Metabolic retroconversion of trimethylamine N -oxide and the gut microbiota

  • Lesley Hoyles, Maria L. Jiménez-Pranteda, Julien Chilloux, Francois Brial, Antonis Myridakis, Thomas Aranias, Christophe Magnan, Glenn R. Gibson, Jeremy D. Sanderson, Jeremy K. Nicholson, Dominique Gauguier, Anne L. McCartney, Marc-Emmanuel Dumas
  • December 2017, Cold Spring Harbor Laboratory Press
  • DOI: 10.1101/225581

Dietary TMAO is converted to TMA by gut bacteria and converted back to TMAO in the liver

What is it about?

Trimethylamine N-oxide (TMAO) is a chemical found in human blood and urine. TMAO is produced from methylamines found in food: e.g. choline (eggs), phosphatidylcholine (emulsifiers) and carnitine (meat). When we eat food containing methylamines, our gut bacteria convert these chemicals to trimethylamine (TMA). TMA is taken up into our blood from the intestinal tract and transported to the liver, where TMA is converted to TMAO. We have shown for the first time that TMAO is subject to a process called metabolic retroconversion: that is, dietary TMAO is converted to TMA by gut bacteria then converted back to TMAO by liver enzymes.

Why is it important?

We have demonstrated another example of how gut bacteria and their mammalian hosts interact metabolically: that is, we have demonstrated metabolic retroconversion occurs (dietary TMAO --> gut bacteria TMA --> host TMAO).


Professor Lesley Hoyles
Nottingham Trent University

This was initially a small study that came out of asking 'what happens if you grow lots of different gut bacteria in the presence of TMAO?'. The results we got surprised us, and it became clear we needed to look at the process in a bit more detail, using a mixture of pure culture, mixed culture and mouse work. It's clear from this small study that a lot more work needs to be done to properly understand how TMAO affects gut bacteria growth and metabolism, and how this may affect host health.

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The following have contributed to this page: Professor Lesley Hoyles