The Structure–Decoding–Conversion–Effect Paradigm of Natural Polysaccharides for Gut Microbiota Remodeling in Ulcerative Colitis

. This structure-dependent microbial remodeling ultimately enhances the production of key metabolites and exerts comprehensive therapeutic effects, including repair of the intestinal barrier, suppression of excessive inflammation, and alleviation of oxidative stress, via activation of signaling pathways such as AMP-activated protein kinase (AMPK) and nuclear factor erythroid 2-related factor 2 (Nrf2) and inhibition of pathways such as nuclear factor kappa-B (NF-κB). By exploring the paradigm of "Structure-Decoding-Conversion-Effect" based on precise microecological regulation of polysaccharide structures, this paper provides a crucial theoretical foundation and design strategy for developing targeted microecological interventions.