Clinical consequences of Helicobacter pylori infection in children and its relation with the response of the gastric mucosa to the infection

ABSTRACT

Helicobacter pylori is usually acquired during childhood and remains in the gastric mucosa for years, often lifelong if untreated. It can be concluded that the gastric mucosa of children actively responds to the presence of H. pylori. Current evidences suggest that whereas H. pylori infection rarely causes peptic ulcers or gastric atrophy in children, it seems to be associated with iron deficiency and iron deficiency anemia; the evidence also suggests the infection may cause growth retardation. In contrast, H. pylori infection has been associated with a reduced risk of asthma and allergy in children and adults; also, epidemiological studies suggest that there is an inverse association between H. pylori infection and risk for esophageal adenocarcinoma. The gastric mucosa of children elicits a significant inflammatory response in the site of infection, with increased expression of toll-like receptors (TLRs) and cytokines, and increased epithelial proliferation. This response may partly be responsible for the required "immune training" needed to protect for the development of esophageal cancer, asthma, allergy or even diabetes later in life. The response may as well be associated with growth retardation, iron deficiency and increased risk for enteric infections. It then seems that our co-evolution with H. pylori has rendered benefits for human health making clear that this relationship is complex and the decision to eradicate the infection should be taken with caution.