Gut microbes associated with diet, metabolic health

A diet rich in healthy and plant-based foods is linked with the presence and abundance of certain gut microbes that are also associated with a lower risk of developing conditions such as obesity, type 2 diabetes and cardiovascular disease, according to a new study from Massachusetts General Hospital in Boston published in the journal Nature Medicine.

The PREDICT 1 (Personalized Responses to Dietary Composition Trial 1) metagenomic study analyzed detailed data on the composition of participants' microbiomes, their dietary habits, and cardiometabolic blood biomarkers. The researchers said they found strong evidence that the microbiome is linked with specific foods and diets, and that, in turn, its composition is also associated with levels of metabolic biomarkers of disease. Further, the microbiome has a greater association with these markers than other factors, such as genetics.

PREDICT 1 is an international collaboration to study links between diet, the microbiome, and biomarkers of cardiometabolic health. The researchers gathered microbiome sequence data, detailed long-term dietary information, and results of hundreds of cardiometabolic blood markers from just over 1,100 participants in the United Kingdom and United States.

The researchers found that participants who ate a diet rich in healthy, plant-based foods were more likely to have high levels of specific gut microbes. The makeup of participants' gut microbiomes was strongly associated with specific nutrients, foods, food groups and general dietary indices or overall diet composition. The researchers also found robust microbiome-based biomarkers of obesity as well as markers for cardiovascular disease and impaired glucose tolerance.

For example, having a microbiome rich in Prevotella copri and Blastocystis species was associated with maintaining a favorable blood sugar level after a meal. Other species were linked to lower post-meal levels of blood fats and markers of inflammation. The trends they found were so consistent, the researchers believe that their microbiome data can be used to determine the risk of cardiometabolic disease among people who do not yet have symptoms, and possibly to prescribe a personalized diet designed specifically to improve someone's health.

"This study demonstrates a clear association between specific microbial species in the gut, certain foods, and risk of some common diseases," said Andrew Chan, MD, MPH, the study's senior author, a gastroenterologist, chief of the Clinical and Translational Epidemiology Unit at Massachusetts General Hospital in Boston, and professor of medicine at Harvard Medical School, in a statement. "We hope to be able to use this information to help people avoid serious health problems by changing their diet to personalize their gut microbiome."