Butyrate, a short-chain fatty acid produced by gut bacteria, improves insulin sensitivity and increases energy expenditure in mice fed a high-fat diet. In this study, sodium butyrate was administered at 5% of the high-fat diet to C57BL/6J mice, preventing the development of insulin resistance and obesity. The treated mice maintained normal fasting blood glucose, insulin levels, and insulin tolerance, while body fat remained at 10% without reduced food intake. Adaptive thermogenesis and fatty acid oxidation were enhanced, with increased mitochondrial function and biogenesis in skeletal muscle and brown fat. Type I fibers were enriched in skeletal muscle, and PGC-1α expression was elevated at both mRNA and protein levels. AMPK and p38 activities were also increased. In obese mice, butyrate supplementation improved insulin sensitivity and reduced adiposity. The study suggests that dietary butyrate can prevent and treat diet-induced insulin resistance in mice. The mechanism involves promoting energy expenditure and inducing mitochondrial function. Butyrate activates PGC-1α, which enhances mitochondrial biogenesis and energy metabolism. AMPK activation and histone deacetylase inhibition may contribute to PGC-1α regulation. Butyrate and its derivatives may have potential in preventing and treating metabolic syndrome in humans. The findings indicate that butyrate's effects are similar to those of resveratrol, with a molecular mechanism involving PGC-1α activation and mitochondrial function induction.Butyrate, a short-chain fatty acid produced by gut bacteria, improves insulin sensitivity and increases energy expenditure in mice fed a high-fat diet. In this study, sodium butyrate was administered at 5% of the high-fat diet to C57BL/6J mice, preventing the development of insulin resistance and obesity. The treated mice maintained normal fasting blood glucose, insulin levels, and insulin tolerance, while body fat remained at 10% without reduced food intake. Adaptive thermogenesis and fatty acid oxidation were enhanced, with increased mitochondrial function and biogenesis in skeletal muscle and brown fat. Type I fibers were enriched in skeletal muscle, and PGC-1α expression was elevated at both mRNA and protein levels. AMPK and p38 activities were also increased. In obese mice, butyrate supplementation improved insulin sensitivity and reduced adiposity. The study suggests that dietary butyrate can prevent and treat diet-induced insulin resistance in mice. The mechanism involves promoting energy expenditure and inducing mitochondrial function. Butyrate activates PGC-1α, which enhances mitochondrial biogenesis and energy metabolism. AMPK activation and histone deacetylase inhibition may contribute to PGC-1α regulation. Butyrate and its derivatives may have potential in preventing and treating metabolic syndrome in humans. The findings indicate that butyrate's effects are similar to those of resveratrol, with a molecular mechanism involving PGC-1α activation and mitochondrial function induction.