This product contains friendly bacteria. The digestive tract contains bacteria, or normal intestinal flora, that are necessary to maintain a balance in your colon and prevent the growth of pathogens, which are microorganisms that can cause illness and disease. These beneficial bacteria assist in the digestion of food and prevent many disorders such as candidiasis or yeast. The use of antibiotics, oral contraceptives and certain medications, as well as excess stress and a poor diet, can cause an imbalance in our digestive tract making it necessary to re-establish the normal flora. Each capsule of Olympian Labs Premium Acidophilus contains 5 billion viable organisms composed of Streptococcus Faccium, Lactobacillus Acidophilus and Bifidobacterium Longum. The cultures contained in these capsules are freeze dried under extremely gentle conditions and an important nutrition factor called FructoOligoSaccharides (FOS) is added. FOS nourishes the friendly bacteria and nourishes their growth. With FOS added, refrigeration isn't necessary.