Gut microbiota-mediated therapeutic mechanisms of Dendrobium officinale polysaccharide: A review

Dendrobium officinale polysaccharide (DOP) functions as a prebiotic that ameliorates multiple diseases through selective modulation of the gut microbiota. Its structural features-including molecular weight profile, mannose/glucose ratio, and β-(1 → 4)-glucomannan backbone-program a dual-mode ecological action: serving as a broad fermentable substrate to produce short-chain fatty acids (SCFAs), while enabling precise bacterial selection via polysaccharide utilization loci and specific glycoside hydrolases (e.g., GH26 mannanase). This structure-guided remodeling enriches beneficial taxa (e.g., Akkermansia, Parabacteroides), rebalances the Firmicutes/Bacteroidetes ratio, and enhances microbial production of bioactive metabolites such as SCFAs and neurotransmitters. These metabolites, in turn, mediate systemic therapeutic benefits across metabolic, neurodegenerative, immune-related, and mood disorders, as well as cancer, primarily by strengthening intestinal barrier function, regulating GPCR41/43 and TLR4/NF-κB signaling, and attenuating inflammation. This review positions DOP as a structure-guided ecological modulator and highlights potential for use in developing precision prebiotics and microbiota-targeted functional foods.