Portulaca oleracea polysaccharide alleviates obesity in mice with long-term high-fat diet by regulating gut microbiota and metabolites

Background Obesity is closely linked to gut microbiota dysbiosis and metabolic disorders. Portulaca oleracea polysaccharide (POP) has potential metabolic benefits, but its effects and mechanisms against obesity remain unclear. This study aimed to investigate the ameliorative effects of POP on high-fat diet (HFD)-induced obesity in mice. Methods C57BL/6J mice were fed an HFD supplemented with 3.2% POP for 17 weeks. Obesity-related parameters, gut microbiota, and serum metabolomics were analyzed. Results POP significantly reduced obesity, improved lipid profiles and glucose homeostasis, increased gut microbiota diversity, and normalized the Firmicutes/Bacteroidetes ratio. It modulated several key gut microbiota genera and altered metabolites including LacCer (d18:1/12:0) and N-(4,7-Dihydroxy-8-Methyl-2-Oxo-2H-Chromen-3-Yl)-2,2-Dimethylchromane-6-Carboxamide (NDC), which strongly correlated with obesity-related indices. Conclusion POP may improve HFD-induced obesity by regulating gut microbiota and host metabolism. These results provide a theoretical basis for POP as a potential functional component against obesity.