Effects And Mechanism Of Probiotics On Intestinal Barrier Of Neonatal Mice Infected With Rotavirus Diarrhea

Objective: We observed the neonatal mice with diarrhea infected with rotavirus andtreated with probiotics; and explored the mechanism and effects of probiotics on theintestinal mucosa barrier.Methods: RV was cultured in MA104cell, and plaque test was used to detect toxicityof RV. There were eighty neonatal mice assigned randomly into three groups: control group(20), model group (30) and probiotics treated group (30). After6hours of fasting, everymouse was given KU strains RV0.2ml(2×108PFU) intragastric of the model group andprobiotics treated group and o.2ml cell culture medium of the control group.24hours later,0.1ml probiotics (Duplex butyric acid bacteria living bacteria preparation in108CFU/kg)was administered to neonatal mice of the probiotics treated group. And0.1ml saline wasintragastric in the model group and control group. At1d、2d、3d、4d、5d、6d、7d after givendrugs, about3~4neonates in each group were sacrificed for taking intestinum tenue tissueand carotid artery blood. We observed the pathological changes of intestinum tenue tissueby light and electron microscopy. And the distribution and expression of ZO-1, Occludinwas detected by immunohistochemistry. Serum TNF-α and intestinal sIgA were assayed byELISA. Extracted intestinal tissue nucleoprotein and detected NF-κB by ELISA. SPSS17.0software was used to statistical analysis.Results:1.In the control group, none of neonatal mouse was observed diarrhea. Themodel group and probiotics treated group had varying degrees of diarrhea and weight lost.The diarrhea rate in the model group increased significantly at the third day,and weight gain was slow compared with the probiotics group(P<0.05).2.The mucosa pathological changes by light and electron microscopy revealed：Themorphology of villous was normal in the control group; but the intestinal villi were in amess and the epithelial villi extensive vacuolar degeneration in the model group; theintestinal changes of the probiotics group were significantly amelioratingd compared withthe model group.3. Immunohistochemistry of intestinal tissue displays: comparing with the controlgroup, ZO-1and Occludin in model group and probiotics group decreased significantly atthe3rdday (P<0.05); Compare with model group, ZO-1and Occludin in probiotics treatedgroup increased obviously (P<0.05).4. sIgA in model and probiotics group was significantly decreased compared with thecontrol group (P<0.05).sIgA of the model group has touched the bottom at the3rdday, andthen gradual recovery. Compare with the model group.sIgA in probiotics group increasedobviously (P<0.05).5. In the control group, the value of serum TNF-α and intestinal tissue NF-κB hasbeen at a low level, but they were significantly increased in the model group and probioticstreated group(P<0.05), two days after administration elevated, and the3rdday reached apeak, and then slowly descend. TNF-α and NF-κB in the probiotics treated group increasedobviously (P<0.05).Conclusion: probiotics can improve the pathological changes of intestinal mucosa ofrotavirus diarrhea in neonatal mice, and increased expression and distribution of epithelialcell tight junction protein ZO-1and Occluding; probiotics can increase intestinal sIgAgeneration and reduce the inflammatory cytokines TNF-α and NF-κB, and thus help toprotect the intestinal mucosa barrier, promotes the recovery of the mucosa barrier.