Dietary supplementation with selenium nanoparticles-enriched Lactobacillus casei ATCC 393 alleviates intestinal barrier dysfunction of mice exposed to deoxynivalenol by regulating endoplasmic reticulum stress and gut microbiota

Deoxynivalenol (DON), a secondary product of Fusarium metabolism, is common in wheat, corn, barley and other grain crops, posing a variety of adverse effects to environment, food safety, human and animal health. The absorption of DON mainly occurs in the proximal part of the small intestine, which can induce intestinal mucosal epithelial injury, and ultimately affect the growth performance and production performance of animals. This study was conducted to investigate the protective effects of selenium nanoparticles (SeNPs)-enriched Lactobacillus casei ATCC 393 (L. casei ATCC 393) on intestinal barrier function of C57BL/6 mice exposed to DON and its association with endoplasmic reticulum stress (ERS) and gut microbiota. The results showed that DON exposure increased the levels of interleukin-6 (IL-6) and interleukin-8 (IL-8), decreased the levels of interleukin-10 (IL-10) and transforming growth factor beta (TGF-β), caused a redox imbalance and intestinal barrier dysfunction, decreased the mRNA levels of endoplasmic reticulum- resident selenoproteins, activated ERS-protein kinase R-like endoplasmic reticulum kinase (PERK) signaling pathway, altered the composition of the gut microbiota and decreased short-chain fatty acids (SCFAs) content. Dietary supplementation with SeNPs-enriched L. casei ATCC 393 can effectively protect the integrity of intestinal barrier function by reducing inflammatory response, enhancing the antioxidant capacity, up-regulating the mRNA levels of endoplasmic reticulum-resident selenoproteins, inhibiting the activation of PERK signaling pathway, reversing gut microbiota dysbiosis and increasing the content of SCFAs in mice exposed to DON. In conclusion, dietary supplementation with SeNPs-enriched L. casei ATCC 393 effectively alleviated intestinal barrier dysfunction induced by DON in C57BL/6 mice, which may be closely associated with the regulation of ERS and gut microbiota