Degraded sweet corn cob polysaccharides modulate T2DM-induced abnormalities in hepatic lipid metabolism via the bile acid-related FXR-SHP and FXR-FGF15-FGFR4 pathways

Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by dysregulation of glucose and lipid metabolism. This study aimed to elucidate the mechanism through which a degraded sweet corn cob polysaccharide (UE-DSCCP-A) mitigates T2DM by modulating hepatic lipid metabolism. Biochemical indices pertinent to lipid metabolism were assessed, and liver pathology was examined in T2DM mice following UE-DSCCP-A treatment. Additionally, metabolomics, PCR, and Western blot analyses were employed to investigate the underlying mechanisms involved. These findings indicated that UE-DSCCP-A ameliorated hepatic lipid metabolism disorders, decreased lipid accumulation, and mitigated hepatic fibrosis. Untargeted metabolomics analysis revealed that UE-DSCCP-A modulated pathways associated with steroid biosynthesis and bile acid synthesis and metabolism in T2DM mice. The bile acid assay results demonstrated that UE-DSCCP-A treatment reduced bile acid levels in both the serum and liver but increased fecal bile acid levels in T2DM mice. Furthermore, alterations in bile acid distribution within the liver were observed. UE-DSCCP-A has the capacity to activate the hepatic FXR-SHP pathway as well as the gut-liver axis involving FXR-FGF15-FGFR4 signaling. Consequently, UE-DSCCP-A is capable of modulating critical target genes and proteins associated with bile acid synthesis and metabolism, regulating steroid biosynthesis, and influencing bile acid synthesis and transport within the liver. Additionally, it has beneficial effects on lipid metabolism disorders in individuals with T2DM. Thus, UE-DSCCP-A represents a promising candidate for functional foods with inherent hypoglycemic properties.