Abstract
Artificial sweeteners may alter taste sensitivity and feeding behavior, but their effects compared to natural sugars and the role of the gut microbiome in modulating these responses remain unclear. This study compares taste sensitivity and consumption responses to erythritol (Truvia), sucralose (Splenda), and sucrose in flies with a gut microbiome (conventional) and without a microbiome (axenic). Taste sensitivity was assessed using the proboscis extension response (PER) assay, while the capillary feeder (CAFE) assay was used to measure consumption. PER results revealed that sucrose elicited a significantly stronger taste response than Splenda or Truvia, with response rates increasing at higher concentrations. CAFE assays indicated fly aversion to Truvia, and axenic flies consuming significantly more Truvia compared to conventional flies, suggesting a significant microbiome effect. In the Splenda trials, axenic flies consumed significantly more yeast than those in the sucrose treatment, suggesting a potential compensatory feeding response due to the lack of calories in artificial sweeteners.