Disrupted microbiota-barrier-immune interaction in phthalates-mediated barrier defect in the duodenum.

As one of the most used phthalates, Di (2-ethylhexyl) phthalate (DEHP) is a widespread environmental contaminant. Extremely persistent plastic can enter the food chain of animals through the aquatic environment, affect metabolic pathways and cause damage to the digestive system. But the molecular mechanism of its toxic effects on the duodenum in birds has not been elucidated. To investigate the toxicity of phthalates in the duodenum, quails were gavaged with 250, 500, and 750 mg/kg doses of DEHP for 45 days, and water and oil control groups were retained. This study revealed that subchronic exposure to DEHP could lead to duodenal barrier defect in quail. The damage to duodenum was reflected in a reduction in V/C and tight junction proteins. Moreover, DEHP also led to a breakdown of antimicrobial defenses through the flora derangement, which acted as a biological barrier. The massive presence of Lipopolysaccharide (LPS) led to the activation of TLR4 receptors. In addition, DEHP activated oxidative stress, which synergized the inflammatory response induced by the TLR4-NFκB pathway, and further promoted duodenum damage. This study provides a base for the further effect of phthalates on the microbiota-barrier-immune interaction. DEHP (a commonly used phthalate) induced duodenal barrier defect and flora derangement of quail, which is sensitive to environmental pollutants. This study provides a base for the further effect of phthalates on the microbiota-barrier-immune interaction. [Display omitted] • Duodenal barrier defect disrupts microbiota-barrier-immune interaction. • DEHP causes duodenal flora derangement and dysbiosis of antimicrobial function. • Duodenal Proteobacteria increased most significantly after DEHP treatment. • DEHP induces duodenum damage and decreases V/C in quail. • DEHP activates duodenal oxidative stress and inflammation in quail. DEHP (a commonly used phthalate) is ubiquitous in the environment due to overuse. This study could warn of the health risks to animals exposed to phthalates and even humans. [ABSTRACT FROM AUTHOR]