bananagirl
I think you mean MOS. This is the ingredient in S. Boulardii:
Bio-MOSĀ® [derived from S. cerevisiae, source of MOS (MannanOligoSaccharides)] 200 mg *
Sac. cerevisiae is a species of yeast.
(You can google or bing any ingredient you're not sure of.)
I had no trouble with Jarrow.