Microorganisms in the human digestive tract are linked to 29 specific health conditions, including chronic obstructive pulmonary disease, high blood pressure, and type 2 diabetes, according to a genome analysis in more than 400,000 individuals.
Although previous studies have suggested a link between gut microbiota and diseases in humans, “the extent to which the human gut microbiome can be considered a determinant of disease and healthy aging remains unknown,” Hilde E. Groot, MD, of the University of Groningen (The Netherlands), said in a presentation at the virtual annual congress of the European Society of Cardiology.
To identify the spectrum of diseases linked to the gut microbiome, the researchers identified 422,417 unrelated adults of White British ancestry with genotype and matching genetic data. The average age of the participants was 57 years and 46% were male.
The researchers conducted a phenomewide association study including 35 distinct single-nucleotide polymorphisms (SNPs) that are known to influence the microbiome of the human gut.
Overall, seven SNPs were significantly associated with 29 disease outcomes including hypertension, type 2 diabetes, hypercholesterolemia, heart failure, renal failure, and osteoarthritis.
In addition, after a further sensitivity analysis using a Mendelian randomization (MR) approach, associations between Ruminococcus flavefaciens and hypertension and between Clostridium and platelet count might point to a causal link, the researchers said.
“Over the past few years, the amount of research concerning the human gut microbiome and the associations with health and disease has tremendously increased. However, most studies investigated one or a few traits. The strength of our study is the possibility to cover a wide range of traits simultaneously within one population,” Dr. Groot said in an interview.
“Our data support the hypothesis that the human gut microbiome is a complex system, involved in many pathophysiological mechanisms in the human body. So, our results are additional to earlier research and strengthen this hypothesis,” Dr. Groot added.
“Microbiota and their metabolites might be of importance in the interplay between overlapping pathophysiological processes, and could serve as potential therapeutic targets for the maintenance of health and prevention and treatment of cardiovascular diseases. However, before it is possible to give advice for the public and medical practice, further research is needed to study causality,” she emphasized.
“Currently, it is too soon to advise patients concerning their microbiome,” Dr. Groot noted. “However, genetic studies like ours might help other researchers to study causality between the gut microbiome and particular traits, which might potentially lead to new therapeutic targets. Next to genetic variants as a proxy, we’re currently studying the gut microbiome composition in myocardial infarction patients and healthy controls in a longitudinal setting.”
“Previous studies have suggested a potential link between the gut microbiome and the development of cardiovascular disease, type 2 diabetes mellitus, and other chronic disorders,” Carol Ann Remme, MD, of the Amsterdam University Medical Center, said in an interview. “However, it is challenging to study the effect of gut microbiome composition in large patient cohorts. As an alternative approach, the study authors showed in a very large population that genetic variants previously shown to influence gut microbiome composition were significantly associated with conditions such as hypertension, type 2 diabetes, hypercholesterolemia, and heart failure.”
The study is unique in that it employed a very large cohort of more than 400,000 individuals, which is typically required to be able to draw clear conclusions, Dr. Remme continued. “The authors were able to further refine their findings by linking genetic variants known to influence specific gut bacteria to some particular disorders,” she noted.
“It is becoming increasingly clear that an individual’s gut microbiome composition, which is defined by both genetic and environmental factors such as diet, may affect his/her susceptibility to certain diseases – including cardiovascular – in addition to disease progression and outcome,” said Dr. Remme. “This may ultimately lead to development of novel, personalized strategies for risk stratification in addition to potential preventive measures targeting the gut microbiome. I expect this area of research will become increasingly important in the coming years.”
The study received no outside funding. Dr. Groot and colleagues had no financial conflicts to disclose. Dr. Remme had no financial conflicts to disclose.