HP and chronic gastritis: Hp is a gram-negative bacterial pathogen that selectively colonizes the gastric epithelium.93 The infection is a leading cause of gastroduodenal pathology.94 In 1994, the International Agency for Research on Cancer labeled Hp as a definite (group I) carcinogen for GC.95 Indeed, the infection is the major cause of chronic gastritis that sequentially causes precancerous modifications, namely atrophic gastritis, intestinal metaplasia, dysplasia and ultimately, GC.