Does Helicobacter pylori infection impair iron absorption and lower ferritin?

Helicobacter pylori (H. pylori) infection is a well-established cause of impaired iron status, contributing significantly to iron deficiency and reduced ferritin levels across diverse populations.

Clinical evidence

Extensive systematic reviews and meta-analyses provide robust evidence of the association between H. pylori and iron depletion.

• Anemia and Deficiency Risk: Research indicates that H. pylori-infected individuals have significantly higher odds of developing iron deficiency anemia (IDA), with odds ratios (OR) ranging from 1.70 to 2.68 in pediatric populations and 1.52 for iron deficiency (ID) [comp_2].
• Impact on Ferritin: Infected individuals consistently demonstrate lower serum ferritin levels compared to those without the infection. Clinical studies show that successful eradication of the bacterium leads to significant improvements in ferritin, with increases typically ranging from 9 to 30 μg/L [comp_2]. In some clinical cases, ferritin levels have normalized completely following treatment, moving from near-depletion to healthy ranges.
• Treatment Response: The clinical significance of this link is underscored by guidelines that recommend H. pylori testing and eradication for patients with unexplained or refractory iron deficiency anemia [comp_2].

Mechanistic explanations

H. pylori impairs iron status through several distinct physiological pathways:

• Reduced Bioavailability: The infection often causes chronic atrophic gastritis, leading to hypochlorhydria (reduced stomach acid). Since gastric acid is necessary to dissolve dietary iron and reduce it to the absorbable ferrous (Fe²⁺) state, its absence directly inhibits absorption [comp_1].
• Ascorbic Acid Depletion: H. pylori significantly lowers gastric juice levels of ascorbic acid (Vitamin C), a critical facilitator that normally helps convert ferric iron into a more absorbable form [comp_1].
• Bacterial Sequestration: H. pylori is a "siderophilic" (iron-loving) bacterium. It actively competes with the host for iron, utilizing specialized transport systems like FeoB to sequester iron for its own survival and virulence [comp_1].
• Systemic Regulation: The infection can trigger an inflammatory response that increases levels of hepcidin, a hormone that regulates systemic iron availability by blocking iron export from cells into the bloodstream [comp_2].

Bottom line

H. pylori infection is a scientifically supported cause of impaired iron absorption and low ferritin. Patients with refractory iron deficiency should be evaluated for the infection, as eradication frequently leads to the restoration of iron stores and resolution of anemia.