Highlights • Gpr17 is expressed in GLP-1-producing EECs in human and rodent gut epithelium • Loss of gut Gpr17 increases insulin release and improves glucose tolerance in mice • Gpr17 deficiency increases GLP-1 secretion in mice and intestinal organoids • Gpr17-Gαi/βγ signaling regulates GLP-1 secretion by inhibiting cAMP and VDCCs Summary G protein-coupled receptors (GPCRs) in intestinal enteroendocrine cells (EECs) respond to nutritional, neural, and microbial cues and modulate the release...