Diet & Gut microbiota
The influence of diet on gut microbiota
Environmental factors—mainly lifestyle, diet and medication—outweigh the body’s genetics in determining the composition and proper functioning of the gut microbiota.
A diverse diet is considered a major factor in influencing your gut and the composition and function of the bacteria that live within it.
The idea that what you eat affects your health and that health starts in the gut isn’t new. Hippocrates, the father of medicine, suggested that “All disease begins in the gut”. Later, in 1907, Elie Metchnikoff was the first to hypothesize that replacing or diminishing harmful bacteria in the gut with lactic acid bacteria found in fermented foods could prolong life through a healthy gut.
Fast forward to the 21st century and scientists have learned that, although there’s a heritable component associated with the gut microbiota, environmental factors related to diet and drugs also have a major influence.
Recent studies have shown that a diet high in fat and sugar leads to changes in the gut microbiota that may explain the coincident increase in conditions such as type 2 diabetes, obesity, and inflammatory bowel diseases.
That’s why scientists recommend that a diet rich in microbiota-accessible carbohydrates (MACs)—abundant in whole grains, vegetables, legumes and nuts but lacking in processed foods—and exposure to fermented foods may be beneficial for preserving gut bacteria that are beneficial to human health. Beyond the well known effects of dietary fiber on gut health, other nutrients including carbohydrates, proteins, fats, vitamins, minerals and small compounds such as dietary polyphenols (with their antioxidant properties) can also act on the gut microbiota. In other words, the food you eat is the main fuel for your gut microbes.
With this in mind, the principle of “You are what you eat” is further clarified by science, which presents the alternative mantra of “You are what your gut microbes do with what you eat”.
Targeting the gut microbiota through diet not only matters in healthy people, but can also be added to medical treatment for conditions linked to lower bacterial diversity. In other words, maintaining a species-rich gut ecosystem through diet is a science-backed way to achieve a healthier lifestyle.
Another thing to consider is that not everyone responds to diet in the same way. And as gut microbiome responses to nutrition are specific to each individual, a “one-size-fits-all” dietary approach is being replaced by the idea of harnessing the potential of gut microbiome-informed personalized nutrition for better health.
- Within diet, prebiotics, fibers, probiotics and fermented foods have largely been studied as ways of keeping the gut microbiota in good shape and maintaining its capacity for resilience.