from Katsunori Kimura writing in Lactic Acid Bacteria and Bifidobacteria: Current Progress in Advanced Research:
Lactobacillus gasseri OLL2716 (LG21) was isolated from the feces of a healthy human. LG21 was selected as a probiotic against H. pylori infection by screening more than 200 Latobacillus strains by in vitro assays and animal studies. In clinical studies, the ingestion of yogurt containing LG21 decreased the number of H. pylori and IL-8 concentration in the gastric mucosa, and alleviated the mucosal inflammation in humans infected with H. pylori. LG21 was shown to be effective as a probiotic against H. pylori infection.
Further reading: Lactic Acid Bacteria and Bifidobacteria: Current Progress in Advanced Research