Probiotics are good bacteria that help support gastrointestinal health. Nature's Way Fortify Women's Probiotic is formulated with a higher ratio of lactobacilli: inluding 26 billion lactobacilli and 4 billion bifidobacteria. It contains researched strains NCFM, Bi-07, La-14, HN019 and HN001. Fortify's 30 billion potency of live probiotic cultures is guaranteed until product expiration date when stored under recommended conditions. Nature's Way Fortify Women's Probiotic is vegetarian, non-GMO verified and TRU-ID certified.