Abstract: This study aimed to investigate the anti-obesity effects of Lactobacillus gasseri TF08-1 and its potential mechanisms. An obesity rat model was established by feeding a high-fat diet (HFD) and administered a suspension of L. gasseri TF08-1 (1×10⁵CFU/d) via oral gavage for five weeks. The therapeutic efficacy were systematically evaluated by monitoring body weight, food efficiency ratio, serum biochemical parameters, and histopathological changes in the liver and adipose tissues. Meanwhile, metagenomic sequencing and targeted metabolomic analysis were employed to investigate alterations in the gut microbiota and the short-chain fatty acid (SCFA) profile. The results showed that, compared to the HFD group, TF08-1 intervention significantly suppressed body weight gain (P<0.01), reduced the food efficiency ratio (P<0.001), and alleviated hepatic steatosis and hypertrophy of epididymal adipocytes. It also improved the lipid profile by decreasing low-density lipoprotein cholesterol (LDL-C, P<0.001), triglyceride (TG, P<0.001), total cholesterol (TC, P<0.001) and free fatty acid (FFA, P<0.05). Moreover, TF08-1 intervention significantly mitigated obesity-associated systemic inflammation, reducing the levels of pro-inflammatory factors, including lipopolysaccharide (LPS) (P<0.001), C-reactive protein (CRP) (P<0.001), and tumor necrosis factor-alpha (TNF-α) (P<0.001), while increasing the level of the anti-inflammatory cytokine interleukin-10 (IL-10) (P<0.05). Metagenomic and targeted metabolomic analysis revealed that TF08-1 effectively modulated the HFD-induced structural dysbiosis of the gut microbiota, improved metabolic pathway disturbances related to bile acids, vitamins, and inositol, and restored intestinal SCFA levels. These findings suggest that L. gasseri TF08-1 can markedly improve HFD-induced obesity and related metabolic disorders through effective microbiome modulation, demonstrating its considerable potential as a probiotic candidate for weight management.