The gut microbiota form a major interface between a significant proportion of the food we consume and the benefits we derive from its consumption.  Our food not only contains macro and micronutrients which are directly absorbed in the proximal small intestine, but it also contains so called prebiotics, large molecules which cannot be metabolized and absorbed by our small intestine, but are metabolized by the trillions of microbial organisms in our gut into thousands of absorbable molecules which can signal throughout our bodies, including the brain.  These prebiotics are mainly made up by plant derived fibers, in addition to large molecules called polyphenols and anti-inflammatory substances, contained in many health promoting foods, including olives, berries, cacao, turmeric and ginger. Thus when we eat a meal we both feed our body, as well as the microorganisms that live inside of our intestine. Many biological processes considered important for gut and overall health are dependent on a diet which increases the diversity and abundance of the gut microbes. Diets high in plant based fiber, such as the traditional Mediterranean or the MIND diet prevent leakiness of the gut and systemic low grade inflammation and have shown to be associated with health benefits for a variety of common chronic disorders including metabolic syndrome, colon cancer, cognitive decline, and depression.   The growing awareness of this gut microbial dimension of food with health benefits way beyond traditional nutritional benefits, has led to an increased focus of predominantly plant based diets as a prophylactic and therapeutic intervention for many chronic diseases of the developed world.