Two studies in Nature Immunology by Jakob, Sterczyk et al. and Pirzgalska et al. show that neuron-derived vasoactive intestinal peptide (VIP) regulates intestinal epithelial differentiation and orchestrates immune responses. Through its receptor VIPR1, VIP restrains secretory lineage expansion, balances type 1 and type 2 immunity, and establishes a neuro-epithelial circuit preserving gut barrier integrity.
