The non-tasting form of the bitter taste receptor, TAS2R38, has been shown as a genetic risk factor associated with the development of Parkinson's disease (PD). Specific taste receptors that are expressed in the lower gastrointestinal tract may respond to alteration in gut microbiota composition, detecting bacterial molecules, and regulate immune responses. Given the importance of brain-gut-microbiota axis and gene-environment interactions in PD, we investigate the associations between the genetic variants of TAS2R38 and gut microbiota composition in 39 PD patients. The results confirm that the majority of PD patients have reduced sensitivity to 6-n-propylthiouracil (PROP) and are carriers of at least one non-functional TAS2R38 AVI haplotype. Moreover, we found this correlation to be associated with a reduction in bacteria alpha-diversity with a predominant reduction of Clostridium genus. We hypothesised that the high frequency of the non-taster form of TAS2R38 associated with a diminuition of Clostridium bacteria in PD might determine a reduction in the activation of protective signalling-molecules useful in preserving gut homeostasis. This pilot study, by identifying a decrease in specific bacteria associated with a reduced sensitivity to PROP, adds essential information that opens new avenues of research into the association of PD microbiota composition and sensory modification.

苦味受体TAS2R38的非品尝形式已显示为与帕金森氏病（PD）发生有关的遗传危险因素。在下消化道中表达的特定味觉受体可能会对肠道菌群组成的变化作出反应，检测细菌分子并调节免疫反应。考虑到PD中脑肠道菌群轴和基因-环境相互作用的重要性，我们调查了39名PD患者中TAS2R38的遗传变异与肠道菌群组成之间的关联。结果证实，大多数PD患者对6-正丙基硫氧嘧啶（PROP）的敏感性降低，并且是至少一种无功能TAS2R38的携带者AVI单倍型。此外，我们发现这种相关性与细菌α多样性的减少以及梭状芽胞杆菌属的减少有关。我们假设，TAS2R38的非品尝形式的高频率与PD中梭状芽胞杆菌的减少有关，可能决定了用于维持肠道稳态的保护性信号分子的激活减少。这项初步研究通过确定特定细菌的减少与对PROP敏感性的降低相关，增加了必要的信息，为PD微生物群组成与感觉修饰之间的联系开辟了新的研究途径。