The Cephalic Phase Responses of Celiac Artery Blood Flow and Gastric Motility to Oral Sweet Taste

Abstract

In humans little is known as to whether oral sensation of sweetness elicits any changes of splanchnic blood flow and gastrointestinal motility. The aim of this study, therefore, was to examine whether any effect of different oral sweet stimuli on celiac artery blood flow (CABF, which predominantly perfuses the stomach) and gastric motility occur. The oral stimulation was performed as follows: Subjects sipped a taste solution without swallowing. The fluid was then spat out, and subjects remained for post‐stimulation recording. During the protocol, CABF and gastric motility were continuously measured using pulsed Doppler ultrasonography and electrogastrography (EGG), respectively. In the experiment 1, 18% glucose (Glu), 18% maltodextrin (Mal) and mineral water (MW) were used for orosensory stimulation. Whereas all solutions had no effect on gastric motility, the stimulus by Glu (i.e. sweet taste solution) increased CABF acutely (p<0.05), but those by Mal and MW (i.e. non‐sweet taste solutions) did not. Accordingly, as the experiment 2, different concentrations of glucose (0, 4, 16, and 48%) were adopted to examine the dose‐response relationship of oral sensation of sweetness on CABF. While three glucose solutions, excepting 0%, increased the CABF (16, 21, and 23% from baseline, respectively; p<0.05), there were no significant differences among them. These results suggest that oral sensation of sweetness acutely increases CABF without augmentation of gastric motility, while it is not certain that the CABF is increased proportionally with the sweet taste intensity.