Prebiotic Galacto-Oligosaccharides and Fructo-Oligosaccharides, but Not Acacia Gum, Increase Iron Absorption from a Single High-Dose Ferrous Fumarate Supplement in Iron-Depleted Women

by Selleckchem | Apr 20 2023

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.

Comments：

The study aimed to investigate whether prebiotic fibers, such as galacto-oligosaccharides (GOS), fructo-oligosaccharides (FOS), and acacia gum, could increase iron absorption from a higher supplemental dose of ferrous fumarate (FeFum) in iron-depleted women. Thirty women with serum ferritin (SF) levels <25 μg/L participated in a randomized, single-blind, crossover study. Each participant received a 100 mg Fe tablet labeled with either 57Fe or 58Fe, along with one of the following: 15 g GOS, 15 g FOS, 15 g acacia gum, or 6.1 g lactose and 1.5 g sucrose (control).

The primary outcome was fractional iron absorption (FIA), which was assessed by erythrocyte isotopic incorporation 14 days after administration. The study found that both GOS and FOS co-administration with FeFum significantly increased FIA (+45% and +51%, respectively) compared to the control group, resulting in an additional 10-12 mg of absorbed iron. However, acacia gum did not significantly affect FIA from FeFum.

In vitro, iron dialyzability of FeFum + GOS was 46% higher than that of FeFum alone, indicating that GOS may enhance iron solubility and availability.

Overall, the study suggests that GOS and FOS may be promising new enhancers of supplemental iron absorption, particularly in iron-depleted individuals.