Acute Cold Water-Immersion Restraint Stress Induces Intestinal Injury and Reduces the Diversity of Gut Microbiota in Mice

Abstract

Growing evidence has demonstrated that stress triggers gastrointestinal (GI) disorders. This study aimed to investigate how the acute cold water-immersion restraint (CWIR) stress affects intestinal injury and gut microbiota (GM) distribution. Male C57BL/6 mice were used to establish a CWIR animal model. Hematoxylin–eosin and periodic acid–Schiff staining were performed to assess intestinal histopathological changes. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) analysis and immunofluorescence staining were used to evaluate the expression of inflammatory cytokines and immune cell infiltration in the intestinal tissues. The gut permeability and intestinal occludin protein expression were determined through fluorescein isothiocyanate-dextran detection and western blot, respectively. GM profiles were analyzed via high-throughput sequencing of the fecal bacterial 16S rRNA genes. Results showed that CWIR induced more severe intestinal mucosal injury compared to the control, leading to a significant increase in tumor necrosis factor-α expression, but no infiltration of neutrophil and T cells. CWIR also resulted in GI disruption and increased the permeability of the intestinal mucosa. GM profiles showed that CWIR reduced GM diversity of mice compared with the control group. Specifically, aerobic and gram-negative bacteria significantly increased after CWIR, which was associated with the severity of gut injury under stress. Therefore, acute CWIR leads to severe intestinal damage with inflammation and disrupts the GM homeostasis, contributing to decreased GM diversity. Our findings provide the theoretical basis for the further treatment of intestinal disorders induced by CWIR.

Review of the relationship and underlying mechanisms between the Qinghai–Tibet plateau and host intestinal flora

“…Exposure to cold environments can reduce the abundance of the intestinal flora. The abundance of intestinal flora decreased after being soaked in cold water for 1 h ( Zhang et al, 2021 ). Furthermore, Zietak et al (2016) housed mice in a cold environment and observed a decrease in the abundance of their intestinal flora.…”

Regulation of the central amygdala on intestinal motility and behavior via the lateral hypothalamus in irritable bowel syndrome model mice

“…Although the pathophysiology of IBS remains unclear, one major cause has been attributed to psychosocial stress from various sources. Studies showed that acute cold WIRS could cause IBS‐like disorders, increase the permeability of intestinal mucosa, and cause severe intestinal inflammation and injury 49 . Six or seven hours daily WIRS could induce gastric ulcers, 50,51 however, Yasugaki et al confirmed that the use of a milder regimen did not lead to gastric ulcers, 40 and this approach could lead to anxiety‐depression‐like phenotypes and gastrointestinal dysfunction.…”

Knockout of IL-6 mitigates cold water-immersion restraint stress-induced intestinal epithelial injury and apoptosis

“…All animals were housed in a 12 h day-night cycle with free access to water and food at 22 ± 1°C and 60 ± 10% humidity. The mice in corresponding groups were administrated with acute CWIR for 1 h using the same protocol described in our previous study (13). Briefly, mice were restrained in polyvinyl chloride tubes and vertically immersed in cold water with a temperature around 10°C, at the level of sternum xiphoid.…”

“…Although acute stress frequently causes gastrointestinal (GI) dysfunction, few studies have reported CWIR-induced intestinal damage and manifestations. We previously uncovered that acute CWIR resulted in damaged intestinal mucosa and decreased gut microbiota diversity (13), implying that stress-induced intestinal disorders exist.…”