Metabolomic Insights into Energy Utilization Strategies of Asiatic Toads (Bufo gargarizans) During Hibernation

Hibernation is a crucial adaptive strategy for amphibians, facilitating survival in harsh environmental conditions by lowering metabolic rates and reducing energy use. This study employed GC-MS and LC-MS metabolomics to systematically analyze the serum metabolome of Bufo gargarizans during hibernation, aiming to uncover its metabolic adaptation mechanisms. A total of 136 differentially expressed metabolites (DEMs) were identified, of which 115 were downregulated and 21 upregulated, mainly involved in amino acid, carbohydrate, and lipid metabolism. KEGG pathway analysis showed that most metabolic pathways were inhibited in the hibernating group, underscoring a significant reduction in overall metabolic activity. Notably, while amino acid and carbohydrate metabolism were significantly reduced, lipid metabolism exhibited a distinctive adaptive response. Enhanced β-oxidation of fatty acids, including palmitoleic acid, arachidonic acid, and sodium caprylate, suggests a metabolic shift toward lipid-based energy utilization. The reduction in key metabolites like fumaric acid and succinic acid in the TCA cycle further supports the hypothesis of reduced energy requirements. These results enhance our current understanding of amphibian hibernation metabolisms and provide a targeted approach for future mechanistic investigations.