Inflammation associated ethanolamine facilitates infection by Crohn’s disease-linked adherent-invasive Escherichia coli

The predominance of specific bacteria within the Crohn’s disease intestine remains poorly understood with little evidence uncovered to support a selective pressure underlying their presence. Intestinal ethanolamine is readily accessible during periods of intestinal inflammation, and enables pathogens to outcompete the host microbiota under such circumstances. Here we show that the intestinal short chain fatty acid propionic acid stimulates increased ethanolamine degradation by one such Crohn’s disease associated pathogen, adherent-invasive Escherichia coli (AIEC). This degradation occurs within bacterial microcompartments that are subsequently excreted in outer membrane vesicles. Additionally ethanolamine, added extracellularly at concentrations comparable to those in the human intestine, is accessible to intracellular AIEC and stimulates significant increases in growth within macrophages. Finally, expression of the operon for ethanolamine degradation (eut) is increased in children with active Crohn’s disease compared to healthy controls. After clinical remission was seen with exclusive enteral nutrition treatment, Crohn’s disease patient’s exhibit significantly reduced eutexpression. Our data indicates a role for ethanolamine metabolism in facilitating AIEC colonization of the Crohn’s disease intestine and warrants further study of its potential use as an indicator of inflammatory status in Crohn’s disease.