Integrated Multi-Omics Analysis Reveals the Physiological and Metabolic Response Mechanisms of Luciobarbus capito Under Cold Stress: Insights from Biochemical Parameters, Gut Microbiota, and Metabolomics

Cold stress is a key environmental constraint in aquaculture, but integrated host responses linking oxidative status, intestinal microbiota, and hepatic metabolism remain insufficiently characterized in Luciobarbus capito. This study aimed to evaluate the biochemical, microbial, and metabolic responses of L. capito to acute low-temperature exposure. Fish were exposed to 12 °C for 96 h, with fish maintained at 22 °C as controls; hepatic antioxidant indices, serum biochemical parameters, intestinal microbiota based on 16S rRNA gene sequencing, and liver metabolomic profiles were analyzed. Cold exposure reduced hepatic total superoxide dismutase (T-SOD) and catalase (CAT) activities and increased malondialdehyde (MDA) content, while serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities increased and acid phosphatase (ACP) activity decreased. The intestinal microbiota showed reduced richness and compositional shifts, including decreased Cetobacterium and increased Pseudomonas. Liver metabolomics identified 172 differential metabolites, with enriched pathways related to glycerophospholipid metabolism, α-linolenic acid metabolism, pantothenate and CoA biosynthesis, and ascorbate and aldarate metabolism. Correlation analysis indicated significant associations between altered bacterial genera and hepatic metabolites. These results suggest that acute cold stress disrupts oxidative balance, intestinal microbial composition, and hepatic metabolism in L. capito, providing an integrated view of associated physiological and metabolic responses to low-temperature stress.