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

This study aimed to investigate the effects of <i>Lactiplantibacillus plantarum</i> (<i>L. plantarum</i>) 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 (<i>n</i> ≥ 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 <i>L. plantarum</i> ST-Ⅲ in promoting weight loss. <i>L. plantarum</i> 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 <i>Lactiplantibacillus</i>, <i>Blautia</i>, and <i>Prevotella</i> between intervention groups. No significant differences in liver or organ weights were observed. <i>L. plantarum</i> 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.