Multi-omics insights into inulin mediated enhancement of the large yellow croaker (Larimichthys crocea) growth during the summer season heat stress

Elevated mortality rates and growth suppression of large yellow croaker ( Larimichthys crocea ) under prolonged high summer temperatures present significant challenges for sustainable aquaculture. In response to these thermal stress pressures, this study investigates the effects of dietary inulin supplementation on the resilience and growth performance of juvenile large yellow croaker. Over a two-month period (July 14 to September 14), fish were acclimated and assigned to five diet groups containing 0 %, 0.1 %, 0.2 %, 0.4 %, and 0.8 % inulin. Using a multi-omics approach (transcriptomic, metabolomic, and microbiomic changes) in liver and gut tissues, we assessed the effect of inulin in Larimichthys crocea . Results demonstrated that an optimal inulin level (0.4 %) significantly improved growth performance. Transcriptomic data revealed upregulation of genes involved in energy metabolism pathways such as glycolysis and fatty acid biosynthesis, alongside downregulation of immune and stress-related genes. Metabolomic profiles showed increased metabolites related to energy production and lipid metabolism. Gut microbiome analysis indicated a reduction in overall diversity but enrichment of beneficial bacteria , including Lactobacillus , which correlated with higher levels of health-promoting short-chain fatty acids and amino acids. Integrated analyses highlighted strong associations between key microbial taxa and metabolic pathways supporting nutrient absorption and vitamin synthesis. These findings suggest that dietary inulin enhances thermal stress tolerance by modulating metabolism and gut microbiota, offering a promising nutritional strategy to improve large yellow croaker aquaculture under change-induced heat stress. • Inulin raised growth rate and weight in L. crocea at optimal 0.5 % diet concentration. • Transcriptome analysis showed genes boosting immune response and growth hormone. • Liver metabolomics indicated increased lipid metabolism and material transport. • Inulin increased beneficial intestinal bacteria like Firmicutes . • Inulin promotes bile secretion in large yellow croaker.