Mapping Lipid C═C Isomer Profiles of Human Gut Bacteria through a Novel Structural Lipidomics Workflow Assisted by Chemical Epoxidation
Journal
Analytical Chemistry
Journal Volume
96
Journal Issue
44
Start Page
17526
End Page
17536
ISSN
0003-2700
1520-6882
Date Issued
2024-10-22
Author(s)
Abstract
The unsaturated lipids produced by human gut bacteria have an extraordinary range of structural diversity, largely because of the isomerism of the carbon-carbon double bond (C═C) in terms of its position and stereochemistry. Characterizing distinct C═C configurations poses a considerable challenge in research, primarily owing to limitations in current bioanalytical methodologies. This study developed a novel structural lipidomics workflow by combining MELDI (meta-chloroperoxybenzoic acid epoxidation for lipid double-bond identification) with liquid chromatography-tandem mass spectrometry for C═C characterization. We utilized this workflow to quantitatively assess more than 50 C═C positional and cis/trans isomers of fatty acids and phospholipids from selected human gut bacteria. Strain-specific isomer profiles revealed unexpectedly high productivity of trans-10-octadecenoic acid by Enterococcus faecalis, Bifidobacterium longum, and Lactobacillus acidophilus among numerous trans-fatty acid isomers produced by gut bacteria. Isotope-tracking experiments suggested that gut bacteria produce trans-10-octadecenoic acid through the isomeric biotransformation of oleic acid in vitro and that such isomeric biotransformation of dietary oleic acid is dependent on the presence of gut bacteria in vivo. © 2024 The Authors. Published by American Chemical Society.
Publisher
American Chemical Society (ACS)
Type
journal article