Bifidobacterium Animals A6 Ameliorates Intestinal Mucosal Injury Of Mice And Study On Its Mechanism

Intestinal is the main place to absorb nutrients and it also has barrier function. The complete intestinal barrier function should include the intestinal mucosal epithelial barrier, intestinal immune system, intestinal flora and intestinal endocrine. Among them the intestinal mucosal epithelial barrier is the most important. The damaged intestinal mucosa layer increased the permeability of intestinal and led to the loss of immunity and intestinal flora disorder. The damaged mucosa may cause intestinal inflammatory diseases and reduce the production performance of livestock and poultry and even death. Bifidobacterium act as a typical probiotics, not only able to regulate the intestinal flora of livestock and poultry to inhibit the breeding of harmful bacteria, but also has effect on the prevention of diarrhea, enhance immunity and other aspects.The aim of this study was to investigate the preventing and alleviating effect of Bifidobacterium animalis A6 (BAA6) in intestinal mucosa injury through a mouse ulcerative colitis (UC) model. Then the reaearch clarify the effect of BAA6 that balance intestinal mucosal immune system, regulation of intestinal flora and the expression of tight junction protein. Finally, the mechanism of probiotics improve the intestinal mucosa damage was illuminated from the molecular level.The colitis BALB/c mice was established act as the experimental model and divided them into control, model, dextran sulfate sodium (DSS)+1 × 1010 cfu/ml BAA6, DSS+1 × 108 cfu/ml BAA6 and DSS+1 X 106 cfu/ml BAA6 groups. The results showed that the model mice has more seriousinjury of colon intestinal mucosal epithelial. The mice oral BAA6 showed an alleviation of colon shortening, disease activity index (DAI) score and myeloperoxidase (MPO) activity of colitis mice significantly (P< 0.05). And the BAA6 improved the symptoms of UC on balance Th1/ Th2 cells and restore the intestinal flora, the expression of Claudin-2, STAT6, GATA4 and Cdx2 were reduced significantly compared with model group (P< 0.05).The experiment suggest that oral an appropriate dose of BAA6 is a potential therapy for treating intestinal mucosa damage, and the mechanism of this function is to balance the Th1/Th2 cells, restore the intestinal flora and improve intestinal epithelial barrier function through down-regulation of Claudin-2 associated with the suppression of IL-13 induced STAT6 pathway and activated GATA4 and Cdx2.