Immunomodulatory effects of Lactobacillous plantarum and Helicobacter pylori CagA⁺ on the expression of selected superficial molecules on monocyte and lymphocyte and the synthesis of cytokines in whole blood culture.

Helicobacter pylori (H. pylori) infections are usually superficial and clinically asymptomatic, but in approximately 10-20% cases it can be more aggressive and associated with other pathologies. The reason for weak or strong pro-inflammatory responses in gastric mucosa that occur during H. pylori infection is not understood. Combined treatment, including antibiotic therapy with administration of probiotic bacteria along, considerably improves the effectiveness of H. pylori eradication and reduces the relapse rate. Thus, the aim of this study was to analyze the effect of Lactobacillus plantarum (L. plantarum) and/or H. pylori CagA(+) on leucocytes in whole blood cultures. This study revealed how selected strains of H. pylori and L. plantarum modulate expression of chosen membrane markers of monocytes and lymphocytes, and the cytokine synthesis of in vitro cultures. The level of IFN-γ was higher in cultures stimulated with L. plantarum than in combination of this two examinated strains. We also observe the tendency to increase the level of IFN-γ by L. planatrum in relation to cells stimulated by H. pylori. In contrast, both H. pylori alone and in combination with L. plantarum had a strong modulatory effect on the synthesis of interleukin-10. Moreover lymphocytes with higher expression of CD25 and CD58 receptors was observed only in those cultures that were stimulated with L. plantarum strain alone or in combination with H. pylori. Effects exerted on the immune system, both in terms of natural and adaptive response, constitute the only functional criterion of probiotic bacteria. The immunostimulant effects documented in this study suggest that Lactobacillus spp. can restore immune function of mucosal membrane during symptomatic infection with H. pylori.