Polyunsaturated fatty acid saturation by gut lactic acid bacteria affecting host lipid composition

Area of Science:

• Microbiology
• Biochemistry
• Host-Microbe Interactions

Background:

• Polyunsaturated fatty acids (PUFAs) are essential dietary lipids.
• Gut microbiota play a crucial role in host metabolism.
• Limited understanding exists regarding microbial metabolism of PUFAs in the gut.

Purpose of the Study:

• To elucidate the metabolic pathway of PUFA saturation in Lactobacillus plantarum.
• To investigate the generation and presence of PUFA-derived metabolites in host tissues.
• To determine the impact of microbial PUFA metabolism on host health.

Main Methods:

• Genomic and enzymatic analysis of Lactobacillus plantarum.
• Metabolomic profiling of gut microbiota and host tissues.
• Comparative analysis of hydroxy fatty acid levels in germ-free and specific pathogen-free mice.

Main Results:

• Identified genes and detailed the pathway for PUFA saturation in Lactobacillus plantarum.
• Detected hydroxy fatty acids, oxo fatty acids, conjugated fatty acids, and trans-fatty acids as intermediates.
• Observed significantly higher levels of hydroxy fatty acids in specific pathogen-free mice compared to germ-free mice.

Conclusions:

• Gastrointestinal microbes, exemplified by Lactobacillus plantarum, possess pathways for PUFA saturation.
• Microbial-derived fatty acid metabolites, particularly hydroxy fatty acids, are present in host organs.
• Microbial lipid metabolism in the gut influences host health by modifying systemic fatty acid composition.