Immunomodulatory Effect and Biological Significance of β-Glucans

β-glucan, one of the homopolysaccharides composed of D-glucose, exists widely in cereals and microorganisms and possesses various biological activities, including anti-inflammatory, antioxidant, and anti-tumor properties. More recently, there has been mounting proof that β-glucan functions as a physiologically active “biological response modulator (BRM)”, promoting dendritic cell maturation, cytokine secretion, and regulating adaptive immune responses—all of which are directly connected with β-glucan-regulated glucan receptors. This review focuses on the sources, structures, immune regulation, and receptor recognition mechanisms of β-glucan.