Helicobacter pylori infection contributes to iron deficiency and iron deficiency anemia.

Helicobacter pylori infection is a well-established risk factor for the development of iron deficiency (ID) and iron deficiency anemia (IDA). Clinical evidence from large-scale meta-analyses and randomized controlled trials consistently shows that infected individuals have significantly lower iron stores. For example, a systematic review of over 15,000 subjects found that H. pylori infection more than doubles the risk of IDA (OR 2.22; 95% CI: 1.52–3.24).

Clinical and effectiveness evidence

The causal link is reinforced by interventional data showing that H. pylori eradication significantly improves iron status.

• Treatment outcomes: Meta-analyses of randomized controlled trials (RCTs) demonstrate that combining H. pylori eradication with iron supplementation results in a greater increase in hemoglobin (weighted mean difference of 4.06 g/L) and serum ferritin compared to iron therapy alone.
• Population data: In children and adolescents, the odds of developing ID are approximately 1.5 to 1.8 times higher when infected, making it a critical consideration for unexplained anemia.

Mechanistic explanations

H. pylori disrupts iron homeostasis through three primary physiological pathways:

• Impaired absorption: The infection induces chronic atrophic gastritis, which reduces gastric acid and ascorbic acid secretion. Acid is necessary to convert dietary non-heme ferric iron (Fe3+) into the more soluble ferrous state (Fe2+) for absorption.
• Hepcidin dysregulation: H. pylori triggers systemic inflammation, elevating hepcidin levels. Hepcidin causes the degradation of ferroportin, the protein responsible for exporting iron from cells, effectively trapping iron within intestinal cells and macrophages.
• Increased iron loss: The bacterium can cause erosive gastritis and peptic ulcers, leading to chronic, occult gastrointestinal bleeding. Furthermore, H. pylori actively competes with the host by sequestering iron for its own metabolic needs using high-affinity uptake systems like the FeoB transporter.

Clinical implications

Because H. pylori can cause anemia that is refractory to standard iron supplementation, international guidelines recommend screening for and eradicating the infection in patients with unexplained or persistent iron deficiency. This is particularly relevant when traditional causes, such as dietary deficiency or heavy menstrual bleeding, have been ruled out.

Bottom line

Helicobacter pylori is a confirmed contributor to iron deficiency anemia through a combination of impaired gastric absorption, hepcidin-mediated transport blocks, and chronic micro-bleeding. Eradication of the infection is a clinically validated strategy to resolve refractory iron deficiency.