Dietary maitake mushroom supplementation with the Y10M strain was associated with fewer cumulative days of selected URTI-related symptoms and modulation of antiviral innate immune responses in healthy adults, with effects that differed by strain and age cohort.
Overall incidence of upper respiratory tract infection episodes did not differ between maitake-supplemented and placebo groups.
Y10M maitake strain supplementation was associated with fewer cumulative days of fever and runny nose in both age groups.
Y10M maitake supplementation was associated with fewer cumulative days of sore throat in young adults specifically.
Y10M supplementation was associated with increased plasmacytoid dendritic cell frequency in middle-aged/older adults.
Y10M supplementation was associated with activation of conventional dendritic cells in middle-aged/older adults.
Y10M supplementation was associated with upregulation of type I interferon-related gene expression and IL12A following ex vivo stimulation in middle-aged/older adults.
The study enrolled healthy young adults (18-20 years) and middle-aged/older adults (40-85 years) with differing supplementation durations.
The rationale for studying maitake supplementation was based on age-related declines in innate immunity increasing the burden of upper respiratory tract infections.
This research suggests that eating bread supplemented with a specific strain of maitake mushroom (called Y10M, derived from Grifola frondosa) daily for several weeks may reduce the number of days people experience certain cold and respiratory illness symptoms, such as fever, runny nose, and sore throat, compared to eating a placebo bread. The study tested two different maitake strains (Y10M and C5304) in two age groups — young adults aged 18-20 years for 11 weeks, and middle-aged to older adults aged 40-85 years for 18 weeks — and found that only the Y10M strain showed these symptom-related benefits, while the C5304 strain had limited effects. Notably, neither maitake strain reduced the total number of respiratory illness episodes; rather, the benefit appeared in reducing how many days certain symptoms lasted when illnesses did occur. For middle-aged and older adults specifically, Y10M supplementation was also linked to measurable changes in the immune system, including increases in a type of immune cell (plasmacytoid dendritic cells) that is important for fighting viruses, activation of another type of immune cell (conventional dendritic cells), and increased activity of genes involved in the body's antiviral defense system (type I interferon pathway) and an immune signaling molecule called IL-12A. These immune changes were observed using laboratory tests on participants' blood cells after the supplementation period. This research suggests that the specific strain of maitake mushroom used in a supplement matters, and that regular dietary consumption of the Y10M strain may have a modest beneficial effect on both respiratory symptom burden and underlying antiviral immune function, particularly in older adults whose immune defenses naturally decline with age.
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Upload Your LabsMasuda Y, Nakayama Y, Shimizu R, Jogi E, Kato M, Yamasaki K, et al.. (2026). Maitake mushroom supplementation modulates upper respiratory symptoms and immune responses in healthy adults: a randomized, double-blind, placebo-controlled trial.. Food & function. https://doi.org/10.1039/d6fo01593j