Probiotics inhibit enteropathogenic E-coli adherence in vitro by inducing intestinal mucin gene expression

Probiotic agents, live microorganisms with beneficial effects for the host, may offer an alternative to conventional antimicrobials in the treatment a nd prevention of enteric infections. The probiotic agents Lactobacillus pla ntarum 299v and Lactobacillus rhamnosus GG quantitatively inhibited the adh erence of an attacking and effacing pathogenic Escherichia coli to HT-29 in testinal epithelial cells but did not inhibit adherence to nonintestinal HE p-2 cells. HT-29 cells were grown under conditions that induced high levels of either MUC2 or MUC3 mRNA, but HEp-2 cells expressed only minimal levels of MUC2 and no MUC3 mRNA. Media enriched for MUC2 and MUC3 mucin were adde d exogenously to binding assays and were shown to be capable of inhibiting enteropathogen adherence to HEp-2 cells. Incubation of L. plantarum 299v wi th HT-29 cells increased MUC2 and MUC3 mRNA expression levels. From these i n vitro studies, we propose the hypothesis that the ability of probiotic ag ents to inhibit adherence of attaching and effacing organisms to intestinal epithelial cells is mediated through their ability to increase expression of MUC2 and MUC3 intestinal mucins.