Portulaca oleracea Polysaccharide Alleviates Obesity in Mice with Long-Term High-Fat Diet by Regulating Gut Microbiota and Metabolites

This study investigated the ameliorating effects of Portulaca oleracea polysaccharide (POP) on high-fat diet (HFD)-induced obesity in C57BL/6J mice. After a 17-week intervention with free access to an HFD containing 3.2% POP, obesity-related parameters, gut microbiota, and metabolomic changes were analyzed. The results showed that POP significantly reduced obesity severity and lipid levels, and improved glucose homeostasis in mice. This intervention increased gut microbiota diversity, decreased the ratio between Firmicutes and Bacteroidetes (F/B), and significantly increased the relative abundances of Parabacteroides, Acetatifactor, and Incertae_Sedis, while inhibiting the colonization of Anaerotruncus, Enterorhabdus, and Defluviitaleaceae_UCG-011. Metabolomic analysis identified 9r,10s-Epome, LacCer (d18:1/12:0), N-(4,7-Dihydroxy-8-Methyl-2-Oxo-2H-Chromen-3-Yl)-2,2-Dimethylchromane-6-Carboxamide (NDC), and Succinyladenosine as common differential metabolites among the Con, HFD, and POP groups. Notably, LacCer (d18:1/12:0) and NDC were strongly correlated with indicators such as body weight, triglycerides (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C). Our study provides a theoretical basis for elucidating the molecular mechanism by which POP improves obesity.