Role of Lactobacillus in the enhancement of human intestinal epithelial barrier functions destroyed by Clostridium Difficile

Abstract

Specific strains of Lactobacillus spp. can promote intestinal integrity and prevent pathogen-induced damage of epithelial barrier function. This study aimed to find indigenous Lactobacillus Thai isolates with the ability to prevent and/or improve the integrity of epithelial tight junctions (TJs). Twenty-nine Lactobacillus isolates from infant feces, breast milk and gastric biopsies were tested for this ability by transepithelial electrical resistance (TEER) assay in Caco-2 cells. Eight Lactobacillus Thai isolates including L. fermentum L12 (LF-L12), L. oris NL49 (LO-NL49), L. murinus B57 (LM-B57), L. plantarum XB7 (LP-XB7), L. salivarius B37 (LS-B37), L. salivarius B60 (LS-B60), L. rhamnosus L34 (LR-L34) and L. casei L39 (LC-L39) prevent the destruction of TJs by C. difficile. LR- L34 which was selected for further investigation had the ability to protect and improve the intestinal epithelial barrier destroyed by C. difficile although the magnitude of improvement is lower than that of protection. Live LR-L34 had more effect than UV-treated LR-L34. Live and UV-treated LR-L34 had protection effect on the destruction of intestinal epithelial barrier by C. jejuni but not by Vibrio cholerae O1 Inaba and Salmonella Typhimurium ATCC 13311. The expression of claudin-1 significantly increased when differentiated Caco-2 cells were treated with LR-L34 alone. Furthermore, the expression of claudin-1 and occludin increased significantly when cells were pretreated with LR-L34 for 3 hours followed by the infection with C. difficile. LR-L34 is thus a probiotic strain with the ability to enhance TJs integrity, protect and improve the destruction of TJs by C. difficile.