Lactobacillus reuteri improves function of the intestinal barrier in rats with acute liver failure through Nrf-2/HO-1 pathway.

Objectives: We aimed to explore whether Lactobacillus reuteri could have a positive role in reducing inflammation and bacterial translocation in rats with acute liver failure.
Methods: Lactobacillus reuteri were gavaged to Sprague-Dawley (SD) rats at a dose of 1 × 10 ⁹ CFU/mL once a day for 14 d. D-galactosamine was injected intraperitoneally to induce acute liver failure for 24 h on the 15th day. Liver function, liver and ileum histology, intestinal cytokines, intestinal tight junction proteins, lipopolysaccharide binding protein, apoptosis molecules, and nuclear factor erythroid-derived 2 (Nrf-2) / heme oxygenase (HO-1) molecules were assessed.
Results: The results showed that L. reuteri alleviated liver injury and intestinal inflammation induced by D-galactosamine. L. reuteri also improved the expression of intestinal tight junction proteins and maintained the integrity of the intestinal barrier by inhibiting apoptosis of intestinal epithelial cells. L reuteri induced an increase in Nrf-2 nuclear translocation and elevated induction of HO-1. L. reuteri treatment significantly enhanced the expression of phosphoinositide 3-kinase/protein kinase B (PI3 K/Akt), protein kinase C (PKC), and their phosphorylated forms but not mitogen-activated protein kinase. The nuclear factor kappa B (NF-κB) pathway was inhibited after L. reuteri treatment. Interleukin (IL)-17A produced by Th17 cells and γδT17 cells may not contribute to an improved function of the intestinal barrier in L. reuteri-treated SD rats.
Conclusions: Overall, our study indicated that L. reuteri-induced expression of intestinal tight junction proteins is mediated by the PI3 K/Akt-Nrf-2/HO-1-NF-κB and PKC-Nrf-2/HO-1-NF-κB pathways, which leads to inhibition of the apoptosis of intestinal epithelial cells, thus maintaining the integrity of the damaged intestinal barrier.
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