Thousands of studies, spanning decades of research consistently show that encouraging the growth of healthy bacteria in the digestive tract could lower the risk for a wide variety of diseases, ranging from diarrhea to cancer. Beyond just supplying vital nutrients, some supplements and fermented foods including yogurt, contain live microbial food constituents, called probiotics, that when ingested exert health benefits. A strain of bacteria is only considered a probiotic if it survives the acidic environment of the stomach to exert healthful benefits in the intestine. Strains found to be most beneficial include Lactobacillus acidophilus, Bifidobacterium, and L. rhamnosus. Prebiotics are nondigestible food ingredients that encourage the growth of these healthful bacteria. In short, prebiotics are the food on which probiotics feed and multiply. Probiotic bacteria consumed with prebiotics that support their growth are called “synbiotics.”