Abstract

Helicobacter pylori is among the major pathogenic bacteria that cause chronic gastritis and peptic ulcer disease and is related to the development of gastric cancer. Several chemicals, including antibiotics, have been used to eradicate H. pylori; however, they do not always curb the infection. Ten representative type strains of lactic acid bacteria (LAB) were screened for antagonism toward H. pylori via inhibition of urease activity. Strains inhibiting the binding of H. pylori to human gastric cell line cells and suppressing H. pylori-induced interleukin-8 (IL-8) production were also screened. Of these, Pediococcus pentosaseus (SL4), which inhibited the adhesion of H. pylori to MKN-45 gastric cancer cells, Bifidobacterium longum (BG7), with urease inhibiting activity, and Lactococcus lactis (SL3), and Enterococcus faecalis (SL5), which suppressed H. pylori-induced IL-8 production within MKN-45 and AGS cells, were selected. In mouse model, these LAB stains in combination significantly suppressed IL-8 levels in serum. Gastric pH also recovered to normal values after the administration of these LAB. These stains effectively suppressed H. pylori viability, although not to the extent of antibiotic treatment. When used as probiotics, LAB may help decrease the occurrence of gastritis and reduce the risk of H. pylori infection without, inducing side effects.

• Keywords: lactic acid bacteria; Helicobacter pylori; urease activity; gastric pH; IL-8