Helmholtz-Institute for Metabolic, Obesity and Vascular Research (HI-MAG), Helmholtz Center Munich at the University of Leipzig and the University Hospital Leipzig AöR, 04103 Leipzig, Germany.
Institute of Anatomy, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany.
Nutrients. 2024 Aug 9;16(16):2633. doi: 10.3390/nu16162633.
Saliva is essential for the proper dilution and distribution of taste molecules on the tongue. It harbors extracellular vesicles (EVs), which mediate cell-cell communication. Changes in the composition of salivary EVs may arise under obese conditions and may potentially be involved in taste sensation and dysregulated eating behavior. Therefore, this study addresses the relationship between the size and concentration of salivary EVs and metabolic shifts in obesity or factors of taste sensation.
A total of 119 participants in the Obese Taste Bud (OTB) Study were included, who performed a standardized taste test, underwent taste bud density assessment, and were phenotypically characterized for anthropometrics, blood- and saliva adipokine levels, and various metabolic factors. Utilizing size exclusion chromatography followed by ultrafiltration, EVs were extracted from 2 mL of actively secreted saliva. EVs were characterized using nanoparticle tracking analyses, Western blot, and scanning transmission electron microscopy. Finally, group comparisons and bivariate correlation analyses were conducted.
Among the total cohort, the median size of salivary EVs was 190.05 nm, and the overall concentration ranged from 1.4 × 10 to 1.76 × 10 per mL of saliva. The size range and concentration of EVs per mL are negatively correlated ( = 0.0002, r = -0.264). Comparing lean participants (mean rank of 45.98) with those presenting obesity (mean rank of 34.46), a significant difference in the salivary EV content was observed ( = 0.029). Body weight, BMI, arm and calf circumferences, as well as the percentage of body fat were all negatively related to the concentration of EVs in all study participants (all < 0.05, r > -0.2). No associations were found between the EV parameters and taste perception but serum alkaline phosphatase levels were negatively correlated ( = 0.007, r = -0.284) and adiponectin serum levels were positively correlated to the EV concentration ( = 0.036, r = 0.208).
The current study provides evidence for the relation between salivary EVs and anthropometric as well as metabolic parameters of obesity. This can provide the basis for further research on the cargo of salivary EVs and how they may influence taste sensation, and may elucidate their potential connection to altered eating habits in obesity.
唾液对于舌头上味觉分子的适当稀释和分布至关重要。它含有细胞外囊泡（EVs），这些囊泡介导细胞间通讯。肥胖条件下唾液 EVs 的组成可能发生变化，并且可能潜在地参与味觉感知和失调的进食行为。因此，本研究旨在探讨唾液 EVs 的大小和浓度与肥胖相关的代谢变化或味觉感知因素之间的关系。
共纳入 119 名肥胖味蕾（OTB）研究参与者，他们进行了标准化味觉测试，接受了味蕾密度评估，并对人体测量学、血液和唾液脂肪因子水平以及各种代谢因素进行了表型特征分析。使用大小排阻色谱法和超滤法从 2ml 主动分泌的唾液中提取 EVs。使用纳米颗粒跟踪分析、Western blot 和扫描透射电子显微镜对 EVs 进行表征。最后，进行了组间比较和双变量相关分析。
在总队列中，唾液 EVs 的中位大小为 190.05nm，总体浓度范围为每毫升唾液 1.4×10 至 1.76×10。EVs 的大小范围和每毫升浓度呈负相关（ = 0.0002，r = -0.264）。与瘦参与者（平均秩为 45.98）相比，肥胖参与者（平均秩为 34.46）的唾液 EV 含量存在显著差异（ = 0.029）。体重、BMI、臂围和小腿围，以及体脂肪百分比均与所有研究参与者的 EV 浓度呈负相关（均 < 0.05，r > -0.2）。EV 参数与味觉感知之间无关联，但血清碱性磷酸酶水平与 EV 浓度呈负相关（ = 0.007，r = -0.284），血清脂联素水平与 EV 浓度呈正相关（ = 0.036，r = 0.208）。
本研究为唾液 EVs 与肥胖的人体测量和代谢参数之间的关系提供了证据。这可为进一步研究唾液 EVs 的货物以及它们如何影响味觉感知提供基础，并可能阐明它们与肥胖改变饮食习惯之间的潜在联系。
