The regulation of intestinal microbiota and the intervention of Chinese herbal medicine in the treatment of ulcerative colitis

Background: The incidence of Ulcerative colitis (UC), a key form of inflammatory bowel disease (IBD) affecting the rectum and colon, is increasing globally. The advancement in microbiome and metabolomics research has revealed the crucial involvement of the intestinal microbiota in the pathogenesis and progression of UC. Chinese herbal medicines, characterized by structural diversity and multiple pharmacological activities, consistently serve as vital sources for developing anti-UC drugs. Methods: In this review, we searched and focused on several online databases, including the Web of Science, Science Direct, PubMed, and Google Scholar, using three keywords: “ulcerative colitis”, “intestinal microbiota”, and “Chinese herbal medicine” from 2013 to 2023. This review aims to uncover the mechanism of action of intestinal microbiota in the occurrence and development of UC and to explore the potential of Chinese herbal medicine in preventing and treating UC within the context of intestinal microbiota regulation. Results: This review summarizes the critical role of the intestinal microbiota in maintaining intestinal homeostasis by facilitating the repair of the intestinal epithelial cell barrier, modulating the immune system, and regulating pivotal metabolisms, including bile acids, amino acids, and short-chain fatty acids. Specifically, Chinese herbal medicines, comprising active ingredients such as polysaccharides, polyphenols, alkaloids, flavonoids, and terpenoids, as well as single Chinese herbal medicines and their extracts (extracts from Pulsatilla chinensis (Bunge) Regelcan, Ceandntella asiatica (L.) Urb., Heritiera littoralis fruit., and so on), and several combination preparations (for example, Ganluyin, Jiawei Gegen Qinlian Decoction, Baitouweng Tang), are capable of preventing and treating UC by regulating the gut flora. This, in turn, contributes to the repair of the intestinal epithelial barrier, modulation of the immune system, and regulation of those metabolisms. Conclusion: Overall, our study presents a timely and comprehensive review of the regulation patterns of intestinal microbiota in the treatment of UC and the intervention of Chinese herbal medicines by modulating intestinal microbiota. This work provides a further understanding of the pathogenesis of UC and a new perspective for understanding the “multi-dimensional” means of Chinese herbal medicine in treating UC.