Beta Glucan

About Beta Glucan

Beta glucans are polysaccharides made of glucose units joined by beta glycosidic bonds, found in the cell walls of cereals such as oats and barley, as well as in fungi, yeast, algae and some bacteria. Cereal beta glucans are linear chains with mixed beta 1,3 and beta 1,4 linkages and form viscous solutions in the gut, behaving as soluble fiber. Fungal and yeast beta glucans have a beta 1,3 backbone with beta 1,6 branches and are recognized by immune receptors such as Dectin 1. Oat and barley beta glucans lower blood LDL cholesterol, an effect that underlies authorized health claims in the United States and the European Union; the mechanism involves increased viscosity of gut contents and greater excretion of bile acids. They also slow glucose absorption and blunt rises in blood sugar after meals. Mushroom derived beta glucans such as lentinan from shiitake and polysaccharide K from turkey tail have been used in Japan as adjuncts to cancer treatment. Yeast beta glucans have been studied for upper respiratory infections and immune function, with limited evidence.