Diabetes mellitus (DM) is a chronic disease characterized by elevated blood glucose levels caused by a lack of insulin production (type 1 diabetes) or insulin resistance (type 2 diabetes). It is well known that DM is associated with cognitive deficits and metabolic and neurophysiological changes in the brain. Glutamate is the main excitatory neurotransmitter in the central nervous system that plays a key role in synaptic plasticity, learning, and memory processes. An increasing number of studies have suggested that abnormal activity of the glutamatergic system is implicated in the pathophysiology of DM. Dysfunction of glutamatergic neurotransmission in the central nervous system can provide an important neurobiological substrate for many disorders. Magnetic resonance spectroscopy (MRS) is a non-invasive technique that allows a better understanding of the central nervous system factors by measuring in vivo the concentrations of brain metabolites within the area of interest. Here, we briefly review the MRS studies that have examined glutamate levels in the brain of patients with DM. The present article also summarizes the available data on abnormalities in glutamatergic neurotransmission observed in different animal models of DM. In addition, the role of gut microbiota in the development of glutamatergic alterations in DM is addressed. We speculate that therapeutic strategies targeting the glutamatergic system may be beneficial in the treatment of central nervous system-related changes in diabetic patients.

糖尿病 (DM) 是一种慢性疾病，其特征是由于胰岛素生成不足（1 型糖尿病）或胰岛素抵抗（2 型糖尿病）导致血糖水平升高。众所周知，糖尿病与认知缺陷以及大脑代谢和神经生理学变化有关。谷氨酸是中枢神经系统中主要的兴奋性神经递质，在突触可塑性、学习和记忆过程中发挥着关键作用。越来越多的研究表明谷氨酸能系统的异常活性与糖尿病的病理生理学有关。中枢神经系统谷氨酸能神经传递功能障碍可为许多疾病提供重要的神经生物学基础。磁共振波谱 (MRS) 是一种非侵入性技术，通过体内测量感兴趣区域内脑代谢物的浓度，可以更好地了解中枢神经系统因素。在这里，我们简要回顾一下检查糖尿病患者大脑中谷氨酸水平的 MRS 研究。本文还总结了在不同 DM 动物模型中观察到的谷氨酸能神经传递异常的现有数据。此外，还讨论了肠道微生物群在糖尿病谷氨酸能改变发展中的作用。我们推测，针对谷氨酸能系统的治疗策略可能有益于治疗糖尿病患者中枢神经系统相关的变化。