Enteroendocrine cells (EECs) are a rare subset of gastrointestinal epithelial cells that regulate physiological processes including intestinal motility and secretion, glycemia, and appetite. They represent a diverse cellular population, collectively producing more than twenty different hormones. Gut hormone secretion after a meal is dominated by EECs from the small intestine, whereas the physiological role of the large number of EECs in the large intestine is less clear. Subgroups of EECs like the L, K, and enterochromaffin (Ecm) cells seem to overlap in their gene expression profiles.
Billing, Larraufie et al. studied EECs of the large intestine using single cell RNA-sequencing. They identified different subpopulations of L-cells and Ecm-cells and showed that these likely represent cellular gradients mapping along the proximal-distal and crypt-surface gut axes. Selective stimulation of distal L-cells using Angiotensin-II resulted in significant elevation of plasma glucacon-like peptide-1 levels, suggesting that these cells can contribute to circulating gut hormone concentrations despite their distal location.