Western-style cafeteria diet is linked to impaired colonic barrier integrity and alterations in mitochondrial respiratory proteins.

AIMS: Western-style hyperpalatable diets are recognized as biologically active exposures that disturb intestinal homeostasis, yet the molecular changes linking obesogenic nutrition to colonic injury remain insufficiently defined. This study investigated how cafeteria-diet exposure reshapes colonic homeostasis by integrating metabolic alterations, proteomic changes, tissue injury, antioxidant defense, and inflammatory signaling. MATERIALS AND METHODS: Male Wistar rats were fed a standard or cafeteria diet for 12 weeks. Colonic responses were assessed by metabolic profiling, label-free quantitative nLC-MS/MS proteomics, functional enrichment and protein-protein interaction analyses, Western blotting, histopathology, immunofluorescence, and immunohistochemistry. KEY FINDINGS: Cafeteria-diet feeding induced metabolic deterioration, with increased body weight, fasting glucose, body mass index, insulin, leptin, and circulating LPS. Colonic MDA and 4-HNE immunoreactivity were increased, whereas SOD was reduced. Proteomic profiling identified 132 exploratory differentially expressed protein candidates, including 54 upregulated and 78 downregulated proteins. Functional enrichment revealed two signatures: upregulated mitochondrial respiration-related pathways and downregulated desmosome-, cell-cell junction-, and glutathione-related processes. Hub proteins included COX7A2, COX6C, COX5B, COX7, MT-CO1, JUP, PKP1, DSG1, and DSG4. Western blot analysis of colon samples confirmed increased MT-CO1 abundance. These alterations were accompanied by lamina propria inflammation, epithelial necrosis, crypt dilatation, submucosal edema, goblet cell depletion, reduced occludin, claudin-1 and ZO-1, decreased total NRF2 and HO-1, and increased NF-κB p65 expression. Exploratory correlations linked tight junction markers with antioxidant, inflammatory, oxidative, and metabolic parameters. SIGNIFICANCE: These findings define an integrated metabolic, mitochondrial protein, redox, inflammatory, and barrier-related signature associated with cafeteria-diet exposure and identify candidate indicators for future studies of diet-induced colonic injury.