Discovery and characterization of gut microbiota decarboxylases that can produce the neurotransmitter tryptamine. Author Brianna Williams, Andrew Van Benschoten, Peter Cimermancic, Mohamed Donia, Michael Zimmermann, Mao Taketani, Atsushi Ishihara, Purna Kashyap, James Fraser, Michael Fischbach Publication Year 2014 Type Journal Article Abstract Several recent studies describe the influence of the gut microbiota on host brain and behavior. However, the mechanisms responsible for microbiota-nervous system interactions are largely unknown. Using a combination of genetics, biochemistry, and crystallography, we identify and characterize two phylogenetically distinct enzymes found in the human microbiome that decarboxylate tryptophan to form the β-arylamine neurotransmitter tryptamine. Although this enzymatic activity is exceedingly rare among bacteria more broadly, analysis of the Human Microbiome Project data demonstrate that at least 10% of the human population harbors at least one bacterium encoding a tryptophan decarboxylase in their gut community. Our results uncover a previously unrecognized enzymatic activity that can give rise to host-modulatory compounds and suggests a potential direct mechanism by which gut microbiota can influence host physiology, including behavior. Keywords Molecular Sequence Data, Humans, Bacteria, Models, Molecular, Crystallography, X-Ray, Protein Conformation, Amino Acid Sequence, Gastrointestinal Tract, Microbiota, Tryptophan, Metagenome, Biotransformation, Carboxy-Lyases, Neurotransmitter Agents, Phylogeny, Sequence Homology, Tryptamines Journal Cell Host Microbe Volume 16 Issue 4 Pages 495-503 Date Published 2014 Oct 08 ISSN Number 1934-6069 DOI 10.1016/j.chom.2014.09.001 Alternate Journal Cell Host Microbe PMCID PMC4260654 PMID 25263219 PubMedPubMed CentralGoogle ScholarBibTeXEndNote X3 XML