Probiotics are live beneficial bacteria that can contribute to gut health by supporting the balance of gut flora, found in fermented foods and supplements. Prebiotics, on the other hand, are non-digestible fibers that feed these beneficial bacteria, promoting their growth and activity, and are found in foods like bananas, onions, garlic, and whole grains. Essentially, probiotics add to the population of good bacteria in the gut, while prebiotics provide the food needed to nourish and increase those beneficial bacteria.