Abstract
Psychological stress disrupts the integrity of the intestinal barrier and is strongly linked to emotional disorders, behavioral changes, and gastrointestinal dysfunction. However, there are limited treatment options available for repairing the damage to the intestinal barrier. As a natural plant-based health beverage, tea (Camellia sinensis) has been shown to have various potentially advantageous effects on the intestinal barrier and immune function. In this study, we extracted bioactive molecules from tea leaves, named exosome-like nanoparticles (ELNs), and then examined their potential protective properties for the intestinal barrier. Through in vitro experimentation, we investigated whether tea-derived ELNs (TELNs) could offer a protective effect against lipopolysaccharides-induced damage to the intestinal barrier. In an in vivo experiment, rats were exposed to water avoidance stress and subsequently administered TELNs orally. The administration of TELNs resulted in the enhancement of the epithelial barrier in the intestine, effectively preventing bacterial translocation to the submucosae. Additionally, TELNs were found to improve the function of the intestinal immune barrier through the mediation of interleukin-22 and the increased secretion of antimicrobial peptide Reg3g. Notably, miR-44 and miR-54 in TELNs exhibited similar protective effects on the intestinal barrier. These findings suggest that TELNs possess the ability to restore the integrity of the intestinal barrier in the context of psychological stress.