CLDN1 and infection: This study was to investigate the effect of L. plantarum on the changes of Caco-2 cells responding to Enteroinvasive Escherichia coli (EIEC), the permeability of cell monolayer and the transmissivity of dextran, and the distribution and expression of the tight junction (TJ) proteins, such as Claudin-1, Occludin, JAM-1 and ZO-1 were examined when infected with EIEC or adhesived of L. plantarum after infection by confocal laser scanning microscopy (CLSM), immunohistochemistry and Western blotting, the cytoskeleton protein F-actin were observed with FITC-phalloidin.