The functional abundance of glucose and fatty acid metabolic pathways was assessed using the phylogenetic investigation of communities by the reconstruction of unobserved states 2 (PICRUSt2), which showed that gut microbial changes in the HFD group affected fatty acid biosynthesis, fatty acid elongation, fatty acid metabolism, the PPAR signaling pathway, the TCA cycle, glycolysis/gluconeogenesis, insulin resistance, pyruvate metabolism, and NAFLD progression (Figure 2E and Table S1). This evidence concerns the gene INS and metabolic dysfunction-associated steatotic liver disease.