Yeast glucan is a functional polysaccharide present in yeast cell walls, with β-1,3-D-glucan as the main chain and β-1,6-D-glucan as the branched chain, with a relative molecular mass of about 240,000 and about 10,000 glucose molecules connected.Yeast glucan has the functions of enhancing immunity, improving resistance to infection and disease, resisting radiation, and decreasing blood lipids.