The gastric body will be photographically recorded, including images of normal mucosa or gastric mucosal changes. Finally biopsies will be taken in both groups, using a regular biopsy forceps; randomly biopsies following the Sydney protocol (two from the gastric body, two from the antrum and one from the incisura angularis) and targeted biopsies from areas with a type 2,3 or 4 pattern, to correlate them with the histological changes in H. pylori gastritis and gastric atrophy. The diagnosis of positive H. pylori infection will be done to all participants by direct visualization at histological examination and using a stool antigen test for H pylori.