IDDF2021-ABS-0197 Delayed intervention of agaropectin-derived oligosaccharides alleviate lipid accumulation by modulating intestinal flora homeostasis

Background Polysaccharides from marine red algae possess a variety of biological activities. And, our previous study illustrated that the agaropectin-derived oligosaccharides from Gloiopeltis furcata (SAOs) activated AMPK signaling pathway in vitro. However, the effects of SAOs on alleviating lipid accumulation in vivo and its underlying mechanism are not clear. Methods C57BL/6J mice were randomly divided into five groups of ten mice each. Control group: mice were fed a normal chow diet. And, the other four groups were continuously fed an HFD for 24 weeks to establish the obesity model. After 24 weeks, the Metf, SAOs-L, and SAOs-H groups received either metformin (225 mg/kg/d dissolved in saline) or SAOs (100 or 300 mg/kg/d dissolved in saline), while the Control and Model groups were given aliquots of saline. Saline and the drugs were given by oral gavage for the final six weeks of the experimental period. Results We found that SAOs decreased the body weight (about 3 grams) and the adiposity index (from 7 to 5) after a 6-week treatment. In addition, SAOs alleviated lipid accumulation in the liver, perirenal fat, and epididymal fat tissues. Investigation of the underlying mechanism showed that the cecal microbiota dysbiosis in HFD-fed mice were ameliorated after SAOs treatment, including significantly increasing the relative abundance of Alistipes, while reducing the relative abundance of Helicobacter. In addition, Spearman’s correlation analysis indicated that changes in the cecal microbiota could regulate lipid accumulation, oxidative stress, inflammation. Conclusions The present study confirmed that SAOs could effectively alleviate HFD-induced fat accumulation, partly through regulating cecal microbiota by fostering the preferential growth of probiotics and suppressing the relative abundance of harmful bacteria. In summary, our study illustrated that SAOs could be further developed as a potential pharmaceutical agent for obesity.