Competitive exclusion of diarrheagenic Escherichia coli (ETEC) from human enterocyte‐like Caco‐2 cells by heat‐killed Lactobacillus

Diarrheagenic Escherichia coli (ETEC) bearing CFA/I or CFA/II adhesive factors specifically adhere onto the brush border of the polarized epithelial human intestinal Caco‐2 cells in culture. Heat‐killed Lactobacillus acidophilus strain LB, that adheres onto Caco‐2 cells, inhibits diarrheagenic Escherichia coli adhesion in a concentration‐dependent manner. Since the L. acidophilus does not express ETEC‐CFA adhesive factors, it can be postulated that the heat‐killed L. acidophilus LB cells inhibit diarrheagenic E. coli attachment by steric hindrance of the human enterocytic ETEC receptors.