beta13glucan

Beta-1,3-glucan is a polysaccharide of D-glucose units linked by beta-1,3 glycosidic bonds. In many fungi and yeasts, beta-1,3-glucan is a major structural component of the cell wall, forming a network that can include beta-1,6 branches in some forms. When branching occurs, the molecule is sometimes described as beta-1,3/1,6-glucan; branched glucans vary in solubility and biological activity.

Natural sources include fungal species such as Saccharomyces cerevisiae and edible mushrooms such as shiitake and maitake, and related beta-glucans are also produced by some bacteria (curdlan). Beta-1,3-glucans are used as dietary fibers in foods and supplements.

Beta-1,3-glucans are recognized by pattern recognition receptors of the innate immune system, notably Dectin-1 and complement receptor 3 (CR3). This interaction can stimulate macrophages, neutrophils, and natural killer cells and modulate cytokine production. Immune effects observed in preclinical and some clinical studies have spurred investigation into infection prevention, anti-inflammatory effects, and cancer therapy as an adjunct, though results are variable and depend on structure, dose, and source.

Beta-1,3-glucans are used as dietary supplements and, in some countries, as adjuvants in cancer treatment or in traditional medicine. They are generally regarded as safe when consumed as food or supplements, but high doses may cause gastrointestinal symptoms and may interact with medications or immune conditions.