High-fiber vegan diets promote healthful and stable gut bacteria, according to a review published in Frontiers in Nutrition. Increased intake of fiber and other plant components associated with plant-based diets increase the growth of beneficial bacteria that reduce inflammation and cardiovascular disease risk. Fiber also increases short-chain fatty acids linked to improved immunity and improved intestinal function. These conclusions indicate that diet contributes to healthful microbiome diversity more than any other factor, and a plant-based diet is the most effective means to ensure optimal gut health.
Tomova A, Bukovsky I, Rembert E, et al. The effects of vegetarian and vegan diets on gut microbiota. Front Nutr. Published online April 17, 2019.