S Boulardii is short for Saccharomyces Boulardii. For this article we’ll refer to it as SB. It is a yeast that has been shown to combat the effectcs of C Diff in multpile studies.
According to studies, it can actually digest toxins A and B. In this study, the researchers “conclude that the protective effects of S. boulardii on C. difficile-induced inflammatory diarrhea in humans are due, at least in part, to proteolytic digestion of toxin A and B molecules by a secreted protease.”
Dosage and Relapse Reduction
Studies now show that Saccharomyces Boulardii to your treatment regime can dramatically reduce your risk of relapse. In at least one study we see the risk of relapsing go down from 50% to 16%! This study had patients using a dose of 1g of Saccharomyces Boulardii for 28 days . So if you were to take the same dosage in Florastor 250mg pills (http://www.florastor.com/article9fa1.html?id=2164) you’d take 4 pills per day. I took a dose a little higher, but you’d be safer to stick with proven doses.
You can get Saccharomyces Boulardii online at http://www.rockwellnutrition.com/product.asp?itemid=783
 Surawicz CM, McFarland LV, Greenberg RN, Rubin M, Fekety R, Mulligan ME, Garcia RJ, Brandmarker S, Bowen K, Borjal D, Elmer GW. The search for a better treatment for recurrent Clostridium difficile disease: use of high-dose vancomycin combined with Saccharomyces boulardii. Clin Infect Dis. 2000 Oct;31(4):1012-7. Epub 2000 Oct 25. Site: http://www.ncbi.nlm.nih.gov/pubmed/11049785 last visited Aug 23 2009.