Beta Glucan is found in several forms from a variety of natural sources. They are all polysaccharides or sugar molecules. Beta-1,3/1,6-D-Glucan is derived from Baker's yeast (Saccharomyces cerevisiae) and mushrooms like the maitake mushroom. This insoluble fiber has been studied for more than 30 years and found to support immune system function. As a dietary supplement, take one Vcap daily.