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.