I've been using Saccharomyces Boulardii for 26 years. I had C-Dif for a very long time and back then (1996) it wasn't available in the U.S. My Johns Hopkins doctor helped us get it from Germany but it was difficult with money conversion, translation and hoping customs officials would let it through. Thank God, it did (several times) and it literally saved my life! Not long after that it became available in the U.S. and I've been on this Jarrow kind ever since. Great stuff! It has kept me from having recurring C-Dif all of these years! I totally recommend it! Big thumbs up! Just FYI: I also take Primadophilus Bifidus too for my gut issues and they're excellent in conjunction with each other! I only wish it was less pricey but you do what you have to.....