Gut health describes the function and balance of the trillions of bacteria that live in our gastrointestinal tract. Gut bacteria have a number of important functions, such as breaking down food, producing vitamins, and helping our immune system, and imbalances in gut bacteria have been linked to a series of health issues, including obesity, mood disorders, and weakened immune response. Foods rich in fiber, prebiotics, and probiotics like fruits and vegetables, whole grains, and legumes, as well as fermented foods like yogurt, kefir, and sourdough, all support a healthy, balanced gut.