Non-Dairy Room Temperature Stable MannanOligoSaccharides Provides Enhanced Support to the Intestinal Tract Probiotic Supplement 5 Billion Per Capsule Vegan Jarrow Formulas Puts the "PRO" in ProbioticsSaccharomyces Boulardii + MOS is a probiotic yeast that survives stomach acid and colonizes the intestinal tract. It promotes the health of the intestinal tract, helps protect its beneficial microbiota, and enhances immune function. MOS (MannanOligoSaccharides) is an oligosaccharide from the cell walls of S. cerevisiae that can discourage bacteria from adhering to the epithelial cells and reduce their proliferation.