Supports the production of secretory IgA and intestinal immune responses Contains 500 mg (or 10 billion viable cells at the time of manufacture) of the non-pathogenic yeast Saccharomyces boulardii per serving. This strain does not require refrigeration and can survive passage through the harsh gastric environment, withstanding high acidity, bile, and heat. This strain has been extensively researched for its potential use in promoting gastrointestinal health.