There is strong evidence for a link between the foods a person eats, the microbes that live in the person's gut (gut microbiome), and the person's health, according to a large international study. Yes, it's all related.
The researchers were able to find clear patterns of the types of foods eaten and the microbes in the gut. They found that the presence of 15 specific bacteria are consistently associated with good health ("good microbes") and some other bacteria ("bad microbes") are associated with poor metabolic health (including inflammation, blood sugar control).
Study researcher Tim Spector (of King's College London) said: "When you eat, you're not just nourishing your body, you're feeding the trillions of microbes that live inside your gut."
They found that a diverse diet rich in minimally processed plant-based foods (e.g. fruits, vegetables, seeds, nuts, whole grains, dietary fiber) and fish supports and feeds "good" gut microbes associated with health, with favorable blood sugar levels (glucose control), lower levels of inflammation, improved metabolism, and thus lower risk of heart disease and other chronic conditions (e.g. type 2 diabetes).
On the other hand, persons that ate more highly processed foods, added sugars (desserts!), low fiber foods, artificial sweeteners, foods with additives were more likely to have "bad" microbes linked to poor health, inflammation, unfavorable blood sugar levels, and obesity.
They were able to see that specific foods clearly had an effect on specific bacteria, for example eating tomatoes with an increase in beneficial species of Roseburia. Eating a variety of plant based foods was also associated with an increase in diversity of bacteria (this is considered good), and also with the presence of beneficial keystone bacteria such as Faecalibacterium prausnitzii.
VERY IMPORTANT: The beneficial bacteria the researchers list are NOT in probiotic supplements. Instead, you must eat a variety of foods that feed beneficial bacteria (e.g. eating a Mediterranean style diet). In fact, some of the microbes the researchers found have not yet been named. Foods also contain bacteria, and these are ingested. For example, an apple contains about 100 million bacteria!
From Science Daily: Link between gut microbes, diet and illnesses revealed
Diets rich in healthy and plant-based foods encourages the presence of gut microbes that are linked to a lower risk of common illnesses including heart disease, research has found.
A large-scale international study using metagenomics and blood chemical profiling has uncovered a panel of 15 gut microbes associated with lower risks of common conditions such as obesity and type 2 diabetes. The study has been published today in Nature Medicine from researchers at King's College London, Massachusetts General Hospital (MGH), Harvard T.H. Chan School of Public Health, the University of Trento, Italy, and health start-up company ZOE.
The PREDICT 1 (Personalized Responses to Dietary Composition Trial 1) analyzed detailed data on the composition of participants' gut microbiomes, their dietary habits, and cardiometabolic blood biomarkers. It uncovered strong links between a person's diet, the microbes in their gut (microbiome) and their health.
Researchers identified microbes that positively or negatively correlate 'good' and 'bad' with an individual's risk of certain serious conditions such as diabetes, heart disease and obesity. Surprisingly, the microbiome has a greater association to these markers than other factors, such as genetics. Some of the identified microbes are so novel that they have not yet been named.
The researchers defined a "healthy" diet as one that contained a mix of foods associated with a lower risk of chronic disease. They found that trial subjects who ate such a diet, or one rich in plants, were more likely to have high levels of specific 'good' gut microbes which are associated with a low risk of common illnesses. The researchers also found microbiome-based biomarkers of obesity as well as markers for cardiovascular disease and impaired glucose tolerance, which are key risk factors for COVID. These findings can be used to help create personalized eating plans designed specifically to improve one's health.
For example, the findings reveal that 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.
Nicola Segata, PhD, professor and principal investigator of the Computational Metagenomics Lab at the University of Trento, Italy and leader of the microbiome analysis in the study, said: "We were surprised to see such large, clear groups of what we informally call 'good' and 'bad' microbes emerging from our analysis. It is also exciting to see that microbiologists know so little about many of these microbes that they are not even named yet. This is now a big area of focus for us, as we believe they may open new insights in the future into how we could use the gut microbiome as a modifiable target to improve human metabolism and health."