Research Progress on the Role of Gut Microbiota–Intestinal Barrier Interaction in Ulcerative Colitis and Traditional Chinese Medicine Intervention
Ulcerative colitis (UC) is a chronic, non-specific inflammatory bowel disease with a continuously rising global incidence; an estimated 5 million cases were recorded worldwide in 2023, with emerging industrialized nations such as China showing the most pronounced increases. The core pathophysiological driver of UC's recurrent and refractory nature is a self-reinforcing vicious cycle between gut microbiota dysbiosis and intestinal barrier dysfunction. Reduced microbial diversity, depletion of beneficial taxa, and expansion of pathogenic bacteria disrupt short-chain fatty acid (SCFA) and tryptophan metabolism, impair the mucus layer, downregulate tight junction (TJ) proteins, and compromise immune barrier integrity, thereby exacerbating mucosal inflammation. Conventional therapies—aminosalicylates, glucocorticoids, immunosuppressants, and biologics—frequently fail to achieve durable remission and impose substantial economic burden. Traditional Chinese medicine (TCM), guided by the 'turbidity-toxin' theory, intervenes through multi-component, multi-target mechanisms: reshaping gut microbial composition, enhancing beneficial metabolite production, and upregulating TJ protein expression. This review systematically synthesizes the gut microbiota–barrier interaction in UC and the theoretical and modern biological mechanisms of TCM intervention, providing a theoretical reference for optimizing clinical strategies and highlighting the potential of TCM in UC management.