Light micrograph section through a human intestinal tissue showing chronic atrophic gastritis. Atrophic gastritis is a histopathological entity characterised by chronic inflammation of the gastric mucosa with loss of the gastric glandular cells and replacement by intestinal-type epithelium, pyloric-type glands and fibrous tissue. It can be caused by persistent infection with helicobacter pylori, or can be autoimmune in origin. If a person has had chronic gastritis for a long time, some damage to the inner stomach lining may be permanent.