In addition, H. pylori strains that express the cytoxin-associated gene (CagA+) are considered to further induce the inflammatory stress in the colonized gastric mucosa, compared to the CagA- H. pylori strains, leading more frequently to the development of chronic atrophic gastritis, condition directly related to elevation of gastrin levels, through reverse feedback regulation [24-26]. This evidence concerns the gene GAST and chronic atrophic gastritis.