Abstract: Objective　To investigate the effects of chronic restraint stress on the gut microbiota in depressive model mice and its association with behavioral phenotypes.Methods　Twenty-four C57BL/6 mice were randomly assigned to a control group (n=12) and a model group (n=12). The control group was housed under standard conditions, while the model group received chronic restraint stress intervention. Body weight was monitored, and behavioral characteristics were assessed using the open field test and the sucrose preference test. The composition of gut microbiota was analyzed by 16S rRNA gene sequencing, and differences in microbial community diversity and structure between the two groups were compared.Results　Compared with control group, model group showed a significant slowdown in body weight gain, along with significantly reduced locomotor and exploratory activity in the open field test and a decreased sucrose preference index (P<0.05). Gut microbiota analysis revealed that the richness and diversity of microbial community were significantly lower in model group (P<0.05). The relative abundance ratio of Bacteroidetes to Firmicutes was significantly altered, and marked fluctuations were observed in the abundance of specific bacterial genera.Conclusion　Chronic restraint stress may induce gut microbiota dysbiosis, which could be involved in the occurrence of depressive-like behaviors. These findings suggest that gut microbes may influence central emotional regulation via the gut-brain axis.

Key words: chronic restraint stress, gut microbiota, 16S rRNA sequencing

摘要： 目的　探讨慢性束缚应激对抑郁模型小鼠肠道菌群的影响及其与行为表型的关联。方法　将24只C57BL/6 小鼠随机分为正常组(n=12)与模型组(n=12),正常组于标准条件下饲养,模型组接受慢性束缚应激干预。监测 小鼠体质量变化,并通过旷场实验和糖水偏好实验评估小鼠行为学特征。采用16S rRNA基因测序技术分析小鼠 肠道菌群组成,比较两组间微生物群落多样性及结构的差异。结果　与正常组相比,模型组小鼠体质量增长显著 减缓,旷场实验中的运动探索能力及糖水偏好指数均显著降低(P<0.05)。肠道菌群分析表明,模型组小鼠微生物 群落的丰富度与多样性显著降低(P<0.05),拟杆菌门与厚壁菌门的相对丰度比例发生显著改变,特定菌属丰度呈 现明显波动。结论　慢性束缚应激诱导的肠道菌群失调可能参与抑郁样行为的发生,提示肠道微生物或通过肠 脑轴影响中枢情绪调控。

关键词: 慢性束缚应激, 肠道菌群, 16S rRNA测序