A probiotic, non-colonizing yeast species closely related to Brewer"s yeast and not related to the yeast group to which Candida belongs. Saccharomyces boulardii taken orally produces lactic acid and some B vitamins as it becomes established. During use, friendly probiotic bacteria are allowed to colonize in the GI tract making Saccharomyces boulardii particularly beneficial in balancing intestinal microbiology.* It is then eliminated after supplementation is stopped. It also has been shown to support production of secretory IgA.*