/ Single-Nucleotide Polymorphisms Affect Sweet Taste Receptor Activation by Sweeteners: The SWEET Project.

BACKGROUND/OBJECTIVES: Studies have hypothesised that single-nucleotide polymorphisms (SNPs) in the and genes may alter sweet compound detection and eating habits, thereby increasing the risk of obesity. This in vitro study aims to measure the impact of human / polymorphisms, some of which are thought to be involved in obesity, on the response of the sweet taste receptor to various sweeteners. It also aims to identify new SNPs in an obese population associated with a decrease in or loss of function.

METHODS

First, the effects of 12 human -SNPs and 16 human -SNPs, previously identified in the literature, on the response of the sweet taste receptor stimulated by 12 sweeteners were investigated using functional cellular assays. Second, a total of 162 blood samples were collected from an obese population (BMI between 25 and 35 kg/m) involved in the SWEET project. The TaqMan method for SNP genotyping was carried out using DNA extracted from blood samples to identify new SNPs and predict possible/probable TAS1R2/TAS1R3 loss of function.

RESULTS

Although certain human / SNPs showed reduced receptor response, they were not associated with particular phenotypes. Seven SNPs were predicted to severely impair the human TAS1R2/TAS1R3 response to sweeteners.

CONCLUSIONS

Although some - and -SNPs have previously been associated with obesity, our cellular results do not confirm this association and reinforce the hypothesis, put forward by other researchers, that sweet taste perception and sugar consumption are governed by factors other than the and genes.