Oral bacteria inhibit Helicobacter pylori growth.

Various oral bacterial species were found to inhibit the growth of Helicobacter pylori strains. The growth inhibitory activities of most of these oral bacteria were adversely affected by heating at 80 degrees C for 60 min or by protease treatment, indicating that these bacteria produce bacteriocin-like inhibitory proteins against H. pylori strains. The antagonistic effects of oral bacteria against H. pylori may restrain colonization by this organism in the oral cavity.