I do not know- it was prescribed by a physician after I finished the antibiotic treatment for C- Dif. I feel better than I have in a number of years. It was prescribed for two months. I plan to take it every 6-8 months to keep my colon healthy. In the interim I will take other broad spectrum probiotics.
I hope this helps you.
Florastor contains only our single, unique probiotic strain Saccharomyces boulardii CNCM I-745 and as for the CFU's, this link on our website might be helpful- https://florastor.com/cfu/ ! -The Florastor Team