Lentinula edodes (shiitake mushroom) mycelia have been investigated for their potential to support the treatment of hepatitis, particularly through the use of its purified polysaccharide, lentinan. There is a modest but growing body of scientific evidence supporting its use, primarily from research in Japan and China. Lentinan is known to possess immunomodulatory properties, enhancing the activity of macrophages, natural killer cells, and T-lymphocytes. These immune-boosting effects have been proposed as beneficial in viral hepatitis, where immune response modulation may help control the infection and limit liver inflammation.

Several preclinical studies (in vitro and in animal models) have shown that lentinan can inhibit hepatitis B virus (HBV) replication and may reduce liver damage markers. Some small clinical studies and case reports in humans have suggested potential improvements in liver function tests and decreased viral load in hepatitis B and C patients when used as an adjunct to conventional therapy. However, these studies are limited in size and methodological quality, and large, well-controlled clinical trials are lacking.

Overall, while there is some scientific validation for the use of Lentinula edodes mycelia and lentinan in supporting hepatitis treatment, the evidence is considered preliminary. The ingredient is not a primary therapy but may offer adjunctive benefits, particularly in modulating immune responses. More rigorous clinical research is needed to confirm efficacy and safety.