Crataegus pinnatifida polysaccharide alleviates colitis via modulation of gut microbiota and SCFAs metabolism.

Inflammatory bowel disease (IBD) afflicted individual and most medications have side-effects. Crataegus pinnatifida (Hawthorn), which is a safe medicine and food homolog plant, has been reported to prevent colitis in murine. Yet the bioactivity component and the underlying molecular mechanism remain unclear. Here, we established a direct link between colitis induced by dextran sulphate sodium (DSS) in mice and polysaccharide HAW1-2 isolated from hawthorn. Our results showed HAW1-2 restored the pathological lesions in colon and inhibited the expression of inflammatory cytokines including IL-1β, IL-6 and TNF-α. Meanwhile, IKKα/β, IκBα, NF-κB and the phosphorylation levels were inhibited significantly. These findings suggested HAW1-2 could alleviate the inflammation of colon. Further, we found the composition of gut microbiota was modified and Bacteroides including Alistipes and Odoribacter were significantly enriched. Besides, we showed Alistipes and Odoribacter were positively co-related with acetic acid and propionic acid while were negatively co-related with inflammatory cytokines. Finally, we demonstrated the anti-inflammation activity of HAW1-2 might be induced by acetic acid. Together, the present data revealed HAW1-2 could directly modify the gut microbiota, especially for Bacteroides, and generate SCFAs to inhibit colitis. It also implies microbiota-directed intervention in IBD patients should be particularly given more attention.