Dietary Lycium barbarum Polysaccharides Support Retinal Redox Homeostasis Through Gut Microbiota-Associated Metabolic Modulation.

Dietary polysaccharides are important bioactive components of functional foods and play a key role in modulating host metabolism through interactions with the gut microbiota. Lycium barbarum polysaccharides (LBP) are widely consumed as dietary supplements; however, their nutritional relevance in linking gut microbiota-associated metabolic regulation to extra-intestinal tissue homeostasis remains incompletely understood. In this study, we investigated the effects of dietary LBP intake on gut microbiota composition, metabolic profiles, and retinal redox status using oxidatively stressed 661W photoreceptor cells and rd10 mice. In vitro, LBP exposure was associated with reduced intracellular reactive oxygen species accumulation and enhanced cellular antioxidant capacity under oxidative stress conditions. In vivo, dietary LBP intake was associated with partial preservation of retinal structural parameters, including outer nuclear layer thickness and retinal vascular features. Integrated 16S rRNA gene sequencing and untargeted metabolomics analyses demonstrated that dietary LBP intake was associated with coordinated modulation of gut microbiota composition and microbial-derived metabolic pathways, particularly those related to pantothenate and coenzyme A biosynthesis, aromatic amino acid metabolism, and aminoacyl-tRNA biosynthesis. These metabolic alterations were reflected in retinal metabolic profiles and accompanied by improved redox balance. Overall, this study highlights the nutritional significance of LBP as a functional polysaccharide and supports the concept that dietary modulation of gut microbiota-associated metabolism may contribute to maintaining retinal metabolic homeostasis. These findings provide a nutritional and food science perspective on the potential role of dietary polysaccharides in supporting tissue function beyond the gastrointestinal tract.