Wikipedia
β-Glucans (beta- glucans) comprise a group of β-D-glucose polysaccharides naturally occurring in the cell walls of cereals, yeast, bacteria, and fungi, with significantly differing physicochemical properties dependent on source. Typically, β-glucans form a linear backbone with 1-3 β- glycosidic bonds but vary with respect to molecular mass, solubility, viscosity, branching structure, and gelation properties, causing diverse physiological effects in animals.
Various studies have examined the potential health effects of β-glucan. Oat fiber β-glucan at intake levels of at least 3 g per day can decrease the levels of saturated fats in the blood and may reduce the risk of heart disease. Some studies have suggested that cereal-derived β-glucan may also have immunomodulatory properties. Yeast and medicinal mushroom derived β-glucans have been investigated for their ability to modulate the immune system. β-glucans are further used in various nutraceutical and cosmetic products, as texturing agents, and as soluble fiber supplements, but can be problematic in the process of brewing.