Consumption of galacto-oligosaccharides increases iron absorption from a micronutrient powder containing ferrous fumarate and sodium iron EDTA: a stable-isotope study in Kenyan infants.

Whether consumption of prebiotics increases iron absorption in infants is unclear. We set out to determine whether prebiotic consumption affects iron absorption from a micronutrient powder (MNP) containing a mixture of ferrous fumarate and sodium iron EDTA (FeFum+NaFeEDTA) in Kenyan infants. Infants ( = 50; aged 6-14 mo) consumed maize porridge that was fortified with an MNP containing FeFum+NaFeEDTA and 7.5 g galacto-oligosaccharides (GOSs) (Fe+GOS group, = 22) or the same MNP without GOSs (Fe group, = 28) each day for 3 wk. Then, on 2 consecutive days, we fed all infants isotopically labeled maize porridge and MNP test meals containing 5 mg Fe as FeFum+NaFeEDTA or ferrous sulfate (FeSO). Iron absorption was measured as the erythrocyte incorporation of stable isotopes. Iron markers, fecal pH, and bacterial groups were assessed at baseline and 3 wk. Comparisons within and between groups were done with the use of mixed-effects models. There was a significant group-by-compound interaction on iron absorption ( = 0.011). The median percentages of fractional iron absorption from FeFum+NaFeEDTA and from FeSO in the Fe group were 11.6% (IQR: 6.9-19.9%) and 20.3% (IQR: 14.2-25.7%), respectively, ( < 0.001) and, in the Fe+GOS group, were 18.8% (IQR: 8.3-37.5%) and 25.5% (IQR: 15.1-37.8%), respectively ( = 0.124). Between groups, iron absorption was greater from the FeFum+NaFeEDTA ( = 0.047) in the Fe+GOS group but not from the FeSO ( = 0.653). The relative iron bioavailability from FeFum+NaFeEDTA compared with FeSO was higher in the Fe+GOS group than in the Fe group (88% compared with 63%; = 0.006). There was a significant time-by-group interaction on spp. ( = 0.008) and // spp. ( = 0.018); // spp. decreased in the Fe group ( = 0.013), and there was a nonsignificant trend toward higher spp. in the Fe+GOS group ( = 0.099). At 3 wk, iron absorption was negatively correlated with fecal pH ( < 0.001) and positively correlated with // spp. ( = 0.001). GOS consumption by infants increased iron absorption by 62% from an MNP containing FeFum+NaFeEDTA, thereby possibly reflecting greater colonic iron absorption. This trial was registered at clinicaltrials.gov as NCT02666417.