Unsaturated alginate oligosaccharides (UAOS) protects against dextran sulfate sodium-induced colitis associated with regulation of gut microbiota

Ulcerative colitis (UC) is highly correlated with the perturbation in gut microbiota. In our previous study, unsaturated alginate oligosaccharides (UAOS), enzymatic degradation products of alginate, showed great effect on obesity prevention through regulation of gut microbiota. The aim of this study was to investigate the ameliorative effect of UAOS in UC induced by dextran sulfate sodium (DSS) on mice models and further investigated its underlying mechanism. Herein, the results showed a dramatic alleviation of inflammatory reaction after UAOS supplement. Subsequent analyses showed that the community structure of gut microbiota changed. The abundance of phylum Firmicutes and Actinobacteria increased, while that of phylum Bacteroidetes decreased. Moreover, the balance renovation of the anti-inflammatory flora and pro-inflammatory flora is highly correlated with the alteration of host immune reaction. These results indicate that the protective effects of UAOS treatment attributes to the maintenance of the mucosal barrier function and inhibition of immune injury by regulating the gut microbiota.