Gut Commensal Phocaeicola vulgatus AF107-22 Alleviates Obesity-Induced Metabolic Syndrome via Promoting Gut Microbiota-Derived Spermidine Synthesis

Obesity-induced metabolic syndrome (MetS) is a prevalent metabolic disorder, and therapeutic strategies targeting the gut microbiota hold considerable promise. Phocaeicola vulgatus (P. vulgatus) is a gut commensal bacterium that plays an important role in modulating the composition and metabolism of gut microbiota. This study demonstrated that the abundance of P. vulgatus is significantly negatively correlated to obesity-induced MetS and complications in human metagenomic data. Oral gavage of P. vulgatus significantly ameliorated high-fat-diet (HFD)-induced MetS symptoms in mice, reducing body weight, systemic inflammation, and hepatic steatosis. Furthermore, multiomics analyses indicated that P. vulgatus treatment significantly enhanced the production of gut microbiota-derived spermidine and spermine. Subsequently, population-based analysis confirmed a strong negative correlation between plasma spermidine levels and MetS progression, supporting that such parameters may serve as potential biomarkers for MetS. This study reveals a potential mechanism, bridging commensal probiotic and spermidine metabolism, with implications for treating obesity-induced MetS.