Good bacteria for your gut? Probiotics are "friendly" bacteria found in the gut that help us digest foods and fight harmful bacteria. They also include live, active cultures used to ferment foods, such as yogurt. Interested in getting the potential benefits offered by probiotics? Mix a cut-up banana into a cup of low-fat vanilla yogurt—a brand with a "Live & Active Cultures" seal—for a midday snack or turn it into breakfast and add some granola. Try different kinds of yogurt to see which one works best for you.