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Laungani, D.

Publications and source records attributed to Laungani, D..

2 recordsLinked to original sources

Gut Microbe-Derived N-Acyl Serinol Lipids Shape Host Postprandial Metabolic Homeostasis

Although strong evidence links the gut microbiome to metabolic disease, the mechanisms linking microbiota to hormonal and metabolic responses to food are not well understood. After a meal, gut bacteria produce a wide array of small molecule, protein, and lipid metabolites originating from bacterial sources. Annotating physiological function to select gut microbe-derived metabolites is critical to understanding diet-microbe-host interactions, and to developing microbiome-inspired therapies to improve human health. Here, we have investigated the role of a poorly annotated class of gut microbiome-derived lipids called N-acyl amides in postprandial metabolic physiology. Here we show both bacterial overproduction and provision of exogenous N-acyl amides reorganize host hormone-driven metabolic transition after a meal. Moreover, N-acyl amides exert broad effects on the meal- and circadian-related reorganization of gene expression, metabolic hormones, and gut microbiome composition. Collectively, these results demonstrate that microbiota-derived N-acyl amides play a physiologic role in postprandial metabolic homeostasis in the host.

physiology↗

Gut Microbe-Derived Trimethylamine Shapes Circadian Rhythms Through the Host Receptor TAAR5

Elevated levels of the gut microbe-derived metabolite trimethylamine N-oxide (TMAO) are associated with cardiometabolic disease risk. However, the mechanism(s) linking TMAO production to human disease are incompletely understood. Initiation of the metaorganismal TMAO pathway begins when dietary choline and related metabolites are converted to trimethylamine (TMA) by gut bacteria. Gut microbe-derived TMA can then be further oxidized by host flavin-containing monooxygenases to generate TMAO. Previously, we showed that drugs lowering both TMA and TMAO protect mice against obesity via rewiring of host circadian rhythms. Although most mechanistic studies in the literature have focused on the metabolic end product TMAO, here we have instead tested whether the primary metabolite TMA alters host metabolic homeostasis and circadian rhythms via trace amine-associated receptor 5 (TAAR5). Remarkably, mice lacking the host TMA receptor (Taar5-/-) have altered circadian rhythms in gene expression, metabolic hormones, gut microbiome composition, and diverse behaviors. Also, mice genetically lacking bacterial TMA production or host TMA oxidation have altered circadian rhythms. These results provide new insights into diet-microbe-host interactions relevant to cardiometabolic disease, and implicate gut bacterial production of TMA and the host receptor that senses TMA (TAAR5) in the physiologic regulation of circadian rhythms in mice. HIGHLIGHTSO_LIMice lacking the host TMA receptor (Taar5-/-) have altered circadian rhythms. C_LIO_LITaar5-/- mice have altered innate behaviors in a time of day dependent manner. C_LIO_LIThe normal circadian oscillations in the gut microbiome are dysregulated in Taar5-/- mice. C_LIO_LIGenetic deletion of bacterial TMA production or host TMA oxidation shapes circadian rhythms. C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=137 HEIGHT=200 SRC="FIGDIR/small/647082v2_ufig1.gif" ALT="Figure 1"> View larger version (45K): org.highwire.dtl.DTLVardef@1608forg.highwire.dtl.DTLVardef@6a809aorg.highwire.dtl.DTLVardef@2131f7org.highwire.dtl.DTLVardef@1575559_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗