Lactic acid bacterial extracts as anti-Helicobacter pylori: a molecular approach

Helicobacter pylori (H. pylori) infection, the main cause of chronic gastritis, increases gastric cancer risk. Antibiotics-based H. pylori eradication treatment is 90 % effective. However, it is expensive and causes side effects and antibiotic resistance. Lactic acid bacteria (LAB) could present a low-cost, large-scale alternative solution to prevent or decrease H. pylori colonization. This work aimed to study the inhibitory effects of LAB strains on the growth and pathogenic activity of H. pylori stains. To this end, we have selected the most virulent H. pylori strains (out of 20 mucosal antral biopsies) regarding cellular vacuolization and induction of apoptosis/necrosis. The selection of H. pylori pathogenic strains (clinically pre-isolated) were based on their impact of VacA activities on Hep-2 cell line, induction of apoptosis and necrosis in Caco-2 cell line. The Inhibitory effect of LAB strains on the invasion was carried out using the Caco-2 and Hela cell lines, where, they were co-cultured with the pathogenic H. pylori in the presence or absence of LAB extracts. The effect of LAB extracts on TNF-alpha secretion which induced by H. pylori-LPS was carried out by RT-qPCR. L. bulgaricus DSMZ 20080, L. acidophilus and L. plantarum (studied previously and reported as high antioxidant candidate strains) showed the highest anti-pylori activities with inhibition ranged from 51.46 to 88.19 %, they preventing the adhesion, invasion and DNA fragmentation of cell lines. In addition, they could reduce the TNF-alpha expression by 62.13 %. LAB extracts could inhibit the bacterial adhesion and invasion, gastric inflammation and DNA fragmentation induced by Helicobacter pylori.