VIP-producing enteric neurons interact with innate lymphoid cells to regulate feeding-dependent intestinal epithelial barrier functions

The intestinal mucosa serves as both a conduit for uptake of food-derived nutrients and microbiome-derived metabolites and as a barrier that prevents tissue invasion by microbes and tempers inflammatory responses to the myriad contents of the lumen. How the intestine coordinates physiological and immune responses to food consumption to optimize nutrient uptake while maintaining barrier functions remains unclear. Here, we describe how a gut neuronal signal triggered by food intake is integrated with intestinal antimicrobial and metabolic responses controlled by type 3 innate lymphoid cells (ILC3). Food consumption rapidly activates a population of enteric neurons that express vasoactive intestinal peptide (VIP). Projections of VIP-producing enteric neurons (VIPen) in the lamina propria are in close proximity to clusters of ILC3 that selectively express VIP receptor type 2 (VIPR2 or VPAC2). ILC3 production of IL-22, which is up-regulated by commensal microbes such as segmented filamentous bacteria (SFB), is inhibited upon engagement of VIPR2. As a consequence, there is a reduction in epithelial cell-derived antimicrobial peptide, but enhanced expression of lipid-binding proteins and transporters. During food consumption, activation of VIPen thus enhances growth of epithelial-associated SFB and increases lipid absorption. Our results reveal a feeding- and circadian-regulated dynamic intestinal neuro-immune circuit that promotes a trade-off between innate immune protection and efficiency of nutrient absorption. As intestinal pathogenic microbes disrupt this neuro-immune inhibitory axis, targeting this pathway may enhance intestinal barrier function to prevent invasion by enteropathogens.