Modulation of the Bitter Taste to Reduce Calorie Intake.

Abstract

If food or materials enter the oral cavity, molecules contact taste receptors in the oral cavity. The bitter taste is mediated G protein-coupled receptors (GPCR) signaling pathway located in taste bud cells.1 Taste receptors are divided into 2 families: type 1 (T1R) and type 2 (T2R). T1R comprises 3 different subunits: T1R1, T1R2, and T1R3. T2R is bound to bitter molecules, whereas sweetness is detected by T1R and T1R3. Interestingly, these taste receptors were expressed in the gastrointestinal mucosa.2 Recent data support that GPCR family has a role of sensors of gastrointestinal luminal contents, and when GPCR family is stimulated, functional responses are initiated through the activation of G protein signaling cascades. Gα subunits interact with taste receptors. Among Gα subunits, α-gustducin is a taste-specific signaling protein.3,4 Other G protein α-subunits, including α-transducin and Gi, participate in bitter taste transduction, and are associated with phospholipase Cβ2 and a calcium-activated cation channel.5