Objective: In this study, we evaluated the safety of excessive intake of granular foods containing extract of cultured Lentinula edodes mycelia (L.E.M.) in healthy adult volunteers.
Methods: Eleven subjects (8 males and 3 females, ages 33.4 ± 9.4) consumed the test foods containing 5,400 mg L.E.M. a day, three times the recommended daily intake, for 4 weeks.
Results: No adverse effect by excessive intake of test foods was observed in physical and clinical exam. No severe symptom was observed, except for mild gastrointestinal symptom such as soft stool in a subject who has hypersensitive intestine.
Conclusion: These results suggest that the granular food containing L.E.M. is safe in healthy adults, even if excessive amount up to 5,400 mg a day is consumed.

Lentinula edodes mycelia extract has been reported to maintain and improve immune function and QOL in cancer patients. In this study, the effects of Lentinula edodes mycelia extract on immune function were investigated in 10 healthy volunteers. Ten subjects were administrated Lentinula edodes mycelia extract orally for 20 weeks on average (846 mg / day ), and the immunological function (IFNγ production amount, IL-10 production amount, lymphocyte subset)was evaluated before and after ingestion at Fukuoka Tenjin Southern Clinic. Immune function following ingestion of Lentinula edodes mycelia extract showed a tendency of IFNγ production to increase, IL - 10 to decrease, and IFNγ / IL - 10 production ratio to be improved remarkably. No significant change was observed in lymphocyte subsets such as regulatory T cells before and after ingestion. Adverse events during the intake period were not observed. It was suggested that oral intake of Lentinula edodes mycelia extract has an action to improve the immune function of healthy adults.