Topic
This section collects materials on the effects of mushrooms and mycelial components on the immune system — from beta-glucans to extracts studied in clinical and preclinical research.
Beta-(1→3)-glucans with β-(1→6) side branches are the main structural polysaccharides of the basidiomycete cell wall. The review by S. P. Wasser, "Medicinal mushrooms as a source of antitumor and immunomodulating polysaccharides" (Applied Microbiology and Biotechnology, 2002), collects the material on the structural diversity of these compounds and their interaction with innate-immunity receptors — Dectin-1, CR3 and toll-like receptors. The effect depends not on the mere presence of the polysaccharide but on molecular weight, degree of branching and molecular conformation (triple helix versus unfolded chain).
For Trametes versicolor (Turkey Tail), PubMed indexes dozens of papers — predominantly by Japanese and Chinese authors — on the mycelium-derived fractions PSK (polysaccharide-K, "Krestin") and PSP (polysaccharide-peptide). These fractions are discussed as adjuvant-therapy agents for oncology patients and are included in approved protocols in Japan and China. In "Mycelium Running" (2005), Paul Stamets separately emphasizes that the results were obtained on specific strains and fractions, not on "mushrooms in general".
In the 2010s, a group led by Paul Stamets together with a Washington State University lab published a series of papers on the effect of mycelium extracts (Ganoderma lucidum, Fomitopsis officinalis, Trametes versicolor and other species) on viral load in honeybees infected with deformed wing virus (DWV). The effect was observed in limited samples and depended on concentration and delivery method; the protocols are analyzed in Fungi Perfecti materials.
Dosages, regimens and "protocols" are not given here — those data live in the primary sources, linked from the article cards below and on the "Sources" page. The texts deliberately separate laboratory data on specific fractions from the colloquial notion of "mushrooms for immunity" — these are different things, and Stamets himself points this out in lectures and in his materials on paulstamets.com.
More about the species behind much of the research in this section — in the mushroom catalog:
A review of Mohammed et al. (2026, The American Journal of Medicine) on mushroom supplements in oncology: reishi, trametes, cordyceps, maitake, agarikon, lion's mane, psilocybin. Which species have human evidence and where the base stays weak.
A consolidated review of clinical data on mushroom preparations in COVID-19: the FoTv mycelial blend (Fomitopsis + Trametes), agarikon, reishi, cordyceps, shiitake. From preclinical models to double-blind human RCTs.
Grifola frondosa, known as maitake, is one of the most studied medicinal mushrooms. Its beta-glucans, proteoglycans and D-fraction are studied for immunity, metabolism and adjuvant cancer therapy. A review of current data.
An overview of peer-reviewed research on mushroom beta-glucans: laboratory data, clinical work, and the limits of the evidence base.
Several independent groups have published data on the effect of mycelium extracts on viral load in honeybees. What is known today.
Current data on the bioactive substances of chaga (Inonotus obliquus): melanins, betulin, polysaccharides. Antioxidant and metabolic effects from preclinical and clinical work.
Current data on the clinical use of PSK and PSP polysaccharides from Trametes versicolor: adjuvant therapy for gastric cancer, colorectal cancer and other nosologies. The limits of the evidence base.