Consumption of Lentinula edodes modulates human immune function by altering cytokine secretion of PBMC ex vivo

Abstract

Lentinus edodes (Shiitake) is a medicinal mushroom with a long tradition of use in Asia. The literature suggests that mushrooms modulate immune function, but there have been no controlled studies of Shiitake mushroom consumption on the human immune response. Therefore, we recruited 51 healthy adults, who were randomly allocated to consume either 50g/d or 100g/d of dried, whole Shiitake mushrooms for 28d. Peripheral blood mononuclear cells (PBMC) were isolated and cultured for 24hr with PHA‐L. Culture media was harvested and analyzed for cytokines by multiplex technology. There was no significant difference between the two serving sizes, so the data was pooled and analyzed by paired t‐test. After 28d of Shiitake mushroom consumption, secretion levels of IL4 (51.4%, p<0.001), IL10 (33.4%, p<0.001), IL1α (16.6%, p=0.015) and TNFα (16.6%, p=0.009) by PBMC were significantly increased, while IL6 (−41.0%, p<0.001) and MIP1α (−67.4%, p<0.001) levels were significantly reduced, compared to those seen before consumption. Secretion levels of other cytokines, IL1β, IL17, MIP1β and IFNγ, were the same before and after consumption. These results show that supplementing the diet with whole Shiitake mushrooms is immuno‐modulatory, as seen by the altered pattern of cytokine secretion by stimulated PBMC ex vivo. Funded by US Mushroom Council; Australian Mushroom Growers Assn.