Abstract

• Helicobacter pylori is a gastric pathogen colonizing over half of the world population. Although colonization is frequently asymptomatic, it can lead to different clinical and pathologic consequences in humans (peptic ulcer, MALT lymphoma and gastric cancer). • An aggressive pro-inflammatory immune response is generated in the gastric tissue resulting in gastritis and a series of morphological changes that increase the susceptibility to cancer development. • Considering the difficulties shown by the traditional antimicrobial therapy, new alternatives have been searched to treat H. pylori infection and reduce the mortality and costs associated to the disease. Among these alternatives, the use of probiotics is of particular interest. Lactic acid bacteria, including the genus Lactobacillus, are among the most widely studied probiotics. • The use of immunomodulatory lactic acid bacteria (immunobiotics) has been proposed to reduce the severity of chronic inflammatory-mediated tissue damage and to improve protective immunity against H. pylori. • Searching for alternative possible treatments against H. pylori infections, the Laboratory of Bacterial Pathogenicity (University of Concepción, Chile) characterized strains isolated from stomach, including Lactobacillus fermentum UCO-979C whose probiotic properties and anti-Helicobacter pylori activity are remarkable. • We evaluated the capacity of L. fermentum UCO-979C to beneficially modulate immune. Our findings strongly support the possible immunobiotic potential of L. fermentum UCO- 979C and provide evidence of its beneficial effects against the inflammatory damage induced by H. pylori infection response of AGS cells in response to H. pylori infection.