A “Population-based Approach” To Study The Impact Of PROP Perception On Food Liking In Populations Along The Silk Road

Responsiveness to certain bitter tasting compounds, such us PROP (6-n-propylthiouracil), is a variable trait both within and between human populations. Genetic variations in the TAS2R38 taste gene accounts for a major portion of phenotypic variation in PROP taste sensitivity. PROP-related differences have been also shown to influence food preferences and dietary behaviour, but this relation is extremely complex and findings are not always uniform. In this study we first examined the link between taste responses to PROP and self-reported food preferences in six different populations of the Caucasus and Central Asia, located along the ancient Silk Road. In addition, we performed a candidate gene study aimed to identify if other genes of the TAS2R family contribute to the PROP phenotype, in association with TAS2R38. We found a strong relationship between PROP tasting and food preferences (Mantel test 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 preferences and the matrix of genetic distance based on TAS2R38. Preliminary results of candidate gene analysis allow us to identify other TAS2R genes that could cooperate with TAS2R38 in the modulation of PROP perception and as consequence also food liking. Our results suggest that PROP status is probably a marker for general taste sensitivity and as such is a major driver of food preferences. The “population-based approach” proved to be a good method to clarify the controversial relation between PROP perception and food liking and could possibly be applied to other traits as well. In addition, our work represents a starting point to study the involvement of multiple genes in PROP perception and food liking.