Peri-threshold Trigeminal Stimulation with Capsaicin Increases Taste Sensitivity in Humans

Abstract Introduction Taste perception is affected by trigeminal stimuli, i.e., capsaicin. This has been studied at suprathreshold concentrations. However, little known about taste threshold level in the presence of low concentration The aim study was to explore whether sensitivity for sweet, sour, salt, bitter, and umami modulated capsaicin peri-threshold range. Methods Fifty-seven adults (age range 19–85 years; 32 women) with functional gustation participated study. Based on their phenylthiocarbamide (PTC), group stratified into non-tasters ( n = 20) tasters 37). Threshold sweet (sucrose), sour (citric acid), salty (sodium chloride), bitter (quinine-hydrochloride), (sodium-glutamate) tastes estimated using a single-staircase paradigm (3-alternative forced choice; volume per trial 0.1 ml) or without 0.9-µM added. had determined pilot studies be oral thresholds. Results addition produced lower thresholds salty, but not umami. In contrast, neither PTC taster status nor sex these results. Conclusion current results indicate that increases gustatory sensitivity. Implications findings provide evidence supporting different effects level. It implications boosting flavor enjoyment