Ethyl Acetate Fraction from Eucommia ulmoides Ameliorates Particulate Matter (PM)2.5-Induced Intestinal Damage by Restoring Barrier Integrity and Regulating Inflammatory Responses.

This study investigated the protective effect of ethyl acetate fraction from Eucommia ulmoides leaf (EFEL) against intestinal dysfunction induced by chronic exposure to particulate matter (PM)_2.5 in BALB/c mice. EFEL treatment suppressed reactive oxygen species (ROS) production and cellular death from PM_2.5-induced HT29 cells. EFEL supplementation ameliorated PM_2.5-induced intestinal damage by regulating antioxidant biomarkers, including reduced glutathione and superoxide dismutase, malondialdehyde levels, and myeloperoxidase activity. EFEL modulated the gut microbiota composition by increasing beneficial bacteria, such as Lactobacillus and Alistipes, and reducing the abundance of pathogenic bacteria, such as Helicobacter and Clostridia UCG-014, thus contributing to the restoration of the intestinal microenvironment. Furthermore, EFEL regulated the expression of tight junction proteins and inflammatory biomarkers in intestinal tissue. These findings suggest that EFEL may serve as a promising functional food material with the potential to alleviate PM_2.5-induced intestinal barrier dysfunction by regulating oxidative stress, inflammation, and microbiota homeostasis.