Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

BACKGROUND: Prebiotic galacto-oligosaccharides (GOS) increase iron absorption from fortification-level iron doses given as ferrous fumarate (FeFum) in women and children. Whether GOS or other fibers, such as prebiotic fructo-oligosaccharides (FOS) and acacia gum, increase iron absorption from higher supplemental doses of FeFum is unclear. OBJECTIVES: In iron-depleted [serum ferritin (SF) <25 μg/L] women, we tested if oral coadministration of 15 g GOS, FOS, or acacia gum increased iron absorption from a 100 mg Fe supplement given as FeFum. METHODS: In a randomized, single-blind, crossover study, 30 women (median age: 26.2 y; median SF: 12.9 μg/L) consumed a 100 mg Fe tablet labeled with 4 mg 57Fe or 58Fe, given with either 1) 15 g GOS; 2) 15 g FOS; 3) 15 g acacia gum; or 4) 6.1 g lactose and 1.5 g sucrose (control; matching the amounts of sucrose and lactose present in the GOS powder providing 15 g GOS), dissolved in water. The primary outcome, fractional iron absorption (FIA), was assessed by erythrocyte isotopic incorporation 14 d after administration. Data were analyzed using a linear mixed-effect model. We also tested, in vitro, iron solubility at different pH and dialyzability from the different supplement combinations administered in vivo. RESULTS: FIA from FeFum given with GOS and FOS was significantly higher (+45% and +51%, respectively; P < 0.001 for both) than control; median [IQR] total iron absorption was 34.6 mg [28.4-49.1 mg], 36.1 mg [29.0-46.2 mg], and 23.9 mg [20.5-34.0 mg], respectively. Acacia gum did not significantly affect FIA from FeFum (P = 0.688). In vitro, iron dialyzability of FeFum + GOS was 46% higher than that of FeFum alone (P = 0.003). CONCLUSIONS: In iron-depleted women, both GOS and FOS coadministration with FeFum increased iron absorption by ∼50% from a 100 mg oral iron dose, resulting in an additional 10-12 mg of absorbed iron. Thus, GOS and FOS may be promising new enhancers of supplemental iron absorption. This trial was registered at clinicaltrials.gov as NCT04194255.

Original publication

DOI

10.1093/jn/nxac003

Type

Journal article

Journal

J Nutr

Publication Date

04/2022

Volume

152

Pages

1015 - 1021

Keywords

acacia gum, ferrous fumarate, fructo-oligosaccharides, galacto-oligosaccharides, iron absorption, prebiotic, stable isotope, women, Child, Humans, Female, Adult, Iron, Prebiotics, Cross-Over Studies, Lactose, Single-Blind Method, Oligosaccharides