Helicobacter pylori is a bacterium known to infect the gastric environment and has been associated with gastroduodenal diseases, including peptic ulcers and gastric adenocarcinoma. However, since the 1980s, the relationship between Helicobacter pylori infection and extragastric manifestations has been studied, such as inflammatory bowel disease, iron and B12 deficiency, non-alcoholic fatty liver disease, hepatocellular carcinoma, multiple sclerosis, Alzheimer's disease, Parkinson's disease, and Guillain-Barré syndrome.