Simple daily habits make a difference. What you eat can change the microbes that live in your body. High-fiber foods (such as veggies, whole grains, and fruit) feed the helpful bacteria in your colon. They also discourage the growth of some harmful ones. Probiotic foods, such as yogurt and pickled vegetables, also deliver helpful bacteria to your gut. Getting enough sleep, easing stress, and exercising may also improve your microbiome.