In the representative gut bacterium Lactobacillus plantarum, we identified genes encoding the enzymes involved in a saturation metabolism of polyunsaturated fatty acids and revealed in detail the metabolic pathway that generates hydroxy fatty acids, oxo fatty acids, conjugated fatty acids, and partially saturated transfatty acids as intermediates. Furthermore, we observed these intermediates, especially hydroxy fatty acids, in host organs. Levels of hydroxy fatty acids were much higher in specific pathogen-free mice than in germ-free mice, indicating that these fatty acids are generated through polyunsaturated fatty acids metabolism of gastrointestinal microorganisms. These findings suggested that lipid metabolism by gastrointestinal microbes affects the health of the host by modifying fatty acid composition.biohydrogenation | hydratase | fatty acid isomerase | conjugated linoleic acid | lipid nutrition

Antibiotics and dietary habits can affect the gut microbial community, thus influencing disease susceptibility. Although the effect of microbiota on the postnatal environment has been well documented, much less is known regarding the impact of gut microbiota at the embryonic stage. Here we show that maternal microbiota shapes the metabolic system of offspring in mice. During pregnancy, short-chain fatty acids produced by the maternal microbiota dictate the differentiation of neural, intestinal, and pancreatic cells through embryonic GPR41 and GPR43. This developmental process helps maintain postnatal energy homeostasis, as evidenced by the fact that offspring from germ-free mothers are highly susceptible to metabolic syndrome, even when reared under conventional conditions. Thus, our findings elaborate on a link between the maternal gut environment and the developmental origin of metabolic syndrome.

Background: Endogenous mediators that control aberrant inflammation are of interest as potential targets of new therapeutics.Results: Here, we identified a novel omega-3 fatty acid-derived anti-inflammatory mediator 17,18-diHEPE, denoted as resolvin E3.Conclusion: Resolvin E3 has a potent inhibitory action on neutrophil chemotaxis both in vitro and in vivo.Significance: The significance of this study is the identification of a novel endogenous lipid mediator with a potent anti-inflammatory property.

Macrophage-derived 18-HEPE protects mice from cardiac remodeling by preventing proinflammatory activation of cardiac fibroblasts and subsequent fibrosis.