Summary: | Probiotics protect the intestinal epithelium. Whether their protection against Salmonella is mediated via stabilizing the barrier integrity was examined here. The intestinal barrier integrity was assessed by measuring the trans-epithelial electrical resistance (TER) of Caco-2 cell monolayer. Cells were exposed for 1 h to Lactobacillus casei W56, Lactobacillus salivarius W24, Lactobacillus acidophilus W70, Lactococcus lactis W58, Bifidobacterium infantis W52 or Bifidobacterium bifidum W23 at 200 bacteria/cell or to Salmonella enteritidis 857 at 1–200 bacteria/cell or to a combination of either of the probiotic and Salmonella both at 200 bacteria/cell. Heat shock protein (Hsp) 70 was assessed by Western blotting. Probiotics induced a significant increase while Salmonella decreased the TER. The latter was attenuated by probiotics but without full recovery. In addition, probiotics induced over-expression of Hsp70. It may be concluded that probiotics stabilise the intestinal integrity and impede Salmonella infection via, at least in part, production of Hsp70.
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