Division of Human Nutrition and Health, Wageningen University & Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
Wageningen Plant Research, Wageningen University & Research, P.O. Box 16, 6700 AA Wageningen, The Netherlands.
Food Funct. 2022 Aug 15;13(16):8399-8410. doi: 10.1039/d2fo01358d.
Gamma-aminobutyric acid (GABA) and its precursor glutamate play signaling roles in a range of tissues. Both function as neurotransmitters in the central nervous system, but they also modulate pancreatic and immune functioning, for example. Besides endogenous production, both compounds are found in food products, reaching relatively high levels in tomatoes. Recent studies in rodents suggest beneficial effects of oral GABA on glucose homeostasis and blood pressure. However, the bioavailability from food remains unknown. We studied the bioavailability of GABA and glutamate from tomatoes relative to a solution in water. After a fasting blood sample was taken, eleven healthy men randomly received 1 liter of 4 different drinks in a cross-over design with a one-week interval. The drinks were a solution of 888 mg L GABA, a solution of 3673 mg L glutamate, pureed fresh tomatoes and plain water as the control. Following intake, 18 blood samples were taken at intervals for 24 hours. Plasma GABA and glutamate concentrations were determined by ultra-pressure liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). Fasting plasma GABA and glutamate concentrations were found to be 16.71 (SD 2.18) ng mL and 4626 (SD 1666) ng mL, respectively. Fasting GABA levels were constant (5.8 CV%) between individuals, while fasting glutamate levels varied considerably (23.5 CV%). GABA from pureed tomatoes showed similar bioavailability to that of a solution in water. For glutamate, the absorption from pureed tomatoes occurred more slowly as seen from a longer (0.98 ± 0.14 h 0.41 ± 0.04 h, = 0.003) and lower (7815 ± 627 ng mL 16 420 ± 2778 ng mL, = 0.006). These data suggest that GABA is bioavailable from tomatoes, and that food products containing GABA could potentially induce health effects similar to those claimed for GABA supplements. The results merit further studies on the bioavailability of GABA from other food products and the health effects of GABA-rich diets. The clinical trial registry number is NCT04086108 (https://clinicaltrials.gov/ct2/show/NCT04303468).
γ-氨基丁酸（GABA）及其前体谷氨酸在多种组织中发挥信号作用。它们在中枢神经系统中均作为神经递质发挥功能，但也可调节胰腺和免疫功能等。除内源性产生外，这两种化合物都存在于食品中，在番茄中含量相对较高。最近在啮齿动物中的研究表明，口服 GABA 对葡萄糖稳态和血压具有有益作用。然而，食物中的生物利用度尚不清楚。我们研究了番茄中 GABA 和谷氨酸相对于水相溶液的生物利用度。禁食血样采集后，11 名健康男性以交叉设计随机接受 1 升 4 种不同的饮料，间隔 1 周。这 4 种饮料分别为 888 mg/L GABA 溶液、3673 mg/L 谷氨酸溶液、鲜番茄泥和普通水。摄入后，24 小时内每隔 18 小时采集 18 份血样。采用超高效液相色谱-串联质谱法（UPLC-MS/MS）测定血浆 GABA 和谷氨酸浓度。空腹时血浆 GABA 和谷氨酸浓度分别为 16.71（SD 2.18）ng/ml 和 4626（SD 1666）ng/ml。空腹时 GABA 水平在个体间保持恒定（5.8%CV%），而空腹时谷氨酸水平变化较大（23.5%CV%）。鲜番茄泥中的 GABA 与水相溶液具有相似的生物利用度。对于谷氨酸，从鲜番茄泥中的吸收较慢，从更长的时间（0.98±0.14 h 比 0.41±0.04 h，=0.003）和更低的水平（7815±627 ng/ml 比 16420±2778 ng/ml，=0.006）可以看出。这些数据表明，番茄中的 GABA 是可生物利用的，并且含有 GABA 的食品可能会产生类似于 GABA 补充剂所声称的健康作用。这些结果值得进一步研究其他食品中 GABA 的生物利用度以及富含 GABA 的饮食对健康的影响。临床试验注册号为 NCT04086108（https://clinicaltrials.gov/ct2/show/NCT04303468）。
