Pectin as a Multifunctional Therapeutic Platform for Ulcerative Colitis: Integrating Colonic Targeting, Microbiota Remodeling, and Antioxidant Synergy

Ulcerative colitis (UC) is a refractory intestinal disease characterized by chronic colonic mucosal inflammation, oxidative stress imbalance, and gut microbiota dysbiosis. Existing drugs partially control inflammation but may not simultaneously achieve adequate colonic drug exposure, systemic safety, and sustained efficacy. Pectin, which resists gastric and small intestinal digestion yet is susceptible to degradation by colonic microbiota-derived enzymes, has emerged as a promising natural carrier for colon-targeted delivery. However, most studies have positioned pectin primarily as a drug carrier, with less emphasis on its potential microbiota-modulating and antioxidant activities as dietary fiber. Pectin may provide complementary functions: microbiota-mediated degradation can facilitate colonic drug release, fermentation-derived short-chain fatty acids (SCFAs) may contribute to gut microecological regulation and intestinal barrier integrity, and combination with antioxidants may enhance local antioxidant effects. This review summarizes the structure–activity relationships that link pectin’s fine structural parameters, including degree of esterification, galacturonic acid content, and homogalacturonan (HG)/rhamnogalacturonan-I (RG-I) ratio, to its colonic release kinetics, microbial metabolite profiles, and antioxidant efficacy. It further reviews the design evolution of pectin-based systems from single enzyme-responsive systems to pH–enzyme–ROS cascade release and discusses personalized carrier design guided by patient microbiota stratification for precision UC therapy. Although multifunctional effects have been reported in preclinical studies, their mechanistic interactions and clinical efficacy remain insufficiently established. This review highlights the potential of pectin as a multifunctional bioactive platform integrating colon-targeted delivery with complementary biological activities for UC therapy.