Effects of plant-derived polysaccharides on intestinal barrier function, immunomodulation, and gut microbiota: mechanisms and research advances
Owing to their excellent biocompatibility and diverse bioactivities, plant-derived polysaccharides have garnered increasing attention. As key dietary components, plant-derived polysaccharides have shown potential as nutritional interventions for supporting gastrointestinal health in various experimental models. This review systematically presents the latest insights into the multifaceted mechanisms of plant-derived polysaccharides over the past 5 years. Notably, inconsistencies among various experimental models regarding their effects on enhancing intestinal mechanical barrier function through the upregulation of tight junction proteins, modulation of host immune responses via cytokine regulation, and their role as prebiotics in improving beneficial gut microbiota and producing short-chain fatty acids are highlighted. This paper critically elucidates how monosaccharide composition, molecular weight, glycosidic bonds, and chemical modifications determine biological activity. Nonetheless, significant translational challenges persist: discrepancies exist between effective doses observed in animal models and their tolerability in humans, largely because of the lack of standardized protocols. A critical evaluation of these methodological differences and their implications for translational applications is necessary. Furthermore, we propose an integrated ‘crop-to-clinical’ perspective that links agricultural sourcing, processing stability, and clinical validation. Finally, this review emphasizes the necessity of rigorous quality assurance systems and analyses the complex global regulatory frameworks governing functional food applications.