Saccharomyces boulardii is a probiotic yeast stain that survives passage through stomach acid and delivers its benefits to the intestinal tract. This strain helps protect and maintain a normal intestinal microflora, which in turn helps support intestinal health and immune response. It also works to restore the normal intestinal microflora when possible disruptions may occur, such as during the intake of certain medications and during travel. Saccaromyces Boulardii does not require refrigeration and cant be stored at room temperature. Refrigeration will, however, extend the shelf life. Avoid temperatures above 77F.