The ability of prebiotics, and inulin and fructooligosaccharides (FOS) in particular, to improve absorption of minerals such as calcium and magnesium has been reported many times over the past 20 years. The mechanism of action is reportedly linked to the selective fermentation of the prebiotics to produce short chain fatty acids (SCFAs), which in turn reduce the pH and facilitate mineral absorption.
The new study, published in Molecular Nutrition & Food Research, indicated that GOS may be effective at improving iron absorption in young lab animals in a dose-dependent manner. Similar results were observed for FOS.
Scientists from Shenzhen University claim that their study is the first to report that GOS may boost iron absorption and may offer a new way to improve iron status of the millions of children around the world with insufficient or deficient iron levels.
According to the World Health Organization (WHO), about 30% of the world’s population may have low red blood cell numbers due to insufficient iron. In the US, almost 10% of toddlers have inadequate bodily stores of iron. A 2021 study from scientists at Columbia University suggests that we may be underestimating the prevalence of iron deficiency.
Study details
The researchers subjected lab rats to an iron-deficient diet for 14 days and then randomly divided them into one of five groups: All groups received a standard rat chow supplemented with 0%, 3%, 5%, 10% GOS and 10% FOS for 21 days. The GOS was provided by Bimuno and the FOS was Synergy 1 provided by Beneo.
The results showed that GOS doses over 5% improved iron status in the animals. In addition, the higher GOS doses also significantly affected the expression of iron-binding/ transport protein, said the researchers.
The researchers said that translation of the results to humans should be done with caution, noting that other studies showed that GOS’ efficacy may be related to the form of iron present in the meals. Specifically, studies using GOS and supplemental ferrous fumarate and ferric sodium EDTA (NaFeEDTA) or iron sulfate in infants or iron-depleted women yielded mixed results, mostly negative.
“Our study with ferric citrate as iron source suggested higher dose of GOS supplementation could potentially enhance iron absorption in anemic children even given iron in a less bioavailable form,” they wrote. “Future well-designed human studies are required to further explore the role of prebiotic oligosaccharides in enhancing iron absorption in anemic subjects.
“For the first time, the present study provided evidence that GOS supplementation induced a dose-response effect on iron absorption and gut microbiota in the established model, suggesting a positive role of GOS in ameliorating [iron deficiency anemia] in children,” concluded the researchers.
Source: Molecular Nutrition & Food Research
Published online, e2101064. doi: 10.1002/mnfr.202101064
“Prebiotic Oligosaccharides Enhance Iron Absorption Via Modulation of Protein Expression and Gut Microbiota in a Dose-response Manner in Iron-deficient Growing Rats”
Authors: J-H. Chen et al.