Lactic acid-mediated suppression of Helicobacter pylori by the oral administration of Lactobacillus salivarius as a probiotic in a gnotobiotic murine model

We examined whether or not the lactobacilli administered to treat Helicobacter pylori (H. pylori) infection can suppress the colonization of H. pylori, and we also sought to elucidate the mechanism of such suppression.We used an in vitro culture system and an H. pylori-infected gnotobiotic murine model.Among the lactobacillus species examined in vitro, Lactobacillus salivarius (L. salivarius) but not L. casei or L. acidophilus proved to be capable of producing a high amount of lactic acid and thus completely inhibiting the growth of H. pylori in a mixed culture. The validity of L. salivarius as a probiotic to suppress H. pylori and thus reduce the inflammatory response was again confirmed in vivo by using an H. pylori-infected gnotobiotic murine model.Based on our findings, L. salivarius was found to be a potentially effective probiotic against H. pylori.