Not a “they” but a “we”: The microbiome helps promote our well-being

Stephen W Ragsdale

doi:10.1016/j.jbc.2021.101511

Abstract

Anaerobic microbes in the human gut produce beneficial and harmful compounds, as well as neutral compounds like trimethylamine, which undergoes microbial metabolism or host-catalyzed transformation into proatherogenic trimethylamine-N-oxide. Ellenbogen et al. identified a microbiome-associated demethylase that short-circuits the production of trimethylamine-N-oxide from the metabolite γ-butyrobetaine and instead produces methyltetrahydrofolate, a key intermediate in the microbial production of beneficial small-chain fatty acids. This article highlights an example of how the microbiome is integrally involved in producing metabolites that support our health and in preventing the formation of compounds that promote disease.

Highlights

E. limosum is typically associated with good health and longevity, perhaps partly because of its production of shortchain fatty acids, which are known to serve beneficial functions in human health, including providing fuel for growth of colonocytes (4)
The reason for stating that this system only “partly” contributes to the beneficial effects of E. limosum is that this new finding from the Krzycki laboratory comes on the heels of their discovery of a carnitine demethylase system (MtqA, MtcB, and MtqC) (5) that produces acetate
In the research highlighted here, Ellenbogen et al (3) described a three-protein complex including two of the same proteins (MtqA and MtqC) that associate with MtyB to remove a methyl group from γ-butyrobetaine (Fig. 1) producing methylH4folate, which is subsequently converted to acetic acid

Summary

Introduction

E. limosum is typically associated with good health and longevity, perhaps partly because of its production of shortchain fatty acids, which are known to serve beneficial functions in human health, including providing fuel for growth of colonocytes (4). As suggested by the authors (3), it seems likely that that the butyrobetaine demethylase system is partly responsible for the microbe’s beneficial health effects by lowering the levels of proatherogenic TMA and TMAO in the bloodstream.

Results

Conclusion