What is beta-glucan?

Beta-glucan is a polysaccharide of sugar molecules and originates from natural sources: yeast, bacteria, fungi, mushrooms, oat, barley, and lichens. Not all beta-glucans are generated equal. Difference beta-glucans have a difference in health benefits. Oat and barley beta-glucans are known to be useful for heart health and dietary fiber, whereas yeast beta-glucans are beneficial for the immune system. We choose the cell wall of bakers yeast, Saccharomyces cerevisiae, which is an essential source of beta-glucan. All beta-glucans are glucose polymers linked together by a 1→ 3 linear beta glycosidic chain core, and they differ from each other by their length and branching structures. The branches derived from the glycosidic chain core are highly variable, and the two main groups of branching are 1→4 or 1→6 glycosidic chains. These branching assignments appear to be species-specific, such as beta-glucans of fungus and yeast have 1→6 side branches whereas those of bacteria have 1→4 side branches. After oral uptake, beta-glucans were taken up by macrophages via the Dectin-1 receptor and subsequently transported to the spleen, lymph nodes, and bone marrow. The large beta 1,3 glucan molecules are then internalized and fragmented into smaller sized beta 1,3glucan fragments within the macrophages. These fragments were afterward taken up via the complement receptor 3 (CR3) of the circulating granulocytes and monocytes. The immune response will then be turned on. The reactor cells involve monocytes, macrophages, dendritic cells, natural killer cells, and neutrophils. The immunomodulatory functions induced by beta-glucans affect both innate and adaptive immune response. Beta-glucans also increase opsonic and non-opsonic phagocytosis and trigger a cascade of cytokines releases, such as tumor necrosis factor(TNF)-alpha and numerous types of interleukins (ILs).