Chronic stress which changed the intestinal permeability and induced inflammation was restored by E2

Chronic psychological stress has an impact on the health of both humans and animals, particularly females and pregnant individuals. In this study, we established a stress-induced model by subjecting 8-week-old female mice and pregnant mice to a 4-hour confinement in centrifuge tubes. The aim was to investigate the effects of chronic stress on the intestinal mucosal barrier and microbiota composition in pregnant mice. Comparing the stress group with the control group, we observed significant increases in NE, CORT, and E2 levels in the plasma of the stressed mice. Furthermore, we observed a down-regulation of anti-inflammatory cytokines and an up-regulation of pro-inflammatory cytokines, leading to colonic mucosal injury. This injury included a decrease in the number of goblet cells, proliferating cell nuclear antigen-positive cells, caspase-3 expression, and the expression of tight junction mRNA and protein. Additionally, we found that the diversity and richness of the colonic microbiota were reduced in pregnant mice, with a decrease in Bacteroidetes and a marked increase in harmful bacteria. Finally, we discovered that E2 provides protection for intestinal epithelial cells following H2O2 treatment. The results suggest that an E2 concentration of 25 pg/mL offers better protection for the intestine under conditions of chronic stress, which significantly affects the intestinal mucosal barrier and alters the composition of the colonic microbiota.