Different regulatory effects of Lycium barbarum polysaccharide components on gut microbiota in vivo and in vitro

Lycium barbarum polysaccharides (LBPs) are valuable plant-derived compounds with diverse biological activities. Herein, the digestive characteristics of different LBP components (CLBP, LBP1, LBP2, and LBP3) and their enzymatic behavior were investigated through artificial simulated gastrointestinal digestion and in vitro fermentation. Moreover, the metabolic status of different LBP components and their regulatory effects on gut microbiota and short - chain fatty acids (SCFAs) were explored in mice. The results showed that a small fraction of polysaccharides degraded under simulated gastrointestinal conditions and the different LBP components differentially reshaped gut microbiota composition and SCFAs production in vitro and in vivo . Particularly, LBP3, a well-defined component of L. barbarum arabinogalactan, possesses potent immunomodulatory activity, significantly increased the relative abundances of Bifidobacterium pseudolongum , Akkermansia muciniphila , Lactobacillus reuteri , and Bacteroides acidifaciens , and reduced the relative abundances of Cutibacterium acnes and Burkholderiales bacterium YL45 . Furthermore, it significantly increased acetic and propionic acids concentrations to a greater extent than other components did. Our findings provide a theoretical basis to further explore the bioactive mechanisms of LBPs and offer new insights into developing healthy functional foods with arabinogalactan structures.