What beta-glucans are
Beta-glucans are polysaccharides in which glucose monomers are linked by β-glycosidic bonds. Mushrooms predominantly contain beta-(1→3)-glucans with β-(1→6) branching, structurally distinct from cereal beta-glucans. The polysaccharide's structure largely determines its biological activity.
What studies have shown
In laboratory and animal models, mushroom beta-glucans displayed immunomodulating properties: they activated macrophages, increased cytokine production, and affected NK-cell activity. Human clinical work is sparse and often uses small samples, which makes generalization difficult.
What is important to keep in mind
- results depend on the glucan source, extraction method and dose;
- "immunomodulation" is a laboratory term describing an observed effect in cell and animal models;
- mushroom dietary supplements are marketed as food and functional products and are not registered as medicines.
More on reishi (Ganoderma lucidum) — one of the key beta-glucan sources in Stamets's materials — in the reishi species card.