Orosensory detection of bitter in fat-taster healthy and obese participants: Genetic polymorphism of CD36 and TAS2R38

Abstract

We assessed orosensory detection of a long-chain fatty acid, linoleic acid (LA), and a bitter taste marker, 6-n-propylthiouracil (PROP), and correlated lipid-taster subjects with PROP detection and polymorphism in genes encoding bitter and lipid taste receptors, respectively, TAS2R38 and CD36, in normal weight and obese subjects. The normal weight (n=52, age=35.3±4.10 years, BMI=23.22±1.44kg/m2) and obese (n=52, age=35.0±5.43 years, BMI=34.29±5.31kg/m2) participants were recruited to determine fat and bitter detection thresholds. The genomic DNA was used to determine single nucleotide polymorphism (SNP) of CD36 (rs1761667) and TAS2R38 (rs1726866 and rs10246939). The study included the participants who could detect LA, i.e., lipid-tasters. There was a positive correlation between BMI and detection thresholds for fat and bitter taste in normal weight and obese subjects. Obese participants showed a positive correlation between LA and PROP detection thresholds. PROP detection thresholds were higher for CD36 SNP (rs1761667) and TAS2R38 SNPs (rs1726866 and rs10246939) in obese participants compared to normal weight subjects. LA detection thresholds were not high for CD36 SNP (rs1761667) or TAS2R38 SNP (rs1726866 and rs10246939) in obese participants. Orosensory detection thresholds for fat and bitter taste are associated with BMI, and CD36 and TAS2R38 genotypes are not always associated with taste phenotypes.