微生物群落和紧密连接蛋白（TJP）是肠道屏障的组成部分，被认为是压力靶标，对肠道内稳态产生有害影响。本研究旨在评估慢性固定应激对选定的小肠稳态参数的影响。女性BALB/c小鼠被分为应激组和非应激对照组，应激组每天固定2小时，连续4天，去掉近端和远端小肠样本以评估选择性琼脂平板上每克总双歧杆菌的菌落形成单位（CFU/g），使用免疫酶法评估腔道白蛋白，使用反转录定量聚合酶链式反应（RT-qPCR）评估促炎细胞因子，并使用RT-qPCR和Western印迹检测TJPs（孔形成的，Cld-2；密封孔的，Cld-4；含糊不清的，Cld-7、-12和-15）。与对照组相比，应激组的体重和能量摄入量较低。在远端区域，应激小鼠的双歧杆菌计数和Cld-2、Cld-4和Cld-12的信使核糖核酸（mRNA）表达较低，尽管它们的白蛋白和白细胞介素（IL）-6 mRNA表达较高。在近端区域内，应激小鼠表现出肿瘤坏死因子α（TNF-α）、γ干扰素（IFN-γ）、IL-6、Cld-7、Cld-12和Cld-15 mRNA表达水平升高，同时IL-10和Cld-4水平降低。然而，TJPs的mRNA和蛋白表达不一致。这些发现表明应激对小肠产生不同的反应，表现为在十二指肠中诱导促炎反应和降低抗炎反应，并在远端区域中增加白蛋白外渗和减少双歧杆菌生长。

Microbiota and tight junction proteins (TJPs) are components of the gut barrier, and are considered stress targets that have deleterious effects on intestinal homeostasis.This study aimed to evaluate the effects of chronic immobilization stress on selected small intestine homeostasis parameters.Female BALB/c mice were divided into a stress group that underwent short-term immobilization for 2 h per day for 4 consecutive days, and a non-stressed control group (n = 6 per group). Proximal and distal small intestine samples were excised to assess colony-forming units per gram (CFU/g) of total bifidobacteria in selective agar plates, luminal albumin was assessed using immune-enzymatic assay, pro-inflammatory cytokines were evaluated using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and TJPs (pore-forming, claudin (Cld)-2; pore-sealing, Cld-4; ambiguous, Cld-7, -12 and -15) were assessed with RT-qPCR and western blotting.Compared with the control group, the stress group had lower body weight and energy intake. In the distal region, the stressed mice had lower bifidobacteria count and messenger ribonucleic acid (mRNA) expression of Cld-2, Cld-4 and Cld-12, though they had more albumin and higher interleukin (IL)-6 mRNA expression. Within the proximal region, the stressed mice had higher mRNA expression of tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), IL-6, Cld-7, Cld-12, and Cld-15, along with lower levels of IL-10 and Cld-4. However, mRNA and protein expression of TJPs were discordant.These findings indicate divergent stress-induced outcomes in the small intestine, evidenced by the elicitation of a pro-inflammatory response and decreased anti-inflammatory response in the duodenum, and by increased albumin transudation and decreased bifidobacterial growth in the distal region.