Shiitake mushrooms (Lentinula edodes) have a long history of use in traditional Asian medicine, but their application for inflammatory bowel disorders (IBD), such as Crohn’s disease or ulcerative colitis, is primarily supported by emerging scientific research rather than strong traditional precedent. Recent preclinical studies have demonstrated that shiitake mushrooms contain bioactive compounds—most notably beta-glucans, polysaccharides, and eritadenine—that exhibit anti-inflammatory and immunomodulatory effects. Animal models of colitis have shown that shiitake extracts can reduce inflammation, decrease pro-inflammatory cytokines, and improve histological signs of colonic damage. For example, several rodent studies report that dietary supplementation with shiitake mushroom powder or extracts can ameliorate symptoms such as weight loss, colon shortening, and mucosal injury in chemically induced colitis models.

However, direct evidence in humans with IBD is very limited. The majority of published data comes from in vitro or animal studies, and there are currently no robust clinical trials validating shiitake’s efficacy in IBD patients. Thus, the use of shiitake mushrooms for IBD is justified by early scientific validation, primarily from non-human research, rather than strong traditional use or high-quality clinical evidence. More research, especially well-designed human studies, is needed to confirm safety and therapeutic benefit in this context.