Taste receptors for bitter substances are not only found on the tongue but also on cells outside the oral cavity. As a new study now shows, extraoral bitter taste receptors could also serve as endogenous sensors for bile acids. This discovery suggests that, in addition to food components, endogenous substances may have influenced the evolution of bitter taste receptors. Furthermore, the study provides new approaches to explore the health effects of food constituents in which extraoral bitter taste receptors are involved.