Too much TMAO and GVHD

Abstract

In this issue of Blood, Wu and colleagues report that trimethylamine N-oxide (TMAO), an intestinal microbiome-dependent metabolite, worsens graft-versus-host disease (GVHD). They further found that TMAO induces M1 polarization of bone marrow–derived macrophages via the nucleotide-binding oligomerization domain–like receptor protein 3 (NLRP3). TMAO is produced by hepatic processing of intestinal bacteria–derived trimethylamine (TMA) following metabolism of certain dietary nutrients, including choline, lecithin, l-carnitine, and γ-butyrobetaine.