Asymptomatic Helicobacter Pylori Infection in Preschool Children and Young Women Does Not Predict Iron Bioavailability from Iron-Fortified Foods

Abstract

Helicobacter pylori infection is common in low-income countries. It has been associated with iron deficiency and reduced efficacy of iron supplementation. Whether H. pylori infection affects iron absorption from fortified and biofortified foods is unclear. Our objective was to assess whether asymptomatic H. pylori infection predicts dietary iron bioavailability in women and children, two main target groups of iron fortification programs. We did a pooled analysis of studies in women of reproductive age and preschool children that were conducted in Benin, Senegal and Haiti using stable iron isotope tracers to measure erythrocyte iron incorporation. We used mixed models to assess whether asymptomatic H. pylori infection predicted fractional iron absorption from ferrous sulfate, ferrous fumarate or NaFeEDTA, controlling for age, hemoglobin, iron status (serum ferritin), inflammation (C-reactive protein), and test meal. The analysis included 213 iron bioavailability measurements from 80 women and 235 measurements from 90 children; 51.3% of women and 54.4% of children were seropositive for H. pylori. In both women and children, hemoglobin (Hb), serum ferritin (SF), and C-reactive protein (CRP) did not differ between the seropositive and seronegative groups. Geometric mean (95% CI) fractional iron absorption (%), adjusted for SF, was 8.97% (7.64, 10.54) and 6.06% (4.80, 7.67) in H. pylori positive and negative women (p = 0.274), and 9.02% (7.68, 10.59) and 7.44% (6.01, 9.20) in H. pylori positive and negative children (p = 0.479). Our data suggest asymptomatic H. pylori infection does not predict fractional iron absorption from iron fortificants given to preschool children or young women in low-income settings.

Keywords: H. pylori; Helicobacter pylori; asymptomatic H. pylori infection; biofortification; fortification; iron absorption; iron bioavailability; preschool children; women of reproductive age.

Figure 1

Study flow chart: Five iron absorption studies in preschool children and four iron absorption studies in women of reproductive age were conducted at different sites. Five participants were excluded from the analysis because Helicobacter pylori status was not assessed.

Figure 2

Log fractional iron absorption adjusted for SF of 40 µg/L, of H. Pylori positive and negative children (n = 90) and women (n = 80), each dot represents a test meal. H. Pylori positive children: n = 128, negative: n = 107, women n = 126 and n = 87 respectively. The line indicates the mean and 95% CI. There were no significant differences (NSD) between H. Pylori positive versus negative women nor children, assessed by LMM (dependent variable: Fractional iron absorption adjusted for serum ferritin; fixed factors: H. Pylori infection, iron compound, test meal food matrix and iron absorption enhancer or inhibitor; random factor: Subject ID number).