Gut microbiota-driven remodeling of fresh and oxidized edible oils revealed by integrated GC-MS and UPLC-HRMS/MS...

Thermal processing and storage of edible oils promote lipid oxidation, generating compounds that may affect nutritional quality and consumer safety. After ingestion, these compounds are further transformed by gut microbiota, altering their chemical fate and biological impact. The current study applied an integrated gas chromatography-mass spectrometry (GC-MS) and ultra-high-performance liquid chromatography-high-resolution mass spectrometry-tandem mass spectrometry (UPLC-HRMS/MS) workflow coupled with feature-based molecular networking (FBMN) and chemometric analysis to simultaneously track primary and secondary metabolites formed during oil oxidation and subsequent gut microbial metabolism in corn, sesame, and sunflower oils. Metabolite profiling enabled the annotation of 89 primary metabolites by GC-MS and 55 secondary metabolites by UPLC-HRMS/MS-FBMN. Gut microbiota incubation markedly reduced several oxidation-related compounds, including 2,4-decadienal (0.05-0.11%), 2,4-nonadienal (0.01-0.25%), N-nitrosodiethanolamine (0.03-0.05%), 3,5-diethyl-2-methylpyrazine (0.02-0.24%), oxalic acid (1.2-1.8%), and diethylene glycol (0.2-0.4%), compared with uninoculated controls. In contrast, microbial incubation increased phenol (39-46%) and indole (18.2-22.6%), indicating active microbial metabolism of aromatic amino acids. These findings demonstrate how oxidation-derived oil metabolites are dynamically reshaped by human gut microbiota using a unified multi-platform metabolomics strategy, providing insight into the post-ingestion chemical fate of thermally processed edible oils.