Microbiota–modulated CART+ enteric neurons autonomously regulate blood glucose

Microbial density and diversity increase in distal intestinal segments, affecting tissue physiology, metabolism, and function of both the immune and nervous systems. We characterized the influence of the microbiota on murine intrinsic enteric-associated neurons (iEAN). We found that iEAN are functionally adapted to the intestinal segment they occupy, with a stronger microbiota influence on ileal and colonic neurons. Chemogenetic characterization of microbiota-influenced iEAN identified a subset of viscerofugal CART+ neurons, enriched in the ileum and colon, able to modulate feeding and glucose metabolism. Retro- and anterograde tracing revealed that CART+ viscerofugal neurons send axons to the prevertebral ganglia and are poly-synaptically connected to the liver and pancreas. Microbiota depletion led to NLRP6 and Caspase 11-dependent loss of CART+ neurons, and impaired liver-mediated gluconeogenesis. Our results demonstrate a region-specific adaptation of enteric neurons and indicate that iEAN subsets are capable of regulating blood glucose levels independently from the central nervous system. Actively translated mRNA profiles from immunoprecipitated ribosome-bound mRNA from the duodenum, ileum, and colon of germ-free or specific pathogen free Snap25:RiboTag mice were prepared by deep sequencing on an Illumina NextSeq.