Inhibitory effects of probiotic & gastro-intestinal bacteria on H. pylori in vitro

Introduction: Helicobacter pylori is a highly prevalent pathogen affecting approximately 50% of the world population, causing chronic gastritis and subsequently adenocarcinoma. Antibiotic resistance rates in H. pylori are increasing, thus demanding alternative treatment options. Some beneficial bacteria, including probiotics and gastrointestinal commensals, were shown to inhibit H. pylori growth, viability, and initial attachment to the gastric epithelium. Methods: In this review we systematically summarized the currently available literature for in vitro inhibition of H. pylori through beneficial bacteria from the Lactobacillales order. We performed research on PubMed and Google scholar in accordance with the PRISMA guidelines. Results: A multitude of species was shown to possess anti-H. pylori activity although the majority of investigated bacteria belonged to only one bacterial genus: Lactobacillus. Anti-H. pylori activity was mediated through transcriptional modulation of virulence factors, a competition for binding sites, an induction of a dormancy state of H. pylori and the secretion of anti-H. pylori compounds. Conclusion: Many bacterial compounds that show probiotic properties are capable of inhibiting H. pylori in in vitro experiments. However, a huge variety of test methods to detect anti-H. pylori effects demands for a standardization.