Long term exposure to sucralose alters the sense of sweet tastants in an intestinal enteroendocrine cell model

Abstract

Artificial sweeteners can bind to the sweet taste receptors T1R2/T1R3 on the cell membrane of taste receptor cells, including intestinal enteroendocrine cells, and induce an increase in intracellular Ca2+ concentration ([Ca2+]i). Acute adaptation or a reduction in receptor signalling was observed after prolonged exposure to a taste stimulus in an animal model. However, at the cell level, it remains unclear whether the expression level of T1R2/T1R3 will be changed by pre-exposure to sweetener molecules, and whether the corresponding change in [Ca2+]i induced by the altered expression of sweet taste receptors varies. In the present work, western blotting and qPCR analysis showed that the expression level of T1R2/T1R3 in NCI-H716 cells was upregulated by sucralose stimulation. In the sucralose-treated cells, the accumulation of intracellular Ca2+ in the sweetener pre-treated cells was significantly enhanced as compared to that in cells without sweetener pre-treatment, although the sweet response differed between acesulfame K and sucralose with the same sweetness. Collectively, the increased expression of T1Rs in sweetener pre-incubated cells enhanced the sweet taste signal response, which implies that long-term administration of artificial sweeteners in beverages or foods could alter the sensitivity of taste receptor cells to sweetener molecules.