Saccharomyces BoulardiiSaccharomyces boulardii is a health promoting probiotic yeast shown to support gastrointestinal health by boosting secretory IgA (sIgA) levels. sIgA is an immunoglobulin (protective antibody) that is found in the digestive tract and in mucosal secretions throughout the body. Maintaining healthy sIgA levels is crucial for supporting immune health, particularly in the GI system where there can be significant exposure to unwanted pathogens.