Mushrooms exhibit both direct and indirect anti-fungal activity in vitro and in vivo1. The widely held belief that mushrooms somehow exacerbate candidal overgrowth runs contrary to scientific research, clinical experience and theoretical understanding. Not only do mushrooms stimulate the body’s anti-fungal immune response but in nature they need to compete for resources with other fungi, as well as other microorganisms, and so have evolved a range of powerful anti-fungal defences.

Lentinula edodes extracts and juice show strong anti-fungal action, as do aqueous
extracts of Pleurotus ostreatus, with 50% inhibition against C. albicans2-6. In addition, triterpenes from Ganoderma species show anti-fungal activity, while mice given a polysaccharide-rich extract of A. subrufescens showed enhanced candidacidal activity characterized by higher levels of H2O2 and increased mannose receptor expression by peritoneal macrophages (involved in the attachment and phagocytosis of non-opsonized microorganisms)7.

It has also been suggested that chitin present in mushroom cell walls may help prevent colonisation of the intestinal mucosa by candida species8. Trametes versicolor has traditionally been used inMexico to treat thrush and clinically is seen to reduce Candida overgrowth. PSK has also been shown to have a pronounced protective effect against lethal infection with C. albicans in mice. An injection of 250mg/kg 24 hours before inoculation of 1×106 C. albicans increased the 30 day survival rate by 60% and mean survival time by 209%9. Oral PSK supplementation of tumour bearing mice challenged with C. albicans also resulted in a prolongation of the mean survival period together with a reduction in fungal counts10.

While polysaccharides are responsible for potentiating the immune response, many anti-fungal compounds produced by mushrooms are excreted into the substrate and captured by mycelial biomass products. T. versicolor and L. edodes mycelia biomass products show good anti-candida activity (2-3g/day).

1. Antifungal secondary metabolites from fungal fruiting bodies. Dunek C, Volk TJ. Int J Med Mushr. 2007;9(3):227-228.
2. An examination of antibacterial and antifungal properties of constituents of Shiitake (Lentinula edodes) and oyster (Pleurotus ostreatus) mushrooms. Hearst R, Nelson D, McCollum G, Millar BC, Maeda Y, Goldsmith CE, Rooney PJ, Loughrey A, Rao JR, Moore JE. Complement Ther Clin Pract. 2009;15(1):5-7.
3. Antimicrobial properties of shiitake mushrooms (Lentinula edodes). Rao JR, Smyth TJ, Millar BC, Moore JE. Int J Antimicrob Agents. 2009;33(6):591-2.
4. Antagonistic effect of edible mushroom extract on Candia albicans growth. Paccola E, Maki CS, Nobrega GMA, Paccola-Meirelles L.D. Braz J Microbiol. 2001;32:3.
5. Antimicrobial and antineoplasic activity of Pleurotus ostreatus. Wolff ER, Wisbeck E, Silveira ML, Gern RM, Pinho MS, Furlan SA. Appl Biochem Biotechnol. 2008;151(2-3):402-12.
6. Antimicrobial action of Lentinus edodes juice on human microflora. Kuznetsov OI, Mil’kova EV, Sosnina AE, Sotnikova NI. Zh Mikrobiol Epidemiol Immunobiol. 2005;1:80-2.
7. Polysaccharide-rich fraction of Agaricus brasiliensis enhances the candidacidal activity of murine macrophages. Martins P.R, Gameiro M.C, Castoldi L, Romagnoli GG, Lopes FC, Pinto AV, Loyola W, Kaneno R. Mem Inst Oswaldo Cruz. 2008;103(3):244-50.
8. Fungal Chitin in medicine: prospects for its application. Ludmila IB, Leontij FG. Int J Med Mushr. 2001;3(2-3)126-127.
9. Protective effects of a protein-bound polysaccharide, PSK, on Candida albicans infection in mice via tumour necrosis factor alpha induction. Ohmura Y, Matsunaga K, Motokawa I, Sakurai K, Ando T. Int Immunopharmacol. 2001;1:1797-1811.
10. Protective effects of a protein-bound polysaccharide, PSK, against Candida albicans infection in syngeneic tumour bearing mice via Th1 cell functions. Ohmura Y, Matsunaga K, Motokawa I, Sakurai K, Ando T. Cancer Biother Radiopharm. 2003;18(5):769-8 .