Presentation Details
Bitter Taste Hyper-Sensitivity to Quinine and Amarogentin Is Associated with Food Allergies

Zeping Shao1, Yun Liu2, Nadia de Jager3, Eugeni Roura1.

1Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Australia.2Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Australia.3Queensland Brain Institute, The University of Queensland, Brisbane, Australia

Abstract


Food allergies have been defined as an immune response occurring soon after ingesting an otherwise innocuous, dietary protein. The activation of immune cells (i.e. T lymphocytes) occur after activation by specific peptides (referred to as epitopes) part of the amino acid sequence of the protein. Interestingly, several peptides have been identified as bitter receptor (TAS2R) agonists. For example, Gly-Phe-containing peptides have been identified as epitopes involved in peanut, tree nut, milk, and egg allergies among others. Interestingly, Gly-Phe is a high affinity ligand for TAS2R4. With the hypothesis that sensitivity to bitterants may be involved in food allergic responses, we performed sensory evaluations on 16 medically diagnosed food allergic (FA) and 16 non-food allergy (NFA) participants. Best estimate thresholds (BET) for quinine hydrochloride (quinine), amarogentin, thiamine hydrochloride (thiamine), 6-n-propylthiouracil (PROP) and caffeine were analyzed via discriminatory triangle test. The BET were significantly (P = 0.0226, one-way ANOVA) or tended to be (P = 0.0671) lower in FA group compared to NFA individuals for quinine and amarogentin, respectively. In contrast, no significant (P > 0.10) differences were observed related to the sensing of thiamine, PROP, or caffeine between the two groups. Quinine and amarogentin show high affinity to TAS2R4. Thus, it would appear that the bitter-hypersensitivity involving TAS2R4 observed in FA individuals may be related to a defensive response to avoid consumption of potential allergenic proteins. In conclusion, a significant hyper-sensitivity to bitter TAS2R4 ligands has been identified in FA compared to NFA volunteers. The potential role of TAS2R4 and other TAS2Rs in food allergies warrants further investigation.

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