抑郁症是一种常见的精神疾病，通常与性别、遗传、环境或心理原因有关。肠道菌群可参与人体的众多生理调节，对情绪状态和行为认知方面发挥重要作用。健康的肠道微生物群主要以拟杆菌门和厚壁菌门为主要优势菌门，而抑郁症患者的肠道微生物丰富度和多样性较正常人相比显著降低。研究发现肠道微生物群通过神经、免疫和代谢途径直接或间接与大脑进行双向沟通，肠道菌群变化与抑郁症之间存在明显的相关性。因此，保持健康的肠道微生物群对大脑健康极其重要。该研究主要基于肠-脑轴探讨抑郁症的可能发病机制，分别从肠道菌群影响单胺类神经递质的产生、改变神经系统可塑性、诱使炎症因子水平变化以及导致下丘脑-垂体-肾上腺轴功能紊乱等4个方面对抑郁症的作用进行讨论。此外，该研究还总结了几种调节肠道菌群干预抑郁症的可能途径，以期为治疗抑郁症提供新的思路。

Depression is a common mental illness that is often linked to sex, genetics, and environmental or psychological causes. The gut microbiota plays an important role in emotional state and behavioral cognition by participating in many forms of the physiological regulation of the human body. Bacteroidetes and Firmicutes are the dominant phyla in healthy gut microbiota; the richness and diversity of the gut microbiota are substantially lower in patients with depression than those in healthy people. The gut microbiota directly or indirectly communicates with the brain through neural, immune, and metabolic pathways, and a strong correlation exists between changes in the gut microbiota and depression. Therefore, maintaining a healthy gut microbiome is extremely important for brain health. This study mainly explored the possible pathogenesis of depression based on the gut–brain axis, and the effects of gut microbiota on depression were discussed from four aspects: affecting monoamine neurotransmitter production, changing the plasticity of the nervous system, inducing changes in the levels of inflammatory factors, and causing dysfunction of the hypothalamus-pituitary-adrenal axis. In addition, several possible methods of regulating the gut microbiota to intervene in depression were summarized to provide new ideas for the treatment of depression.

上海市普陀区科技研发平台项目（2022QX01）