Ultimate Flora Probiotic from Renew Life contains 50 billion active probiotic organisms, which are natural residents of the healthy urogenital tract. This unique formula contains 45 billion Lactobacilli and 5 billion Bifidobacteria. Lactobacilli are the most prevalent beneficial bacteria found in the urogenital tract with lesser numbers of Bifidobacteria. Lactobacilli produce compounds and acids that help maintain a healthy balance of flora.