Synthesis-driven reverse metabolomics reveals 3-hydroxy N-acyl amides as gut microbial molecules.

Area of Science:

• Lipidomics
• Metabolomics
• Biochemistry

Background:

• 3-hydroxy N-acyl amides are bioactive lipids with anti-obesity and glucose-regulating properties.
• These lipids are frequently missed in untargeted metabolomics due to limited spectral reference libraries.

Purpose of the Study:

• To create a comprehensive MS2 spectral resource for 3-hydroxy N-acyl amides.
• To enable the detection and characterization of these lipids in untargeted metabolomics data.
• To investigate the biological relevance and distribution of 3-hydroxy N-acyl amides.

Main Methods:

• Synthesis of 436 diverse 3-hydroxy N-acyl amides.
• Development of an MS2 spectral library.
• Application of a synthesis-driven reverse metabolomics approach.
• Analysis of 54,744 public untargeted metabolomics datasets.
• Validation using retention time and ion mobility measurements.
• Investigation of microbial production and association with diabetes mellitus.

Main Results:

• Identification of 161,626 spectral matches across public datasets.
• Detection of widespread occurrence of 3-hydroxy N-acyl amides in biological samples, including human specimens.
• Discovery of 334 newly reported biological entities within this lipid class.
• Confirmation of presence in human saliva, stool, and skin.
• Evidence supporting microbial production, particularly from gut bacteria.
• Association of altered metabolite abundance with diabetes mellitus.

Conclusions:

• 3-hydroxy N-acyl amides represent a distinct, biologically relevant lipid class.
• The developed MS2 spectral resource significantly enhances their detection in untargeted metabolomics.
• This lipid class is modulated in human metabolic disease and produced by microbes.