TAS1R2 sweet taste receptor genetic variation and dietary intake in Korean females

Anti-HIV drugs lopinavir/ritonavir activate bitter taste receptors

Lopinavir and ritonavir (LPV/r) are the primary anti-human immunodeficiency virus (HIV) drugs recommended by the World Health Organization for treating children aged 3 years and above who are infected with the HIV. These drugs are typically available in liquid formulations to aid in dosing for children who cannot swallow tablets. However, the strong bitter taste associated with these medications can be a significant obstacle to adherence, particularly in young children, and can jeopardize the effectiveness of the treatment. Studies have shown that poor palatability can affect the survival rate of HIV-infected children. Therefore, developing more child-friendly protease inhibitor formulations, particularly those with improved taste, is critical for children with HIV. The molecular mechanism by which lopinavir and ritonavir activate bitter taste receptors, TAS2Rs, is not yet clear. In this study, we utilized a calcium mobilization assay to characterize the activation of bitter taste receptors by lopinavir and ritonavir. We discovered that lopinavir activates TAS2R1 and TAS2R13, while ritonavir activates TAS2R1, TAS2R8, TAS2R13, and TAS2R14. The development of bitter taste blockers that target these receptors with a safe profile would be highly desirable in eliminating the unpleasant bitter taste of these anti-HIV drugs.

Genetic variation in sweet taste receptors and a mechanistic perspective on sweet and fat taste sensation in the context of obesity

Taste sensation enables humans to make nutritionally important decisions such as food preference and consumption. It functions as deterministic factors for unpropitious eating behavior, leading to overweight and obesity. The hedonistic feeling on consumption of fat and sugar-rich meals, in particular, has a negative influence on health. In addition, impairment in the taste receptors alters the downstream signaling of taste transduction pathway. Hence, genetic polymorphism in typical taste receptors is a predictor of taste sensitivity variance across individuals. The present review summarizes the effect of a single nucleotide polymorphism (SNP) in sweet taste receptors (T1R2/T1R3) on taste perception among individuals of various body mass index (BMI). Furthermore, in the context of obesity, we discussed the possibility of crosstalk between fat and sweet receptors as well as taste dysfunction in diseased individuals. In overall, a greater understanding of the physiological relationship between taste receptors, altered taste sensitivity, and genetic polymorphisms should lead to more effective obesity prevention approaches.

Single Nucleotide Polymorphisms in Close Proximity to the Fibroblast Growth Factor 21 (FGF21) Gene Found to Be Associated with Sugar Intake in a Swedish Population

Hereditary mechanisms are partially responsible for individual differences in sensitivity to and the preference for sweet taste. The primary aim of this study was to examine the associations between 10 genetic variants and the intake of total sugar, added sugar, and sugars with sweet taste (i.e., monosaccharides and sucrose) in a middle-aged Swedish population. Two single nucleotide polymorphisms (SNPs) within the Fibroblast grow factor 21 (FGF21) gene, seven top hits from a genome-wide association study (GWAS) on total sugar intake, and one SNP within the fat mass and obesity associated (FTO) gene (the only SNP reaching GWAS significance in a previous study), were explored in relation to various forms of sugar intake in 22,794 individuals from the Malmö Diet and Cancer Study, a population-based cohort for which data were collected between 1991-1996. Significant associations (p = 6.82 × 10^-7 - 1.53 × 10^-3) were observed between three SNPs (rs838145, rs838133, and rs8103840) in close relation to the FGF21 gene with high Linkage Disequilibrium, and all the studied sugar intakes. For the rs11642841 within the FTO gene, associations were found exclusively among participants with a body mass index ≥ 25 (p < 5 × 10^-3). None of the remaining SNPs studied were associated with sugar intake in our cohort. A further GWAS should be conducted to identify novel genetic variants associated with the intake of sugar.