The Effect of Probiotics on the Improvement of Body Weight and Fat

This study aimed to investigate the effects of Lactiplantibacillus plantarum (L. plantarum) ST-Ⅲ and oats supplementation on high-fat diet (HFD)–induced obesity in rats, focusing on changes in body weight, organ/fat tissue weights, inflammatory markers, serum parameters, and gut microbiota composition. Male Sprague–Dawley rats (n ≥ 6/group) were fed a normal diet (ND) or HFD for 9 weeks to establish obesity. Then, HFD-fed rats were divided into four groups: HFD + ST-Ⅲ, ND + ST-Ⅲ, HFD + Oats, and ND + Oats, receiving daily oral gavage of ST-III (1.5 × 10⁹ CFU/rat) or oats for another 9 weeks. Body weight, serum lipids, cytokines (e.g., IL-6, PYY, and MCP-1), liver histopathology, and gut microbiota were analyzed. Notably, weight loss is primarily influenced by diet, and better results can be achieved by controlling diet in combination with new edible L. plantarum ST-Ⅲ in promoting weight loss. L. plantarum ST-Ⅲ reduced the levels of the factors CORT and MCP-1, thereby potentially promoting weight loss. The ST-Ⅲ group showed earlier weight reduction (significant at Week 2) than the oats group (at Week 6). Gut microbiota analysis revealed differential abundances of Lactiplantibacillus, Blautia, and Prevotella between intervention groups. No significant differences in liver or organ weights were observed. L. plantarum ST-Ⅲ and oats attenuated HFD-induced obesity by modulating metabolic parameters, inflammation, and gut microbiota. ST-Ⅲ exhibited quicker anti-obesity effects, while oats enhanced probiotic growth. Dietary structure improvement remains critical for weight management. Further studies should address stress-related experimental limitations and explore clinical applications.