Microbiota-induced alteration of kynurenine metabolism in macrophages drives formation of creeping fat in Crohn's disease.

Hyperplasia of mesenteric tissues in Crohn's disease, called creeping fat (CrF), is associated with surgical recurrence. Although microbiota translocation and colonization have been found in CrF, convincing mouse phenotypes and the underlying mechanisms of CrF formation remain unclear. Utilizing single-nucleus RNA (snRNA) sequencing of CrF and different mouse models, we demonstrate that the commensal Achromobacter pulmonis induces mesenteric adipogenesis through macrophage alteration.