The Study Of Protective Effect Of Lactobacillus Plantarum On Escherichia Coli-Induced Damage In IPEC-J2 Cells

Lactic acid bacteria can improve intestine health and ameliorate Escherichia coli-induced post-weaning diarrhea in piglets by exerting its good function as an important kind of probiotics,but the specific mechanism remains researching.The aim of this study was to investigate the effect of adhesion,survival and immunity response of lactobacillus plantarum(L.plantarum)on IPEC-J2 cells when there were pathogenic bacteria,such as Escherichia coli.In EXP.1,The adhesion of L.plantarum and inhibition of adhesion of Escherichia coli to IPEC-J2 cells were investigated;In EXP.2,Evaluating the effect of L.plantarum on ameliorating Escherichia coli-induced morphological disruption and death of IPEC-J2 cells;In EXP.3,The effect of L.plantarum on immunity response of Escherichia coli-induced IPEC-J2 cells was researched.The results showed:EXP.1,the effects of L.plantarum inhibited the adhesion of Escherichia coli to IPEC-J2 cells.107,108 and 109 CFU/m L of L.plantarum could adhere to the IPEC-J2 cells and inhibite the Escherichia coli adhesion on IPEC-J2 cells by competitive,exclusion and displacement in a dose-dependent manner.The inhibition rate to Escherichia coli of different concentrations of L.plantarum were all characterized by the higher number of living bacterium,the more obvious inhibitory effect(P<0.05).The overall trend of inhibition effect,the competitive and displacement effect was superior to exclusion effect of L.plantarum inhibited Escherichia coli adhesion on IPEC-J2 cells.EXP.2,the effects of L.plantarum on Escherichia coli-induced morphological disruption and survival of IPEC-J2 cells.The morphological and surval of IPEC-J2 cells were not affected incubated with 107 and 108 CFU/m L L.plantarum after 1,2 and 3 h,but the morphological demage and death were observed in IPEC-J2 cells incubated with 109 CFU/m L L.plantarum after 2,3 h.L.plantarum could ameliorate Escherichia coli-induced disruption of cellular morphology and death.The effect of amelioration of 108 CFU/m L L.plantarum was optimal.EXP.3,the effect of L.plantarum on immunity response of Escherichia coli-induced IPEC-J2 cells.The m RNA expression of NOD1(2 h,P<0.01)and NOD2(1 h,P<0.01)incubated with L.plantarum were increased.While incubating IPEC-J2 cells with L.plantarum,the m RNA overexpression of TLR2,TLR6,NOD2 and inflammatory cytokines IL6,IL8,TNF? induced by Escherichia coli were supressed significantly(P<0.05).