Now Gr8-Dophilus is a combination of 8 different species of acid-resistant probiotic bacterial strains that are known to naturally colonize the human Gi tract. Probiotic bacteria are critical for healthy digestion. They help maintain the integrity of the intestinal lining, support proper intestinal motility and participate in the detoxification process. Gr8-Dophilus utilizes bacterial strains that have been clinically validated for their support of healthy immune system function. Fos is also included in this product to assist healthy growth of Acidophilus and Bifidus organisms.