By Dr. Frank Sabatino

There is a vast, teeming world of trillions of microorganisms living within you that are essential to life and health. Several pounds of these creatures live in the intestine and are referred to as the gut microbiota/microbiome (GM). Extensive research continues to reveal that the diversity and activity of the GM plays an important role in health and disease: including overall nutrition, the function and regulation of the immune system/inflammation, mood and mental health, cardiovascular health, the metabolism of estrogen and cholesterol, satiety and eating behavior, and even cancer. 

Diet shapes the GM from birth to adulthood. The integrity of the immune system is established in the earliest days of  life. Breastfed babies that are born vaginally have a greater diversity of their GM, and healthier immune systems, including more healthy bifidobacteria and the protective antibody, secretory IgA, than bottle fed babies born by C-section. 

The GM requires fiber as a prebiotic nutrient. Unfortunately, since the typical American diet is less than 5 percent fresh fruits and vegetables, and predominantly fiber poor ultra-processed food and animal products,  we can make the case that fiber is the most important deficiency of the modern diet. Children and adults who eat diverse high-fiber, plant-based diets have a diversity and number of GM species that are significantly more health promoting than people eating low-fiber highly processed animal-based diets. It is the diversity of the GM , promoted by high-fiber plant foods that determines a healthy, functioning GM.

High-fiber plant foods including cruciferous vegetables, oatmeal, bananas, berries, whole grains, beans, lentils, potatoes, onions , nuts, and seeds, provide soluble fiber and resistant starch that is transported to the colon where it is fermented by the GM to produce short-chain fatty acids ( butyrate, propionate) that help produce the mucous layer that lines and protects cells of the colon. This mucous lining provides a  barrier that is the first line of protection of your innate immune system, and protects the cells of the colon  from toxin exposure that can promote irritation, inflammation , chronic cell damage and even colon cancer. 

Low fiber diets loaded with meat, dairy, refined sugar, salt and oil , in addition to chronic stress hormones, alcohol, antibiotic abuse, and herbicides like glyphosate, are gut disruptors that can damage a healthy, balanced, probiotic GM and create dysbiosis . This causes an over growth of inflammatory, toxic organisms as well as a breakdown  in the normal protective lining of the gut. The resulting increase in intestinal permeability, can allow larger protein fragments , toxic by-products of digestion, and bacterial toxins to infect cells of the colon and incite the immune system to promote inflammation, potential allergies, and even autoimmune diseases like rheumatoid arthritis.

Diets high in red meat, fish and eggs are high in choline and L-carnitine. There are more than nine different species of bacteria in the GM that convert these chemicals into the compound TMAO that increases the risk of atherosclerosis (1) and other adverse cardiovascular events including heart attacks, blood clots, stroke and death.(2) People on high-fiber plant-exclusive diets produce significantly less TMAO. In addition, when the GM receives the fiber it needs, it can convert circulating cholesterol into the insoluble compound coprastanol that is eliminated in the feces thereby reducing the re-circulation of cholesterol and lowering the risk of heart disease. 

There is mounting evidence for communication between the GM and the brain. Irritation and inflammation in the gut, can signal and trigger mood changes and psychological disturbances in the brain. Dysbiosis of the GM can provoke the release of inflammatory cytokines and bacterial toxins that damage the brain’s protective barrier to increase brain toxicity and promote anxiety, depression and memory loss.

High-fiber plants also promote the production of GM metabolites that affect gene expression and cancer risk. Specifically, The GM produces isothiocyanates similar to the cruciferous vegetables broccoli, cauliflower and Brussels sprouts , and polyphenols (catechins, tannins and isoflavones) similar to berries, walnuts, pomegranates, green tea and soybeans that have been shown to epigenetically modify the structure and expression of genes in the cells of the colon to inhibit and kill cancer cells in the colon. (3)

To enhance the probiotic environment of your gut, a few ounces of fermented foods, including tempeh and low salt sauerkraut, can be consumed a few times a week. To increase beneficial resistant starch, make extra potatoes that you can keep in the fridge to eat cold over the next few days. You can make a potato salad with these leftovers with lemon juice, red onions , celery , peppers and dill  and its a delightful way to enhance the GM. 

Always keep in mind that the whole plant-exclusive diet is in your best health interest and the best way to nurture your magical world within.

References

1. Wang Z et al. Prognostic value of choline and betaine depends on intestinal microbiota-generated metabolite trimethylamine-N-oxide. Eur Heart J. 2014;35(14):904-910.

2. Koeth RA et al. Intestinal microbiota metabolism of L-carnitine, a nutrient in red meat, promotes atherosclerosis. Nat. Med. 2013;19(5):576-585.

3. Hullar MA and Fu BC. Diet, the gut microbiome, and epigenetics. Cancer J. 2014;20(3):170-175