Integrated Multi-Omics Analysis Reveals the Role of Resveratrol in Regulating the Intestinal Function of Megalobrama amblycephala via m6A Methylation

Resveratrol (RES), a natural polyphenol with lipid metabolism-regulating properties, also demonstrates remarkable efficacy in strengthening intestinal barrier integrity. In order to elucidate the mechanism by which RES ameliorates intestinal damage and lipid metabolism disturbances in <i>Megalobrama amblycephala</i> under a high-fat (HF) diet, a conventional diet (CON), an HF diet (HF), or an HF diet supplemented with 0.6, 3, or 6 g/kg RES (HF + 0.06%, 0.3%, or 0.6% RES) was fed to fish. After 8 weeks, RES supplementation in the HF diet significantly improved the growth performance and alleviated hepatic lipid deposition. Microbiota profiling revealed RES improved intestinal barrier function by reducing α-diversity, Actinobacteria and <i>Bosea</i> abundances, and enriching Firmicutes abundance. RES also maintained the integrity of the intestinal physical barrier and inhibited the inflammatory response. MeRIP-seq analysis indicated that RES modulated intestinal mRNA m⁶A methylation by upregulating methyltransferase-like 3 (<i>mettl3</i>) and downregulating fat mass and obesity-associated gene (<i>fto</i>) and Alk B homolog 5 (<i>alkbh5</i>). Combined RNA-seq and MeRIP-seq data revealed that RES alleviated endoplasmic reticulum stress (ERS) by upregulating the m⁶A methylation and gene level of heat shock protein 70 (<i>hsp70</i>). Correlation analyses identified significant associations between intestinal microbiota composition and ERS, tight junction, and inflammation. In summary, RES ameliorates lipid dysregulation via a synergistic mechanism involving intestinal microbiota, m⁶A modification, ERS, barrier function, and inflammatory response.