Antibacterial activity of lactobacilli probiotics on clinical strains of Helicobacter pylori

Treatment of Helicobacter pylori infection by common drugs may be associated with several problems such as antimicrobial resistance to commonly used antibiotics and side effects of employed drugs. Therefore, exploration of non-chemical compounds which are safer than chemical ones is becoming important as an alternative therapy. The purpose of this study was to evaluate the effects of lactic acid bacteria (LAB) against clinical strains of H. pylori. Study of antibacterial effects of LAB against H. pylori strains included:  evaluation of LAB effects as well as its cell-free supernatant (CFS) to reduce the number of H. pylori, and to examine the effects of CFS to inhibit the urease activity of H. pylori. The anti-adhesion effect of LAB on adherence of H. pylori to epithelial cell line was also evaluated. Evaluation of the anti H. pylori effect of LAB depended on the strain of H. pylori and Lactobacillus. However, CFS of LAB reduced significantly the growth of all H. pylori strains. Also, urease activity of H. pylori strains was inhibited by CFS of LAB demonstrating that their organic acid may have a role in this inhibition. The significant anti-adhesion effect of LAB on adherence of H. pylori was also observed. Presence of LAB and/or their CFS can reduce the count of H. pylori, inhibit the urease activity of H. pylori, and reduce adhesion of H. pylori to epithelial cell line. This may be important for the impact of H. pylori colonization in the host stomach.