Dietary intake and alcohol consumption might be influenced by genetic variations in taste receptor genes. The objectives of this study were to examine the relationship between polymorphisms in the bitter taste receptor genes TAS2R13 (rs1015443) and TAS2R38 (rs1726866, rs10246939, and rs713598) as well as alcohol consumption and body fat percentage in college students. Four hundred and two students with a mean age of 20.2 years participated in this study. An NIH Diet History Questionnaire (DHQ II) was used to collect data on their dietary intake, while an AUDIT survey was used to determine their level of alcohol consumption. Bitter taste receptor gene polymorphisms were assessed by TaqMan allelic discrimination assays. Despite significant associations between TAS2R13 (rs1015443) and certain aspects of alcohol consumption, including the frequency of alcohol intake, no significant associations were found between TAS2R13 (rs1015443) and alcohol consumption after accounting for confounding variables in the regression model. Neither association was found regarding percent of body fat. In contrast, ethnicity and gender significantly influenced percent of body fat (p < 0.001), while no significant association was observed between TAS2R13 (rs1015443) and percent of body fat. Likewise, TAS2R38 (rs1726866, rs10246939, and rs713598) demonstrated no significant association with alcohol consumption and percent of body fat. These results were controlled for confounding factors, such as ethnicity and gender. Body fat percentage and alcohol consumption may be influenced by ethnicity, gender, and age rather than SNPs of TAS2R13 and TAS2R38 genes. Assessing taste genes\' interactions with diet and body composition might be useful in identifying human disease risk.

OBJECTIVE: In this study, we evaluated the influence of taste phenotypes and genotypes on the hedonics of sweetened and unsweetened coffee.
METHODS: Liking of espresso coffee from food questionnaire and of a ready-to-drink unsweetened coffee beverage was measured using a 9-point hedonic scale in 1551 Italian individuals. Perception and liking for different bitter and sweet compounds were also collected. Genotyping of selected Single Nucleotide Polymorphisms (SNPs) in five taste genes (TAS1R3, GNAT3, TAS2R14, TAS2R19, TAS2R38) was performed. Linear and logistic regression models, including sex and gender as covariates, were used to test the relationship of taste phenotypes and selected SNPs with coffee liking.
RESULTS: We found that increased caffeine bitterness perception was associated with an increasing liking for sweetened coffee (p-value = 0.018) and decreased liking of unsweetened coffee (p-value = 0.034). The liking of unsweetened coffee beverage was also negatively associated with sweet intensity perception (p-value = 0.03). Analysis of SNPs in taste-related genes showed that rs6467192 G allele (intron 4 variant) in GNAT3 sweet taste gene was associated with higher liking of sweetened coffee (p-value = 0.002) and lower liking of unsweetened coffee (p-value = 0.01). An association also emerged between unsweetened coffee and SNPs in bitter receptor genes, with rs2597979 in TAS2R14 gene associated with liking of unsweetened coffee (p-value = 0.004) and rs10772420 in TAS2R19 gene associated with liking of both unsweetened espresso coffee and coffee beverage (p-value = 0.04 and p-value = 0.03, respectively).
CONCLUSIONS: These findings suggested that individual preference for sweetened and unsweetened coffee may be influenced by both phenotypic and nucleotide variations in bitter and sweet taste sensitivity.

UNASSIGNED: The aim of the present study was to systematically review the literature investigating the single nucleotide polymorphisms (SNP) related to taste genes and their influence on caries.
UNASSIGNED: Search was performed in five databases to respond to the question: \'Are the polymorphisms of taste genes associated with dental caries?\'. Studies in humans were included. Assessment of quality of studies, meta-analysis and sensitivity analysis were performed.
UNASSIGNED: Seven studies were included in the systematic review and two in meta-analysis. Most of studies (71.4%) presented cohort design with low-level of evidence. A total of 4,032 individuals were evaluated. Four different taste genes (TAS1R2, TAS2R38, TAS1R3 and GLUT2) and 12 SNPs were reported. Most SNPs of taste genes showed a protective effect of the minor allele against dental caries. Meta-analysis included the SNP rs713598 placed in the TAS2R38 gene. The results suggest an effect of the heterozygote genotype (CG), which was associate with low caries experience (OR = 0.35 CI95% [0.17-0.75]). However, the genotype GG was not associated (OR = 0.17 CI95% [0.03-1.04]). Sensitivity analysis showed an important influence of one study in the results.
UNASSIGNED: SNP of taste genes seems to be associated with caries experience. Causal inferences should be interpreted with caution and the results must be replicated in different populations.

Taste and diet preferences are complex and influenced by both environmental and host traits while affecting both food selection and associated health outcomes. The present study genotyped 94 single nucleotide polymorphisms (SNPs) in previously reported taste and food intake related genes and assessed associations with taste threshold (TT) and preferred intensity (PT) of sweet, sour and bitter, food preferences, habitual diet intake, and caries status in healthy young Swedish men and women (n = 127). Polymorphisms in the GNAT3, SLC2A4, TAS1R1 and TAS1R2 genes were associated with variation in TT and PT for sweet taste as well as sweet food intake. Increasing PT for sweet was associated with increasing preference and intake of sugary foods. Similarly, increasing TT for sour was associated with increasing intake of sour foods, whereas the associations between food preference/intake and TT/PT for bitter was weak in this study group. Finally, allelic variation in the GNAT3, SLC2A2, SLC2A4, TAS1R1 and TAS1R2 genes was associated with caries status, whereas TT, PT and food preferences were not. It was concluded that variations in taste receptor, glucose transporter and gustducin encoding genes are related to taste perception, food preference and intake as well as the sugar-dependent caries disease.