Gamma-aminobutyric acid (GABA) plays a crucial role in the central nervous system as an inhibitory neurotransmitter. Imbalances of this neurotransmitter are associated with neurological diseases, such as Alzheimer’s and Parkinson’s disease, and psychological disorders, including anxiety, depression, and stress. Since GABA has long been believed to not cross the blood–brain barrier, the effects of circulating GABA on the brain are neglected. However, emerging evidence has demonstrated that changes in both circulating and brain levels of GABA are associated with changes in gut microbiota composition and that changes in GABA levels and microbiota composition play a role in modulating mental health. This recent research has raised the possibility that GABA may be a potent mediator of the gut–brain axis. This review article will cover up-to-date information about GABA-producing microorganisms isolated from human gut and food sources, explanation why those microorganisms produce GABA, food factors inducing gut–GABA production, evidence suggesting GABA as a mediator linking between gut microbiota and mental health, including anxiety, depression, stress, epilepsy, autism spectrum disorder, and attention deficit hyperactivity disorder, and novel information regarding homocarnosine-a predominant brain peptide that is a putative downstream mediator of GABA in regulating brain functions. This review will help us to understand how the gut microbiota and GABA-homocarnosine metabolism play a significant role in brain functions. Nonetheless, it could support further research on the use of GABA production-inducing microorganisms and food factors as agents to treat neurological and psychological disorders.

γ-氨基丁酸（GABA）作为抑制性神经递质在中枢神经系统中发挥着至关重要的作用。这种神经递质的失衡与阿尔茨海默病和帕金森病等神经系统疾病以及焦虑、抑郁和压力等心理障碍有关。由于长期以来人们认为 GABA 不会穿过血脑屏障，因此循环 GABA 对大脑的影响被忽视了。然而，新出现的证据表明，循环和大脑中 GABA 水平的变化与肠道微生物群组成的变化有关，并且 GABA 水平和微生物群组成的变化在调节心理健康方面发挥着作用。这项最近的研究提出了 GABA 可能是肠-脑轴的有效调节剂的可能性。这篇综述文章将涵盖从人类肠道和食物来源中分离出的产生 GABA 的微生物的最新信息，解释这些微生物产生 GABA 的原因，诱导肠道 GABA 产生的食物因素，表明 GABA 作为肠道微生物群和肠道菌群之间联系的介质的证据。心理健康，包括焦虑、抑郁、压力、癫痫、自闭症谱系障碍和注意力缺陷多动障碍，以及有关高肌肽的新信息——高肌肽是一种主要的脑肽，被认为是调节大脑功能的 GABA 下游介质。这篇综述将帮助我们了解肠道微生物群和 GABA-高肌肽代谢如何在大脑功能中发挥重要作用。尽管如此，它可以支持进一步研究使用 GABA 产生诱导微生物和食物因子作为治疗神经和心理疾病的药物。