancer Society. The authors had no conflicts of interest to disclose.
Helicobacter pylori (HP) eradication reduced the risk of gastric noncardia adenocarcinoma in five Scandinavian countries, a population-based study in Gastroenterology reported. Risk became virtually similar to the background population from 11 years after treatment onward.
HP infection of the stomach is the main established risk factor for this tumor, but not much was known about the impact of eradication on long-term risk, particularly in Western populations, noted investigators led by Jesper Lagengren, MD, a gastrointestinal surgeon and professor at the Karolinksa Institutet in Stockholm, Sweden. Research with longer follow-up has reported contradictory results.
The study cohort included all adults treated for HP from 1995 to 2019 in Denmark, Finland, Iceland, Norway, and Sweden. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were calculated by comparing the gastric noncardia adenocarcinoma incidence in the study cohort with the incidence in the background population of the same age, sex, calendar period, and country.
The 659,592 treated participants were 54.3% women, 61.5% age 50 or younger, and had no serious comorbidities. They contributed to 5,480,873 person-years at risk with a mean follow-up of 8.3 years. Treatment consisted of a minimum one-week antibiotic regimen with two of amoxicillin, clarithromycin, or metronidazole, in combination with a proton pump inhibitor. This is the recommended regimen in the Nordic countries, where it achieves successful eradication in 90% of infected individuals.
Among these patients, 1311 developed gastric noncardia adenocarcinoma. Over as many as 24 years of follow-up, the SIR in treated HP patients was initially significantly higher than in the background population at 2.27 (95% confidence interval [CI], 2.10-2.44) at 1 to 5 years after treatment. By 6 to 10 years the SIR had dropped to 1.34 (1.21-1.48) and by 11 to 24 years it further fell to 1.11 (.98-1.27). In terms of observed vs expected cases, that translated to 702 vs 310 at 1 to 5 years, 374 vs 270 at 6 to 10 years, and 235 vs 211 from 11 to 24 years.
The results of the Nordic study align with systematic reviews from Asian populations indicating that eradication reduces the risk of gastric cancer, the authors said.
They noted gastric HP infection is the most prevalent bacterial infection worldwide, found in approximately 50% of the global population but with striking geographical variations in prevalence and virulence. The highest prevalence (>80%) and virulence are found in countries with low socioeconomic status and sanitation standards such as regions in Africa and Western Asia.
Gastric adenocarcinoma is the fourth-commonest cause of cancer-related death globally, leading to 660,000 deaths in 2022.
Lagergren and colleagues cited the need for research to delineate high-risk individuals who would benefit rom HP screening and eradication.
This study was supported by the Sjoberg Foundation, Nordic Cancer Union, Stockholm County Council, and Stockholm Cancer Society. The authors had no conflicts of interest to disclose.
Helicobacter pylori (HP) eradication reduced the risk of gastric noncardia adenocarcinoma in five Scandinavian countries, a population-based study in Gastroenterology reported. Risk became virtually similar to the background population from 11 years after treatment onward.
HP infection of the stomach is the main established risk factor for this tumor, but not much was known about the impact of eradication on long-term risk, particularly in Western populations, noted investigators led by Jesper Lagengren, MD, a gastrointestinal surgeon and professor at the Karolinksa Institutet in Stockholm, Sweden. Research with longer follow-up has reported contradictory results.
The study cohort included all adults treated for HP from 1995 to 2019 in Denmark, Finland, Iceland, Norway, and Sweden. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were calculated by comparing the gastric noncardia adenocarcinoma incidence in the study cohort with the incidence in the background population of the same age, sex, calendar period, and country.
The 659,592 treated participants were 54.3% women, 61.5% age 50 or younger, and had no serious comorbidities. They contributed to 5,480,873 person-years at risk with a mean follow-up of 8.3 years. Treatment consisted of a minimum one-week antibiotic regimen with two of amoxicillin, clarithromycin, or metronidazole, in combination with a proton pump inhibitor. This is the recommended regimen in the Nordic countries, where it achieves successful eradication in 90% of infected individuals.
Among these patients, 1311 developed gastric noncardia adenocarcinoma. Over as many as 24 years of follow-up, the SIR in treated HP patients was initially significantly higher than in the background population at 2.27 (95% confidence interval [CI], 2.10-2.44) at 1 to 5 years after treatment. By 6 to 10 years the SIR had dropped to 1.34 (1.21-1.48) and by 11 to 24 years it further fell to 1.11 (.98-1.27). In terms of observed vs expected cases, that translated to 702 vs 310 at 1 to 5 years, 374 vs 270 at 6 to 10 years, and 235 vs 211 from 11 to 24 years.
The results of the Nordic study align with systematic reviews from Asian populations indicating that eradication reduces the risk of gastric cancer, the authors said.
They noted gastric HP infection is the most prevalent bacterial infection worldwide, found in approximately 50% of the global population but with striking geographical variations in prevalence and virulence. The highest prevalence (>80%) and virulence are found in countries with low socioeconomic status and sanitation standards such as regions in Africa and Western Asia.
Gastric adenocarcinoma is the fourth-commonest cause of cancer-related death globally, leading to 660,000 deaths in 2022.
Lagergren and colleagues cited the need for research to delineate high-risk individuals who would benefit rom HP screening and eradication.
This study was supported by the Sjoberg Foundation, Nordic Cancer Union, Stockholm County Council, and Stockholm Cancer Society. The authors had no conflicts of interest to disclose.
FROM GASTROENTEROLOGY
Endoscopic Lifting Agents: AGA Issues New Clinical Practice Update
Published in Clinical Gastroenterology and Hepatology, the commentary reviews available agents and provides clinically relevant commentary on their indications and use — with the caveat that it is not a formal systematic review but rather empirical advice for endoscopists. No formal rating of the quality of evidence or strength of recommendations was performed.
Led by Tobias Zuchelli, MD, a clinical associate professor at Michigan State University and a gastroenterologist at the Henry Ford Health System in Detroit, the expert panel noted that endoscopists are increasingly resecting precancerous lesions and early cancers of the gastrointestinal tract.
“Although new endoscopic procedures have been developed, there had not been much in terms of high-quality guidance on lifting agents,” panelist Amit V. Patel, MD, a professor of medicine at Duke University and director of Endoscopy at Durham Veterans Affairs Medical Center in Durham, North Carolina, told GI & Hepatology News. “With our better understanding and use of techniques, this commentary was timely. It summarizes the available data on the topic and includes our clinical experiences.”
Filling that knowledge gap, the document reviews in detail the timing and methods of agent injection according to procedure type, including the dynamic needle approach, the empirical merits of different agents such as saline (with or without blue contrast) and viscous agents, as well as lift-enhancing assistive devices — for example, the ERBEJET 2 high-pressure water jet, an adjustable hydrosurgical device to facilitate lifting. A chart provides an at-a-glance summary of agents and their pros and cons.
“The feedback from gastroenterologists so far has been quite positive on social media and on GI channels,” Patel said.
Endoscopic resection has evolved from snare polypectomy to endoscopic mucosal resection (EMR) and now, endoscopic submucosal dissection (ESD). The primary benefit of submucosal lifting is the creation of a separating submucosal cushion between the lesion and muscularis propria (MP), which reduces the risk for immediate or delayed perforation of the muscle. Adding a contrast agent also demarcates lesion margins and stains the submucosa, which is fundamental to ESD and allows for assessment of MP injury during EMR.
For decades, homemade solutions were used to lift lesions before removal, with the sentinel agent being normal saline, later mixed with a blue contrast agent, usually indigo carmine or methylene blue. The authors noted that some endoscopists performing ESD start the submucosal injection and incision using a prepackaged viscous solution. “The endoscopist may continue with the viscous fluid or transition to saline or another less expensive solution,” they wrote.
Saline tends to dissipate more quickly than viscous solutions, however. In 2015, the polymer compound SIC-8000 became the first FDA-approved submucosal injection agent. Since then, several other fluids have come on the market, although homemade agents remain available.
Among the update’s recommendations, the fluid selected for EMR should be determined by lesion size, predicted histology, and endoscopist preference. Based on the US Multi-Society Task Force (USMSTF) on Colorectal Cancer, submucosal injection is optional for nonpedunculated colorectal lesions (NPCRLs) of intermediate size (10-19 mm).
Cold snare polypectomy without submucosal injection was later found to be non-inferior to other resection methods utilizing submucosal injection for NPCRLs ≤ 15 mm.
The update noted that the USMSTF considers EMR first-line therapy for most NPCRLs ≥ 20 mm and advocates viscous solutions as preferred, while the use of lifting agents for pedunculated polyps is generally at the discretion of the endoscopist.
For Patel, the main “clinical pearls” in the update are adding a contrast agent to normal saline, using a viscous agent for cold EMR, and manipulating the injection needle first tangentially and then dynamically toward the lumen to maximize separation of the lesion.
In terms of the ideal, an optimal lifting solution would be readily available, inexpensive, and premixed, providing a sustained submucosal cushion. “However, this ideal solution currently does not exist. Injection fluids should, therefore, be selected based on planned resection method, predicted histology, local expertise and preferences, and cost,” the panelists wrote.
Added Patel, “A lot of the agents out there check most of these boxes, but we’re hoping for further development toward the ideal.”
Offering a nonparticipant’s perspective on the overview, Wasseem Skef, MD, a gastroenterologist at UTHealth Houston, found the update very useful. “It always helps to have the literature summarized,” he told GI & Hepatology News. “It’s a pretty balanced review that pulls together the various options but allows people to stick to their preferred practice.”
In his practice, the lifting agent selected depends on the type of resection. “Viscous agents are generally more popular for EMR-type resections,” Skef said. One unanswered question, he noted, is whether adding a hemostatic agent would be superior to a viscous agent alone. “But overall, this is a nice summary of available agents. Gastroenterologists should consider these different options if doing procedures like EMR.”
This review was sponsored by the AGA Institute.
Zuchelli is a consultant for Boston Scientific. Patel consults for Medpace, Renexxion, and Sanofi. Skef reported having no relevant disclosures.
A version of this article appeared on Medscape.com .
Published in Clinical Gastroenterology and Hepatology, the commentary reviews available agents and provides clinically relevant commentary on their indications and use — with the caveat that it is not a formal systematic review but rather empirical advice for endoscopists. No formal rating of the quality of evidence or strength of recommendations was performed.
Led by Tobias Zuchelli, MD, a clinical associate professor at Michigan State University and a gastroenterologist at the Henry Ford Health System in Detroit, the expert panel noted that endoscopists are increasingly resecting precancerous lesions and early cancers of the gastrointestinal tract.
“Although new endoscopic procedures have been developed, there had not been much in terms of high-quality guidance on lifting agents,” panelist Amit V. Patel, MD, a professor of medicine at Duke University and director of Endoscopy at Durham Veterans Affairs Medical Center in Durham, North Carolina, told GI & Hepatology News. “With our better understanding and use of techniques, this commentary was timely. It summarizes the available data on the topic and includes our clinical experiences.”
Filling that knowledge gap, the document reviews in detail the timing and methods of agent injection according to procedure type, including the dynamic needle approach, the empirical merits of different agents such as saline (with or without blue contrast) and viscous agents, as well as lift-enhancing assistive devices — for example, the ERBEJET 2 high-pressure water jet, an adjustable hydrosurgical device to facilitate lifting. A chart provides an at-a-glance summary of agents and their pros and cons.
“The feedback from gastroenterologists so far has been quite positive on social media and on GI channels,” Patel said.
Endoscopic resection has evolved from snare polypectomy to endoscopic mucosal resection (EMR) and now, endoscopic submucosal dissection (ESD). The primary benefit of submucosal lifting is the creation of a separating submucosal cushion between the lesion and muscularis propria (MP), which reduces the risk for immediate or delayed perforation of the muscle. Adding a contrast agent also demarcates lesion margins and stains the submucosa, which is fundamental to ESD and allows for assessment of MP injury during EMR.
For decades, homemade solutions were used to lift lesions before removal, with the sentinel agent being normal saline, later mixed with a blue contrast agent, usually indigo carmine or methylene blue. The authors noted that some endoscopists performing ESD start the submucosal injection and incision using a prepackaged viscous solution. “The endoscopist may continue with the viscous fluid or transition to saline or another less expensive solution,” they wrote.
Saline tends to dissipate more quickly than viscous solutions, however. In 2015, the polymer compound SIC-8000 became the first FDA-approved submucosal injection agent. Since then, several other fluids have come on the market, although homemade agents remain available.
Among the update’s recommendations, the fluid selected for EMR should be determined by lesion size, predicted histology, and endoscopist preference. Based on the US Multi-Society Task Force (USMSTF) on Colorectal Cancer, submucosal injection is optional for nonpedunculated colorectal lesions (NPCRLs) of intermediate size (10-19 mm).
Cold snare polypectomy without submucosal injection was later found to be non-inferior to other resection methods utilizing submucosal injection for NPCRLs ≤ 15 mm.
The update noted that the USMSTF considers EMR first-line therapy for most NPCRLs ≥ 20 mm and advocates viscous solutions as preferred, while the use of lifting agents for pedunculated polyps is generally at the discretion of the endoscopist.
For Patel, the main “clinical pearls” in the update are adding a contrast agent to normal saline, using a viscous agent for cold EMR, and manipulating the injection needle first tangentially and then dynamically toward the lumen to maximize separation of the lesion.
In terms of the ideal, an optimal lifting solution would be readily available, inexpensive, and premixed, providing a sustained submucosal cushion. “However, this ideal solution currently does not exist. Injection fluids should, therefore, be selected based on planned resection method, predicted histology, local expertise and preferences, and cost,” the panelists wrote.
Added Patel, “A lot of the agents out there check most of these boxes, but we’re hoping for further development toward the ideal.”
Offering a nonparticipant’s perspective on the overview, Wasseem Skef, MD, a gastroenterologist at UTHealth Houston, found the update very useful. “It always helps to have the literature summarized,” he told GI & Hepatology News. “It’s a pretty balanced review that pulls together the various options but allows people to stick to their preferred practice.”
In his practice, the lifting agent selected depends on the type of resection. “Viscous agents are generally more popular for EMR-type resections,” Skef said. One unanswered question, he noted, is whether adding a hemostatic agent would be superior to a viscous agent alone. “But overall, this is a nice summary of available agents. Gastroenterologists should consider these different options if doing procedures like EMR.”
This review was sponsored by the AGA Institute.
Zuchelli is a consultant for Boston Scientific. Patel consults for Medpace, Renexxion, and Sanofi. Skef reported having no relevant disclosures.
A version of this article appeared on Medscape.com .
Published in Clinical Gastroenterology and Hepatology, the commentary reviews available agents and provides clinically relevant commentary on their indications and use — with the caveat that it is not a formal systematic review but rather empirical advice for endoscopists. No formal rating of the quality of evidence or strength of recommendations was performed.
Led by Tobias Zuchelli, MD, a clinical associate professor at Michigan State University and a gastroenterologist at the Henry Ford Health System in Detroit, the expert panel noted that endoscopists are increasingly resecting precancerous lesions and early cancers of the gastrointestinal tract.
“Although new endoscopic procedures have been developed, there had not been much in terms of high-quality guidance on lifting agents,” panelist Amit V. Patel, MD, a professor of medicine at Duke University and director of Endoscopy at Durham Veterans Affairs Medical Center in Durham, North Carolina, told GI & Hepatology News. “With our better understanding and use of techniques, this commentary was timely. It summarizes the available data on the topic and includes our clinical experiences.”
Filling that knowledge gap, the document reviews in detail the timing and methods of agent injection according to procedure type, including the dynamic needle approach, the empirical merits of different agents such as saline (with or without blue contrast) and viscous agents, as well as lift-enhancing assistive devices — for example, the ERBEJET 2 high-pressure water jet, an adjustable hydrosurgical device to facilitate lifting. A chart provides an at-a-glance summary of agents and their pros and cons.
“The feedback from gastroenterologists so far has been quite positive on social media and on GI channels,” Patel said.
Endoscopic resection has evolved from snare polypectomy to endoscopic mucosal resection (EMR) and now, endoscopic submucosal dissection (ESD). The primary benefit of submucosal lifting is the creation of a separating submucosal cushion between the lesion and muscularis propria (MP), which reduces the risk for immediate or delayed perforation of the muscle. Adding a contrast agent also demarcates lesion margins and stains the submucosa, which is fundamental to ESD and allows for assessment of MP injury during EMR.
For decades, homemade solutions were used to lift lesions before removal, with the sentinel agent being normal saline, later mixed with a blue contrast agent, usually indigo carmine or methylene blue. The authors noted that some endoscopists performing ESD start the submucosal injection and incision using a prepackaged viscous solution. “The endoscopist may continue with the viscous fluid or transition to saline or another less expensive solution,” they wrote.
Saline tends to dissipate more quickly than viscous solutions, however. In 2015, the polymer compound SIC-8000 became the first FDA-approved submucosal injection agent. Since then, several other fluids have come on the market, although homemade agents remain available.
Among the update’s recommendations, the fluid selected for EMR should be determined by lesion size, predicted histology, and endoscopist preference. Based on the US Multi-Society Task Force (USMSTF) on Colorectal Cancer, submucosal injection is optional for nonpedunculated colorectal lesions (NPCRLs) of intermediate size (10-19 mm).
Cold snare polypectomy without submucosal injection was later found to be non-inferior to other resection methods utilizing submucosal injection for NPCRLs ≤ 15 mm.
The update noted that the USMSTF considers EMR first-line therapy for most NPCRLs ≥ 20 mm and advocates viscous solutions as preferred, while the use of lifting agents for pedunculated polyps is generally at the discretion of the endoscopist.
For Patel, the main “clinical pearls” in the update are adding a contrast agent to normal saline, using a viscous agent for cold EMR, and manipulating the injection needle first tangentially and then dynamically toward the lumen to maximize separation of the lesion.
In terms of the ideal, an optimal lifting solution would be readily available, inexpensive, and premixed, providing a sustained submucosal cushion. “However, this ideal solution currently does not exist. Injection fluids should, therefore, be selected based on planned resection method, predicted histology, local expertise and preferences, and cost,” the panelists wrote.
Added Patel, “A lot of the agents out there check most of these boxes, but we’re hoping for further development toward the ideal.”
Offering a nonparticipant’s perspective on the overview, Wasseem Skef, MD, a gastroenterologist at UTHealth Houston, found the update very useful. “It always helps to have the literature summarized,” he told GI & Hepatology News. “It’s a pretty balanced review that pulls together the various options but allows people to stick to their preferred practice.”
In his practice, the lifting agent selected depends on the type of resection. “Viscous agents are generally more popular for EMR-type resections,” Skef said. One unanswered question, he noted, is whether adding a hemostatic agent would be superior to a viscous agent alone. “But overall, this is a nice summary of available agents. Gastroenterologists should consider these different options if doing procedures like EMR.”
This review was sponsored by the AGA Institute.
Zuchelli is a consultant for Boston Scientific. Patel consults for Medpace, Renexxion, and Sanofi. Skef reported having no relevant disclosures.
A version of this article appeared on Medscape.com .
FROM CLINICAL GASTROENTEROLOGY AND HEPATOLOGY
FDA Issues Early Alert for Medtronic pH-Monitoring Capsules
The notice follows two letters sent in June to customers by the devices’ manufacturer Medtronic and its subsidiary Given Imaging Inc., recommending that customers using certain Bravo CF Capsule Delivery Devices (lot numbers below) for esophageal pH monitoring be removed from all sites of use and sale.
All three of the capsule models listed below are thought to pose a potential risk because the capsules fail to attach to the esophagus’s mucosal wall or to detach from the delivery device as intended owing to a misapplication of adhesive during manufacture. The devices transmit pH data to a recorder attached to the waist of the patient, who interacts with the recorder to indicate symptoms, thereby allowing the physician to compare the symptoms with the occurrence of reflux episodes.
Risks associated with the devices include aspiration/inhalation, perforation of the esophagus, obstruction of the airway, hemorrhage/blood loss/bleeding, laceration of the esophagus, a delay in diagnosis, and foreign bodies remaining in the patient.
Medtronic has reported 33 serious injuries but no deaths associated with the devices.
The lot numbers of the three affected units, which should be identified and quarantined immediately are:
- Bravo CF Capsule Delivery Device, 5-pk, Product Number FGS-0635, Unique Device Identifier-Device Identifier (UDI-DI) 07290101369707
- Bravo CF Capsule Delivery Device 5-pk, FGS-0635, UDI-DI 10613994000009
- Bravo CF Capsule Delivery Device 1-pk, FGS-0636, UDI-DI 07290101369714
These lot identifiers can be found on both the 5-pks’ FGS-0635 outer labels and on the 1-pk FGS-036 individual unit. Customers are advised to return all unused affected products to Medtronic for replacement or credit. In addition, they should pass on this notice to all those who need to be aware within their organizations or to any organizations to which the affected products have been distributed.
They are also advised to check the FDA recall website above for updates as it continues to review information about this potentially high-risk device issue.
Healthcare professionals with concerns or reports of adverse events can contact Medtronic at 800-448-3644 or MedWatch: The FDA Safety Information and Adverse Event Reporting Program.
A version of this article appeared on Medscape.com.
The notice follows two letters sent in June to customers by the devices’ manufacturer Medtronic and its subsidiary Given Imaging Inc., recommending that customers using certain Bravo CF Capsule Delivery Devices (lot numbers below) for esophageal pH monitoring be removed from all sites of use and sale.
All three of the capsule models listed below are thought to pose a potential risk because the capsules fail to attach to the esophagus’s mucosal wall or to detach from the delivery device as intended owing to a misapplication of adhesive during manufacture. The devices transmit pH data to a recorder attached to the waist of the patient, who interacts with the recorder to indicate symptoms, thereby allowing the physician to compare the symptoms with the occurrence of reflux episodes.
Risks associated with the devices include aspiration/inhalation, perforation of the esophagus, obstruction of the airway, hemorrhage/blood loss/bleeding, laceration of the esophagus, a delay in diagnosis, and foreign bodies remaining in the patient.
Medtronic has reported 33 serious injuries but no deaths associated with the devices.
The lot numbers of the three affected units, which should be identified and quarantined immediately are:
- Bravo CF Capsule Delivery Device, 5-pk, Product Number FGS-0635, Unique Device Identifier-Device Identifier (UDI-DI) 07290101369707
- Bravo CF Capsule Delivery Device 5-pk, FGS-0635, UDI-DI 10613994000009
- Bravo CF Capsule Delivery Device 1-pk, FGS-0636, UDI-DI 07290101369714
These lot identifiers can be found on both the 5-pks’ FGS-0635 outer labels and on the 1-pk FGS-036 individual unit. Customers are advised to return all unused affected products to Medtronic for replacement or credit. In addition, they should pass on this notice to all those who need to be aware within their organizations or to any organizations to which the affected products have been distributed.
They are also advised to check the FDA recall website above for updates as it continues to review information about this potentially high-risk device issue.
Healthcare professionals with concerns or reports of adverse events can contact Medtronic at 800-448-3644 or MedWatch: The FDA Safety Information and Adverse Event Reporting Program.
A version of this article appeared on Medscape.com.
The notice follows two letters sent in June to customers by the devices’ manufacturer Medtronic and its subsidiary Given Imaging Inc., recommending that customers using certain Bravo CF Capsule Delivery Devices (lot numbers below) for esophageal pH monitoring be removed from all sites of use and sale.
All three of the capsule models listed below are thought to pose a potential risk because the capsules fail to attach to the esophagus’s mucosal wall or to detach from the delivery device as intended owing to a misapplication of adhesive during manufacture. The devices transmit pH data to a recorder attached to the waist of the patient, who interacts with the recorder to indicate symptoms, thereby allowing the physician to compare the symptoms with the occurrence of reflux episodes.
Risks associated with the devices include aspiration/inhalation, perforation of the esophagus, obstruction of the airway, hemorrhage/blood loss/bleeding, laceration of the esophagus, a delay in diagnosis, and foreign bodies remaining in the patient.
Medtronic has reported 33 serious injuries but no deaths associated with the devices.
The lot numbers of the three affected units, which should be identified and quarantined immediately are:
- Bravo CF Capsule Delivery Device, 5-pk, Product Number FGS-0635, Unique Device Identifier-Device Identifier (UDI-DI) 07290101369707
- Bravo CF Capsule Delivery Device 5-pk, FGS-0635, UDI-DI 10613994000009
- Bravo CF Capsule Delivery Device 1-pk, FGS-0636, UDI-DI 07290101369714
These lot identifiers can be found on both the 5-pks’ FGS-0635 outer labels and on the 1-pk FGS-036 individual unit. Customers are advised to return all unused affected products to Medtronic for replacement or credit. In addition, they should pass on this notice to all those who need to be aware within their organizations or to any organizations to which the affected products have been distributed.
They are also advised to check the FDA recall website above for updates as it continues to review information about this potentially high-risk device issue.
Healthcare professionals with concerns or reports of adverse events can contact Medtronic at 800-448-3644 or MedWatch: The FDA Safety Information and Adverse Event Reporting Program.
A version of this article appeared on Medscape.com.
Celiac Blood Test Eliminates Need for Eating Gluten
Think your patient may have celiac disease? The harsh reality is that current diagnostic tests require patients to consume gluten for an accurate diagnosis, which poses challenges for individuals already avoiding gluten.
A more tolerable approach appears to be on the horizon.
“This is a simple and accurate test that can provide a diagnosis within a very short time frame, without the need for patients to continue eating gluten and feeling sick, or to wait months for a gastroscopy,” Olivia Moscatelli, PhD candidate, Tye-Din Lab, Walter and Eliza Hall Institute and University of Melbourne, Parkville, Australia, told GI & Hepatology News.
The study was published in Gastroenterology.
Most Cases Go Undiagnosed
Celiac disease is an autoimmune disorder triggered by gluten found in wheat, rye, and barley. The only available treatment is a strict, life-long gluten-free diet.
The global prevalence of celiac disease is estimated at around 1%-2%, with 50%-80% of cases either undiagnosed or diagnosed late. That’s because the current reliable diagnosis of celiac disease requires the intake of gluten, which may deter people from seeking a diagnosis.
In earlier work, the researchers, working with Robert Anderson, MBChB, BMedSc, PhD, AGAF, now with Novoviah Pharmaceuticals, made the unexpected discovery that interleukin-2 (IL-2) spiked in the blood of people with celiac disease shortly after they ate gluten.
But would this signal be present when no gluten had been consumed?
The team developed and tested a simple whole blood assay measuring IL-2 release (WBAIL- 2) for detecting gluten-specific T cells to aid in diagnosing celiac disease.
They collected blood samples from 181 volunteers — 75 with treated celiac disease on a gluten-free diet, 13 with active untreated celiac disease, 32 with nonceliac gluten sensitivity and 61 healthy controls. The blood samples were mixed with gluten in a test tube for a day to see if the IL-2 signal appeared.
The WBAIL-2 assay demonstrated high accuracy for celiac disease, even in patients following a strict gluten-free diet.
For patients with HLA-DQ2.5+ genetics, sensitivity was 90% and specificity was 95%, with lower sensitivity (56%) for patients with HLA-DQ8+ celiac disease.
The WBAIL-2 assay correlated strongly with the frequency of tetramer-positive gluten-specific CD4+ T cells used to diagnose celiac disease and monitor treatment effectiveness, and with serum IL-2 levels after gluten challenge.
The strength of the IL-2 signal correlated with the severity of a patient’s symptoms, “allowing us to predict how severely a person with celiac disease might react to gluten, without them actually having to eat it,” Moscatelli said in a news release.
“Current diagnostic practice involves a blood-based serology test followed by a confirmatory gastroscopy if positive. Both tests require the patient to eat gluten daily for 6-12 weeks prior for accurate results. We envision the new blood test (IL-2 whole blood assay) will replace the invasive gastroscopy as the confirmatory test following positive serology,” Moscatelli told GI & Hepatology News.
“In people already following a gluten-free diet, we propose they would have this new blood test done on two separate occasions and two positive results would be required for a celiac diagnosis. This would allow a large number of people who previously have been unable to go through the current diagnostic process to receive a diagnosis,” Moscatelli said.
Practice Changing Potential
A blood-based test that can accurately detect celiac disease without the need for a gluten challenge would be “welcome and practice changing,” said Christopher Cao, MD, director, Celiac Disease Program, Division of Gastroenterology, Mount Sinai Health System, New York City.
“A typical ‘gluten challenge’ involves eating the equivalent of 1-2 slices of bread daily for the course of 6 weeks, and this may be incredibly difficult for patients who have already been on a gluten-free diet prior to an official celiac disease diagnosis. Inability to perform a gluten challenge limits the ability to make an accurate celiac disease diagnosis,” Cao told GI & Hepatology News.
“This study shows that gluten-stimulated interleukin release 2 assays may correlate with the presence of pathogenic gluten-specific CD4+ T cell response in celiac disease,” Cao noted.
He cautioned that “further large cohort, multicenter prospective studies are needed to assess generalizability and may be helpful in evaluating the accuracy of WBAIL-2 in non-HLA DQ2.5 genotypes.”
Other considerations prior to implementation may include reproducibility across different laboratories and overall cost effectiveness, Cao said. “Ultimately in clinic, the role of WBAIL-2 will need to be better defined within the algorithm of celiac disease testing,” he added.
The Path Ahead
The researchers plan to test the performance of the IL-2 whole blood assay in a pediatric cohort, as well as in other countries to demonstrate the reproducibility of the test. In these studies, the test will likely be performed alongside the current diagnostic tests (serology and gastroscopy), Moscatelli told GI & Hepatology News.
“There are some validation studies starting in other countries already as many celiac clinicians globally are interested in bringing this test to their clinical practice. I believe the plan is to have this as an approved diagnostic test for celiac disease worldwide,” she said.
Novoviah Pharmaceuticals is managing the commercialization of the test, and the plan is to get it into clinical practice in the next 2 years, Moscatelli said.
The research was supported by Coeliac Australia, Novoviah Pharmaceuticals (who provided the proprietary test for this study), Beck Family Foundation, Butterfield Family, the Veith Foundation. A complete list of author disclosures is available with the original article. Cao had no relevant disclosures.
A version of this article appeared on Medscape.com.
Think your patient may have celiac disease? The harsh reality is that current diagnostic tests require patients to consume gluten for an accurate diagnosis, which poses challenges for individuals already avoiding gluten.
A more tolerable approach appears to be on the horizon.
“This is a simple and accurate test that can provide a diagnosis within a very short time frame, without the need for patients to continue eating gluten and feeling sick, or to wait months for a gastroscopy,” Olivia Moscatelli, PhD candidate, Tye-Din Lab, Walter and Eliza Hall Institute and University of Melbourne, Parkville, Australia, told GI & Hepatology News.
The study was published in Gastroenterology.
Most Cases Go Undiagnosed
Celiac disease is an autoimmune disorder triggered by gluten found in wheat, rye, and barley. The only available treatment is a strict, life-long gluten-free diet.
The global prevalence of celiac disease is estimated at around 1%-2%, with 50%-80% of cases either undiagnosed or diagnosed late. That’s because the current reliable diagnosis of celiac disease requires the intake of gluten, which may deter people from seeking a diagnosis.
In earlier work, the researchers, working with Robert Anderson, MBChB, BMedSc, PhD, AGAF, now with Novoviah Pharmaceuticals, made the unexpected discovery that interleukin-2 (IL-2) spiked in the blood of people with celiac disease shortly after they ate gluten.
But would this signal be present when no gluten had been consumed?
The team developed and tested a simple whole blood assay measuring IL-2 release (WBAIL- 2) for detecting gluten-specific T cells to aid in diagnosing celiac disease.
They collected blood samples from 181 volunteers — 75 with treated celiac disease on a gluten-free diet, 13 with active untreated celiac disease, 32 with nonceliac gluten sensitivity and 61 healthy controls. The blood samples were mixed with gluten in a test tube for a day to see if the IL-2 signal appeared.
The WBAIL-2 assay demonstrated high accuracy for celiac disease, even in patients following a strict gluten-free diet.
For patients with HLA-DQ2.5+ genetics, sensitivity was 90% and specificity was 95%, with lower sensitivity (56%) for patients with HLA-DQ8+ celiac disease.
The WBAIL-2 assay correlated strongly with the frequency of tetramer-positive gluten-specific CD4+ T cells used to diagnose celiac disease and monitor treatment effectiveness, and with serum IL-2 levels after gluten challenge.
The strength of the IL-2 signal correlated with the severity of a patient’s symptoms, “allowing us to predict how severely a person with celiac disease might react to gluten, without them actually having to eat it,” Moscatelli said in a news release.
“Current diagnostic practice involves a blood-based serology test followed by a confirmatory gastroscopy if positive. Both tests require the patient to eat gluten daily for 6-12 weeks prior for accurate results. We envision the new blood test (IL-2 whole blood assay) will replace the invasive gastroscopy as the confirmatory test following positive serology,” Moscatelli told GI & Hepatology News.
“In people already following a gluten-free diet, we propose they would have this new blood test done on two separate occasions and two positive results would be required for a celiac diagnosis. This would allow a large number of people who previously have been unable to go through the current diagnostic process to receive a diagnosis,” Moscatelli said.
Practice Changing Potential
A blood-based test that can accurately detect celiac disease without the need for a gluten challenge would be “welcome and practice changing,” said Christopher Cao, MD, director, Celiac Disease Program, Division of Gastroenterology, Mount Sinai Health System, New York City.
“A typical ‘gluten challenge’ involves eating the equivalent of 1-2 slices of bread daily for the course of 6 weeks, and this may be incredibly difficult for patients who have already been on a gluten-free diet prior to an official celiac disease diagnosis. Inability to perform a gluten challenge limits the ability to make an accurate celiac disease diagnosis,” Cao told GI & Hepatology News.
“This study shows that gluten-stimulated interleukin release 2 assays may correlate with the presence of pathogenic gluten-specific CD4+ T cell response in celiac disease,” Cao noted.
He cautioned that “further large cohort, multicenter prospective studies are needed to assess generalizability and may be helpful in evaluating the accuracy of WBAIL-2 in non-HLA DQ2.5 genotypes.”
Other considerations prior to implementation may include reproducibility across different laboratories and overall cost effectiveness, Cao said. “Ultimately in clinic, the role of WBAIL-2 will need to be better defined within the algorithm of celiac disease testing,” he added.
The Path Ahead
The researchers plan to test the performance of the IL-2 whole blood assay in a pediatric cohort, as well as in other countries to demonstrate the reproducibility of the test. In these studies, the test will likely be performed alongside the current diagnostic tests (serology and gastroscopy), Moscatelli told GI & Hepatology News.
“There are some validation studies starting in other countries already as many celiac clinicians globally are interested in bringing this test to their clinical practice. I believe the plan is to have this as an approved diagnostic test for celiac disease worldwide,” she said.
Novoviah Pharmaceuticals is managing the commercialization of the test, and the plan is to get it into clinical practice in the next 2 years, Moscatelli said.
The research was supported by Coeliac Australia, Novoviah Pharmaceuticals (who provided the proprietary test for this study), Beck Family Foundation, Butterfield Family, the Veith Foundation. A complete list of author disclosures is available with the original article. Cao had no relevant disclosures.
A version of this article appeared on Medscape.com.
Think your patient may have celiac disease? The harsh reality is that current diagnostic tests require patients to consume gluten for an accurate diagnosis, which poses challenges for individuals already avoiding gluten.
A more tolerable approach appears to be on the horizon.
“This is a simple and accurate test that can provide a diagnosis within a very short time frame, without the need for patients to continue eating gluten and feeling sick, or to wait months for a gastroscopy,” Olivia Moscatelli, PhD candidate, Tye-Din Lab, Walter and Eliza Hall Institute and University of Melbourne, Parkville, Australia, told GI & Hepatology News.
The study was published in Gastroenterology.
Most Cases Go Undiagnosed
Celiac disease is an autoimmune disorder triggered by gluten found in wheat, rye, and barley. The only available treatment is a strict, life-long gluten-free diet.
The global prevalence of celiac disease is estimated at around 1%-2%, with 50%-80% of cases either undiagnosed or diagnosed late. That’s because the current reliable diagnosis of celiac disease requires the intake of gluten, which may deter people from seeking a diagnosis.
In earlier work, the researchers, working with Robert Anderson, MBChB, BMedSc, PhD, AGAF, now with Novoviah Pharmaceuticals, made the unexpected discovery that interleukin-2 (IL-2) spiked in the blood of people with celiac disease shortly after they ate gluten.
But would this signal be present when no gluten had been consumed?
The team developed and tested a simple whole blood assay measuring IL-2 release (WBAIL- 2) for detecting gluten-specific T cells to aid in diagnosing celiac disease.
They collected blood samples from 181 volunteers — 75 with treated celiac disease on a gluten-free diet, 13 with active untreated celiac disease, 32 with nonceliac gluten sensitivity and 61 healthy controls. The blood samples were mixed with gluten in a test tube for a day to see if the IL-2 signal appeared.
The WBAIL-2 assay demonstrated high accuracy for celiac disease, even in patients following a strict gluten-free diet.
For patients with HLA-DQ2.5+ genetics, sensitivity was 90% and specificity was 95%, with lower sensitivity (56%) for patients with HLA-DQ8+ celiac disease.
The WBAIL-2 assay correlated strongly with the frequency of tetramer-positive gluten-specific CD4+ T cells used to diagnose celiac disease and monitor treatment effectiveness, and with serum IL-2 levels after gluten challenge.
The strength of the IL-2 signal correlated with the severity of a patient’s symptoms, “allowing us to predict how severely a person with celiac disease might react to gluten, without them actually having to eat it,” Moscatelli said in a news release.
“Current diagnostic practice involves a blood-based serology test followed by a confirmatory gastroscopy if positive. Both tests require the patient to eat gluten daily for 6-12 weeks prior for accurate results. We envision the new blood test (IL-2 whole blood assay) will replace the invasive gastroscopy as the confirmatory test following positive serology,” Moscatelli told GI & Hepatology News.
“In people already following a gluten-free diet, we propose they would have this new blood test done on two separate occasions and two positive results would be required for a celiac diagnosis. This would allow a large number of people who previously have been unable to go through the current diagnostic process to receive a diagnosis,” Moscatelli said.
Practice Changing Potential
A blood-based test that can accurately detect celiac disease without the need for a gluten challenge would be “welcome and practice changing,” said Christopher Cao, MD, director, Celiac Disease Program, Division of Gastroenterology, Mount Sinai Health System, New York City.
“A typical ‘gluten challenge’ involves eating the equivalent of 1-2 slices of bread daily for the course of 6 weeks, and this may be incredibly difficult for patients who have already been on a gluten-free diet prior to an official celiac disease diagnosis. Inability to perform a gluten challenge limits the ability to make an accurate celiac disease diagnosis,” Cao told GI & Hepatology News.
“This study shows that gluten-stimulated interleukin release 2 assays may correlate with the presence of pathogenic gluten-specific CD4+ T cell response in celiac disease,” Cao noted.
He cautioned that “further large cohort, multicenter prospective studies are needed to assess generalizability and may be helpful in evaluating the accuracy of WBAIL-2 in non-HLA DQ2.5 genotypes.”
Other considerations prior to implementation may include reproducibility across different laboratories and overall cost effectiveness, Cao said. “Ultimately in clinic, the role of WBAIL-2 will need to be better defined within the algorithm of celiac disease testing,” he added.
The Path Ahead
The researchers plan to test the performance of the IL-2 whole blood assay in a pediatric cohort, as well as in other countries to demonstrate the reproducibility of the test. In these studies, the test will likely be performed alongside the current diagnostic tests (serology and gastroscopy), Moscatelli told GI & Hepatology News.
“There are some validation studies starting in other countries already as many celiac clinicians globally are interested in bringing this test to their clinical practice. I believe the plan is to have this as an approved diagnostic test for celiac disease worldwide,” she said.
Novoviah Pharmaceuticals is managing the commercialization of the test, and the plan is to get it into clinical practice in the next 2 years, Moscatelli said.
The research was supported by Coeliac Australia, Novoviah Pharmaceuticals (who provided the proprietary test for this study), Beck Family Foundation, Butterfield Family, the Veith Foundation. A complete list of author disclosures is available with the original article. Cao had no relevant disclosures.
A version of this article appeared on Medscape.com.
FROM GASTROENTEROLOGY
Journal Highlights: January-April 2025
Esophagus/Motility
Carlson DA, et al. A Standardized Approach to Performing and Interpreting Functional Lumen Imaging Probe Panometry for Esophageal Motility Disorders: The Dallas Consensus. Gastroenterology. 2025 Feb. doi: 10.1053/j.gastro.2025.01.234.
Parkman HP, et al; NIDDK Gastroparesis Clinical Research Consortium. Characterization of Patients with Symptoms of Gastroparesis Having Frequent Emergency Department Visits and Hospitalizations. Clin Gastroenterol Hepatol. 2025 Apr. doi: 10.1016/j.cgh.2025.01.033.
Dellon ES, et al. Long-term Safety and Efficacy of Budesonide Oral Suspension for Eosinophilic Esophagitis: A 4-Year, Phase 3, Open-Label Study. Clin Gastroenterol Hepatol. 2025 Feb. doi: 10.1016/j.cgh.2024.12.024.
Small Bowel
Hård Af Segerstad EM, et al; TEDDY Study Group. Early Dietary Fiber Intake Reduces Celiac Disease Risk in Genetically Prone Children: Insights From the TEDDY Study. Gastroenterology. 2025 Feb. doi: 10.1053/j.gastro.2025.01.241.
Colon
Shaukat A, et al. AGA Clinical Practice Update on Current Role of Blood Tests for Colorectal Cancer Screening: Commentary. Clin Gastroenterol Hepatol. 2025 Apr. doi: 10.1016/j.cgh.2025.04.003.
Bergman D, et al. Cholecystectomy is a Risk Factor for Microscopic Colitis: A Nationwide Population-based Matched Case Control Study. Clin Gastroenterol Hepatol. 2025 Mar. doi: 10.1016/j.cgh.2024.12.032.
Inflammatory Bowel Disease
Ben-Horin S, et al; Israeli IBD Research Nucleus (IIRN). Capsule Endoscopy-Guided Proactive Treat-to-Target Versus Continued Standard Care in Patients With Quiescent Crohn’s Disease: A Randomized Controlled Trial. Gastroenterology. 2025 Mar. doi: 10.1053/j.gastro.2025.02.031.
Pancreas
Guilabert L, et al; ERICA Consortium. Impact of Fluid Therapy in the Emergency Department in Acute Pancreatitis: a posthoc analysis of the WATERFALL Trial. Clin Gastroenterol Hepatol. 2025 Apr. doi: 10.1016/j.cgh.2025.01.038.
Hepatology
Rhee H, et al. Noncontrast Magnetic Resonance Imaging vs Ultrasonography for Hepatocellular Carcinoma Surveillance: A Randomized, Single-Center Trial. Gastroenterology. 2025 Jan. doi: 10.1053/j.gastro.2024.12.035.
Kronsten VT, et al. Hepatic Encephalopathy: When Lactulose and Rifaximin Are Not Working. Gastroenterology. 2025 Jan. doi: 10.1053/j.gastro.2025.01.010.
Edelson JC, et al. Accuracy and Safety of Endoscopic Ultrasound–Guided Liver Biopsy in Patients with Metabolic Dysfunction–Associated Liver Disease. Tech Innov Gastrointest Endosc. 2025 Apr. doi: 10.1016/j.tige.2025.250918.
Miscellaneous
Martin J, et al. Practical and Impactful Tips for Private Industry Collaborations with Gastroenterology Practices. Clin Gastroenterol Hepatol. 2025 Mar. doi: 10.1016/j.cgh.2025.01.021.
Tejada, Natalia et al. Glucagon-like Peptide-1 Receptor Agonists Are Not Associated With Increased Incidence of Pneumonia After Endoscopic Procedures. Tech Innov Gastrointest Endosc. 2025 Apr. doi: 10.1016/j.tige.2025.250925.
Lazaridis KN, et al. Microplastics and Nanoplastics and the Digestive System. Gastro Hep Adv. 2025 May. doi: 10.1016/j.gastha.2025.100694.
Dr. Trieu is assistant professor of medicine, interventional endoscopy, in the Division of Gastroenterology at Washington University in St. Louis School of Medicine, Missouri.
Esophagus/Motility
Carlson DA, et al. A Standardized Approach to Performing and Interpreting Functional Lumen Imaging Probe Panometry for Esophageal Motility Disorders: The Dallas Consensus. Gastroenterology. 2025 Feb. doi: 10.1053/j.gastro.2025.01.234.
Parkman HP, et al; NIDDK Gastroparesis Clinical Research Consortium. Characterization of Patients with Symptoms of Gastroparesis Having Frequent Emergency Department Visits and Hospitalizations. Clin Gastroenterol Hepatol. 2025 Apr. doi: 10.1016/j.cgh.2025.01.033.
Dellon ES, et al. Long-term Safety and Efficacy of Budesonide Oral Suspension for Eosinophilic Esophagitis: A 4-Year, Phase 3, Open-Label Study. Clin Gastroenterol Hepatol. 2025 Feb. doi: 10.1016/j.cgh.2024.12.024.
Small Bowel
Hård Af Segerstad EM, et al; TEDDY Study Group. Early Dietary Fiber Intake Reduces Celiac Disease Risk in Genetically Prone Children: Insights From the TEDDY Study. Gastroenterology. 2025 Feb. doi: 10.1053/j.gastro.2025.01.241.
Colon
Shaukat A, et al. AGA Clinical Practice Update on Current Role of Blood Tests for Colorectal Cancer Screening: Commentary. Clin Gastroenterol Hepatol. 2025 Apr. doi: 10.1016/j.cgh.2025.04.003.
Bergman D, et al. Cholecystectomy is a Risk Factor for Microscopic Colitis: A Nationwide Population-based Matched Case Control Study. Clin Gastroenterol Hepatol. 2025 Mar. doi: 10.1016/j.cgh.2024.12.032.
Inflammatory Bowel Disease
Ben-Horin S, et al; Israeli IBD Research Nucleus (IIRN). Capsule Endoscopy-Guided Proactive Treat-to-Target Versus Continued Standard Care in Patients With Quiescent Crohn’s Disease: A Randomized Controlled Trial. Gastroenterology. 2025 Mar. doi: 10.1053/j.gastro.2025.02.031.
Pancreas
Guilabert L, et al; ERICA Consortium. Impact of Fluid Therapy in the Emergency Department in Acute Pancreatitis: a posthoc analysis of the WATERFALL Trial. Clin Gastroenterol Hepatol. 2025 Apr. doi: 10.1016/j.cgh.2025.01.038.
Hepatology
Rhee H, et al. Noncontrast Magnetic Resonance Imaging vs Ultrasonography for Hepatocellular Carcinoma Surveillance: A Randomized, Single-Center Trial. Gastroenterology. 2025 Jan. doi: 10.1053/j.gastro.2024.12.035.
Kronsten VT, et al. Hepatic Encephalopathy: When Lactulose and Rifaximin Are Not Working. Gastroenterology. 2025 Jan. doi: 10.1053/j.gastro.2025.01.010.
Edelson JC, et al. Accuracy and Safety of Endoscopic Ultrasound–Guided Liver Biopsy in Patients with Metabolic Dysfunction–Associated Liver Disease. Tech Innov Gastrointest Endosc. 2025 Apr. doi: 10.1016/j.tige.2025.250918.
Miscellaneous
Martin J, et al. Practical and Impactful Tips for Private Industry Collaborations with Gastroenterology Practices. Clin Gastroenterol Hepatol. 2025 Mar. doi: 10.1016/j.cgh.2025.01.021.
Tejada, Natalia et al. Glucagon-like Peptide-1 Receptor Agonists Are Not Associated With Increased Incidence of Pneumonia After Endoscopic Procedures. Tech Innov Gastrointest Endosc. 2025 Apr. doi: 10.1016/j.tige.2025.250925.
Lazaridis KN, et al. Microplastics and Nanoplastics and the Digestive System. Gastro Hep Adv. 2025 May. doi: 10.1016/j.gastha.2025.100694.
Dr. Trieu is assistant professor of medicine, interventional endoscopy, in the Division of Gastroenterology at Washington University in St. Louis School of Medicine, Missouri.
Esophagus/Motility
Carlson DA, et al. A Standardized Approach to Performing and Interpreting Functional Lumen Imaging Probe Panometry for Esophageal Motility Disorders: The Dallas Consensus. Gastroenterology. 2025 Feb. doi: 10.1053/j.gastro.2025.01.234.
Parkman HP, et al; NIDDK Gastroparesis Clinical Research Consortium. Characterization of Patients with Symptoms of Gastroparesis Having Frequent Emergency Department Visits and Hospitalizations. Clin Gastroenterol Hepatol. 2025 Apr. doi: 10.1016/j.cgh.2025.01.033.
Dellon ES, et al. Long-term Safety and Efficacy of Budesonide Oral Suspension for Eosinophilic Esophagitis: A 4-Year, Phase 3, Open-Label Study. Clin Gastroenterol Hepatol. 2025 Feb. doi: 10.1016/j.cgh.2024.12.024.
Small Bowel
Hård Af Segerstad EM, et al; TEDDY Study Group. Early Dietary Fiber Intake Reduces Celiac Disease Risk in Genetically Prone Children: Insights From the TEDDY Study. Gastroenterology. 2025 Feb. doi: 10.1053/j.gastro.2025.01.241.
Colon
Shaukat A, et al. AGA Clinical Practice Update on Current Role of Blood Tests for Colorectal Cancer Screening: Commentary. Clin Gastroenterol Hepatol. 2025 Apr. doi: 10.1016/j.cgh.2025.04.003.
Bergman D, et al. Cholecystectomy is a Risk Factor for Microscopic Colitis: A Nationwide Population-based Matched Case Control Study. Clin Gastroenterol Hepatol. 2025 Mar. doi: 10.1016/j.cgh.2024.12.032.
Inflammatory Bowel Disease
Ben-Horin S, et al; Israeli IBD Research Nucleus (IIRN). Capsule Endoscopy-Guided Proactive Treat-to-Target Versus Continued Standard Care in Patients With Quiescent Crohn’s Disease: A Randomized Controlled Trial. Gastroenterology. 2025 Mar. doi: 10.1053/j.gastro.2025.02.031.
Pancreas
Guilabert L, et al; ERICA Consortium. Impact of Fluid Therapy in the Emergency Department in Acute Pancreatitis: a posthoc analysis of the WATERFALL Trial. Clin Gastroenterol Hepatol. 2025 Apr. doi: 10.1016/j.cgh.2025.01.038.
Hepatology
Rhee H, et al. Noncontrast Magnetic Resonance Imaging vs Ultrasonography for Hepatocellular Carcinoma Surveillance: A Randomized, Single-Center Trial. Gastroenterology. 2025 Jan. doi: 10.1053/j.gastro.2024.12.035.
Kronsten VT, et al. Hepatic Encephalopathy: When Lactulose and Rifaximin Are Not Working. Gastroenterology. 2025 Jan. doi: 10.1053/j.gastro.2025.01.010.
Edelson JC, et al. Accuracy and Safety of Endoscopic Ultrasound–Guided Liver Biopsy in Patients with Metabolic Dysfunction–Associated Liver Disease. Tech Innov Gastrointest Endosc. 2025 Apr. doi: 10.1016/j.tige.2025.250918.
Miscellaneous
Martin J, et al. Practical and Impactful Tips for Private Industry Collaborations with Gastroenterology Practices. Clin Gastroenterol Hepatol. 2025 Mar. doi: 10.1016/j.cgh.2025.01.021.
Tejada, Natalia et al. Glucagon-like Peptide-1 Receptor Agonists Are Not Associated With Increased Incidence of Pneumonia After Endoscopic Procedures. Tech Innov Gastrointest Endosc. 2025 Apr. doi: 10.1016/j.tige.2025.250925.
Lazaridis KN, et al. Microplastics and Nanoplastics and the Digestive System. Gastro Hep Adv. 2025 May. doi: 10.1016/j.gastha.2025.100694.
Dr. Trieu is assistant professor of medicine, interventional endoscopy, in the Division of Gastroenterology at Washington University in St. Louis School of Medicine, Missouri.