Reishi mushroom (Ganoderma lucidum) has been traditionally used in East Asian medicine for its purported health benefits, including immune modulation and anti-inflammatory effects. In recent years, there has been growing scientific interest in its potential role in managing inflammatory bowel disorders (IBD) such as Crohn’s disease and ulcerative colitis. Preclinical studies, mainly in animal models, have shown that reishi extracts may reduce colonic inflammation, modulate cytokine production, and improve oxidative stress markers. The polysaccharides and triterpenes found in reishi are thought to be the primary bioactive compounds responsible for these effects.

For example, several rodent studies have demonstrated that reishi extracts can decrease disease severity in experimental colitis models, likely through suppression of pro-inflammatory cytokines (such as TNF-α and IL-6) and enhancement of antioxidant defenses. In vitro studies also support these immunomodulatory effects. However, robust clinical evidence in humans is lacking. Only a handful of small pilot studies and case reports have assessed reishi’s effects in IBD patients, with inconclusive results.

In summary, while there is some promising preclinical evidence suggesting a potential benefit of reishi mushroom in the management of IBD, high-quality human clinical trials are needed to confirm its efficacy and safety. Therefore, the current scientific evidence supporting reishi for IBD is limited and best considered preliminary.