The gut microbiota regulates serotonin (5-HT) levels in the intestinal epithelium and lumen. However, it is not known whether 5-HT has a functional role in gut microbiota bacteria. We demonstrate here that elevation of 5-HT levels in the intestinal lumen by oral supplementation or genetic deficiency of the host 5-HT transporter (SERT) increases the relative abundance of spore-forming members of the gut microbiota (which promote 5-HT biosynthesis). In this microbial community is Turicibacter sanguinis, an intestinal bacterium that expresses a NSS protein with sequence and structural homology to the mammalian SERT. This bacterium imports 5-HT through a mechanism inhibited by the SSRI fluoxetine. Host association with TS alters intestinal expression of multiple gene pathways including those important for lipid and steroid metabolism with reductions in host systemic triglyceride levels and inguinal adipocyte size.
Conclusions: Gut bacteria report that they collaborate bidirectionally with the serotoninergic system.
Year: 2019
Nationality: USA
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