Characteristics of Gracilariopsis lemaneiformis hydrocolloids and their effects on intestine PPAR signaling and liver lipid metabolism in Oreochromis niloticus: A multiomics analysis

This study evaluated the effects of Gracilariopsis lemaneiformis hydrocolloids on Nile tilapia (Oreochromis niloticus) using an advanced multiomics approach (transcriptome and proteome) linked with genomic isoform structure to elucidate the biofunctions of G. lemaneiformis hydrocolloids. The results showed that G. lemaneiformis hydrocolloids did not affect growth, as indicated by the nonsignificant differences in growth and blood biochemical indicators. Regarding the response, both intestine and liver tissues were assessed. These findings indicate that 20 % G. lemaneiformis hydrocolloids enhanced cytokine expression, which may contribute to a biological function in the intestine and liver of O. niloticus. Genome and proteome profiles indicated that G. lemaneiformis hydrocolloids upregulated the intestine and liver peroxisome proliferator-activated receptor (PPAR) signaling pathway, nucleocytoplasmic transport, steroid biosynthesis, and histidine metabolism. In contrast, co-factor biosynthesis, nucleocytoplasmic transport, tryptophan metabolism, arginine and proline metabolism, arginine biosynthesis, and ribosome activity were downregulated. These findings indicate that G. lemaneiformis hydrocolloids significantly affect liver lipid and carbohydrate metabolism. Proteomics analysis revealed that G. lemaneiformis hydrocolloids upregulated the PPAR signaling pathway, playing a crucial role in lipid metabolism. In summary, 20 % G. lemaneiformis hydrocolloids are primarily involved in modulating the intestine and liver PPAR signaling pathway to regulate lipid metabolism.