Saccharomyces boulardii is a non-pathogenic yeast considered to be a probiotic. It is hardy, acid-tolerant, and thermotolerant.

History of Use
Saccharomyces boulardii was first discovered by French scientist Henry Boulard in 1923 from lychee and mangosteen fruit. S. boulardii is genetically and functionally distinct from brewer’s yeast (S. cerevisiae) and different from pathogenic candida species. By modern techniques, it has been found that S. boulardii is a unique strain or a variant of S. cerevisiae i.e. S. cerevisiae var boulardii.