Variations at the TAS2R38 gene account for the major portion of differences in PROP (6-n-propylthiouracil) taste perception, which have been shown to influence food preferences and dietary behaviour. We examined the link between PROP taste responses, food preferences and TAS2R genes in six different populations of the Caucasus and Central Asia, located along the Silk Road. We reported, for the first time, genotypic frequencies of the TAS2R38 gene and PROP phenotype distribution in these populations. We found a strong relationship between PROP tasting and food preferences (r=0.67, p-value=0.009) using a “population-based approach”, in which we exploit phenotypic differences between populations comparing a distance matrix based on PROP taste responses and a matrix based on food preferences. No evidence of correlation was found between the distance matrix of food preference and the matrix of genetic distance based on TAS2R38 or the matrix based on the whole genome. Preliminary results of candidate gene analysis allowed us to identify others TAS2R genes that could cooperate with TAS2R38 in the modulation of PROP perception and as consequence food liking.
Besides increasing the knowledge of worldwide TAS2R38 prevalences and bitter taste, our results show that differences in food preferences among populations correlate with PROP status but not with the TAS2R38 gene, suggesting that PROP status is probably a marker for general taste sensitivity and as such is a major driver of food preferences. In addition, our work represent a starting point to study the involvement of multiple genes in bitter perception and food liking.
