Role of lactobacillus thai strains in anti-inflammatory and antagonistic activity to helicobacter pylori

Abstract

Helicobacter pylori is the causative agent of gastric-associated disease such as gastritis, peptic ulcer, and gastric cancer. To search for probiotic bacteria with the potential adjuncts in the treatment of H. pylori-associated diseases, human gastric-derived Lactobacillus spp. were tested for the two main activities, anti-inflammatory and antagonistic activity against H. pylori. For anti-inflammatory activity, Lactobacillus conditioned media (LCM) of eight isolates showed the suppressive effect to IL-8 production which was not related to inhibition of H. pylori proliferation. LCM of L. salivarius B101 (LS-B101), L. rhamnosus B103 (LR-B103), and L. plantarum XB7 (LP-XB7) had suppressive effect to IL-8 mRNA expression in H. pylori-stimulated AGS cells by contributing to the inhibition of NF-κB and with the addition of c-Jun inactivation for LP-XB7. The anti-inflammatory effect of LP-XB7 was further assessed in vivo using a H. pylori-infected Sprague-Dawley rat model. Strain LP-XB7 contributed to a delay in the detection and colonization of H. pylori in rat stomachs, attenuated gastric inflammation, and ameliorated gastric histopathology. Additionally, the administration of LP-XB7 correlated with the suppression of TNF-α and CINC-1 in sera, and suppression of CINC-1 in the gastric mucosa of H. pylori-infected rats. These results suggest that LP- XB7 produces secreted factors capable of modulating inflammation during H. pylori infection. For antagonistic activity, screening of eighty-five isolates revealed that L. salivarius B23 (LS-B23) and B37 (LS-B37) showed positive result to H. pylori reference strains by spot-overlay method. LS-B37 was chosen for further characterization due to its strongest inhibition. Secreted antagonistic substance of LS-B37 was found to be, acid-alkali tolerant, heat-stable, stable over 3 months, not related to lactic acid, and approximately 3-10 kDa. LS-B37 also inhibited the growth of clarithromycin- and metronidazole-resistant H. pylori clinical isolates. Therefore, L. plantarum (LP-XB7) and L. salivarius (LS-B37) show promise as an adjunctive therapy for treating H. pylori-associated disease.