Heat-killed Lactobacillus acidophilus inhibits adhesion of Escherichia coli B41 to HeLa cells.

Escherichia coli B41 (O101: K99: F41: ST+) adheres to HeLa 229 cells in a diffuse pattern. Heat-killed (100-105 degrees C) Lactobacillus acidophilus (Lactéol strain) was found to inhibit this adhesion in a dose-dependent manner. This inhibitory action was lost after lysis of the L acidophilus, suggesting steric hindrance of E coli adhesion sites rather than competition for a common binding site. A thermostable factor (100-105 degrees C) excreted by L acidophilus into the medium may be required for the adhesion of L acidophilus to HeLa cells, and for the inhibition of adhesion of E coli to these cells.