Bitter Receptors Control Glucose Absorption in the Gut by Modifying the G-protein Coupled Receptor Signaling Cascade

Taste perception is an important aspect of food intake and may also influence carbohydrate absorption during digestion due to the localization of taste receptors throughout the gastrointestinal tract. Whereas bitterness has long been assumed an evolutionary signal for toxicity, current research suggests that activation of bitter Type 2 Receptors (T2Rs) influences glucose absorption and utilization in human and animal models. No mechanism has yet explained these effects, therefore this project investigated key points in G-protein coupled receptor (GPCR) signaling, downstream of T2Rs. In mouse intestinal STC-1 cells, bitter compounds modulated the GPCR signaling cascade, downstream hormonal signals of carbohydrate consumption, and cell membrane expression of various bitter and glucose receptors. In C57Bl/6J mice, concurrent administration of bitter compounds and glucose load resulted in decreased absorption of glucose in the GI tract, with a subsequent rise in GLP-1 and CCK levels. Together, these data sugg...