Induction of mucin gene expression by lactic acid bacteria adhering to intestinal epithelial cells

点击翻译按钮获取中文摘要

Probiotics are microbial cell preparations or components of microbial cells that have a beneficial effect on the health and well-being of the host. Selected probiotics have been shown to have significant health benefits for humans, and thus several well-characterized strains are available for human use to reduce the risk of gastrointestinal infections or to treat such infections. Some Lactic acid bacteria including lactobacilli and bifidobacteria have been used as probiotics. The aim of this project is to examine whether adhesive lactobacilli and bifidobacteria have an ability to induce expression of innate immunity-relating genes such as mucin and several cytokine genes in intestinal epithelial cells. For the purpose, Caco-2 as well as HT-29 and Intestine-407 were used as human colonic cell lines.Several strains of Lactobacillus reuteri, Lactobacillus acidophilus group, Bifidobacterium longum and Bifidobacterium bifidum were found to adhere to the human colonic cell lines. Some of adhesive strains were found to induce weakly mucin gene expression, while some strains strongly induced the anti-bacterial peptide gene including β-defensin and several cytokine genes. The gene expression seems to be dependent on the adhesion ability of the bacteria tested. It was also found that the gene response against bacterial cells was different from cell lines, i.e. HT-29 cells were adequate to examine the expression of mucin gene while Caco-2 cells were adequate to examine the expression of the anti-bacterial peptide gene and cytokine genes. The strains having the ability to induce mucin and anti-bacterial peptide genes can be considered for future in vivo challenge studies in human as probiotics.