Combined probiotic bacteria promotes intestinal epithelial barrier function in interleukin-10-gene-deficient mice

AIM:To investigate the protective effects of combinations of probiotic (Bifico) on interleukin (IL )-10 -genedeficient (IL-10 KO) mice and Caco-2 cell monolayers.METHODS: IL-10 KO mice were used to assess the benefits of Bifico in vivo .IL-10 KO and control mice received approximately 1.5 × 10 8 cfu/d of Bifico for 4 wk.Colons were then removed and analyzed for epithelial barrier function by Ussing Chamber, while an ELISA was used to evaluate proinflammatory cytokines.The colon epithelial cell line, Caco-2, was used to test the benefit of Bifico in vitro .Enteroinvasive Escherichia coli (EIEC) and the probiotic mixture Bifico, or single probiotic strains, were applied to cultured Caco-2 monolayers.Barrier function was determined by measuring transepithelial electrical resistance and tight junction protein expression. RESULTS:Treatment of IL-10 KO mice with Bifico partially restored body weight, colon length, and epithelial barrier integrity to wild-type levels.In addition, IL-10 KO mice receiving Bifico treatment had reduced mucosal secretion of tumor necrosis factor-α and interferon-γ, and attenuated colonic disease.Moreover, treatment of Caco-2 monolayers with Bifico or singlestrain probiotics in vitro inhibited EIEC invasion and reduced the secretion of proinflammatory cytokines. CONCLUSION:Bifico reduced colon inflammation in IL-10 KO mice, and promoted and improved epithelialbarrier function, enhanced resistance to EIEC invasion, and decreased proinflammatory cytokine secretion.