Chlorogenic acid enhances gut microbiota regulatory effect and anti-inflammatory of Lycium barbarum polysaccharide by simulated fermentation

The intricate interplay between dietary components, the gut microbiome, and host immunity is a core of intestinal immune research . Lycium barbarum polysaccharide (LBP)-chlorogenic acid (CGA) complex exhibits proliferative activity of Bacteroides and strong inhibitory effect on Staphylococcus aureus, but lacks of the microbial fermentation characteristics and immunomodulatory effect. Herein, in vitro fecal bacteria microbiota and macrophages models were employed to investigated the regulatory capacity of the LBP-CGA complex on intestinal microbiota and immunomodulatory activities of its metabolites. Results showed that LBP and LBP-CGA both readily fermentable. Fermentation led to significant molecular weight and pH reductions, nearly 85% polysaccharide degradation. Notably, LBP-CGA complex was more favorable to increase the relative abundance of Sutterella , Veillonella , Faecalibacterium and contents of SCFAs than LBP. Interesting, LBP fermentation product possessed the potential for immune-enhancing, with the polysaccharide fraction was the key active component. Conversely, LBP-CGA complex fermentation product elicited the potential for immune-suppressive response, with dihydrocaffeic acid of CGA metabolites was critical contributors. The data further indicated LBP-CGA exhibited better immunomodulatory of intestinal microbiota probably due to the proliferation of Bacteroides . Bacteroides may improve the bio-transformation of CGA and produce more dihydrocaffeic acid, which may in turn potentiate the immunosuppressive activity of the LBP-CGA complex fermentation product. To summarize, the results revealed that CGA elevated the ability of LBP to regulate the intestinal microbiota and to potential exert immunosuppression. This study offers profound insights into the development of LBP-CGA complex as a prebiotic with excellent anti-inflammatory effect.