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Updated: Mar 10, 2026
The Caco-2 Cell Bioassay for Measurement of Food Iron Bioavailability
Published on: April 28, 2022
In vitro assessment of iron availability from commercial Young Child Formulae supplemented with prebiotics
Tatiana Christides1, Julia Clark Ganis2, Paul Anthony Sharp3
1Department of Life and Sports Sciences, Faculty of Engineering and Science, University of Greenwich, Medway Campus, Chatham Maritime, Kent, ME4 4TB, UK. T.Christides@gre.ac.uk.
Insights
Iron bioavailability in young child formulae (YCF) is enhanced by ascorbic acid (AA) and prebiotics. Higher concentrations of AA and prebiotics in YCF lead to better iron absorption, crucial for preventing iron deficiency in children.
Area of Science:
- Pediatric Nutrition
- Nutritional Biochemistry
- Food Science
Background:
- Iron deficiency (ID) is a major public health concern in young children.
- Young Child Formulae (YCF) fortified with iron and ascorbic acid (AA) are potential sources to combat ID.
- Prebiotics are suggested to further enhance iron bioavailability in fortified foods.
Purpose of the Study:
- To assess the impact of varying concentrations of prebiotics and AA on iron bioavailability in YCF.
- To determine if higher levels of prebiotics and AA correlate with improved iron bioavailability.
Main Methods:
- An in vitro digestion model using Caco-2 cells was employed.
- Iron bioavailability was measured using Caco-2 cell ferritin formation as a biomarker.
- Four commercial YCF with similar iron content but different AA and prebiotic levels were analyzed.
Main Results:
- YCF with the highest concentrations of prebiotics and AA demonstrated the greatest iron bioavailability.
- Conversely, YCF with the lowest levels of prebiotics and AA showed the lowest iron bioavailability.
- Supplementation with exogenous prebiotics to equalize amounts eliminated significant differences in iron bioavailability between YCF.
Conclusions:
- Ascorbic acid and prebiotics significantly improve iron bioavailability in YCF.
- Optimizing AA and prebiotic content in YCF can enhance nutritional benefits for preventing ID in young children.
- Further in vivo studies are recommended to validate these findings.
Purpose:
Iron is essential for development and growth in young children; unfortunately, iron deficiency (ID) is a significant public health problem in this population. Young Child Formulae (YCF), milk-derived products fortified with iron and ascorbic acid (AA, an enhancer of iron absorption) may be good sources of iron to help prevent ID. Furthermore, some YCF are supplemented with prebiotics, non-digestible carbohydrates suggested to enhance iron bioavailability. The aim of our study was to evaluate iron bioavailability of YCF relative to prebiotic and AA concentrations. We hypothesised that YCF with the highest levels of prebiotics and AA would have the most bioavailable iron.
Methods:
We used the in vitro digestion/Caco-2 cell model to measure iron bioavailability from 4 commercially available YCF with approximately equal amounts of iron, but varying amounts of: AA and the prebiotics fructo- and galacto-oligosaccharides. Caco-2 cell ferritin formation was used as a surrogate marker for iron bioavailability.
Results:
The YCF with the highest concentration of prebiotics and AA had the highest iron bioavailability; conversely, the YCF with the lowest concentration of prebiotics and AA had the lowest. After the addition of exogenous prebiotics, so that all tested YCF had equivalent amounts, there was no longer a significant difference between YCF iron bioavailability.
Conclusion:
Our results suggest that ascorbic acid and prebiotics in YCF improve iron bioavailability. Ensuring that iron is delivered in a bioavailable form would improve the nutritional benefits of YCF in relation to ID/IDA amongst young children; therefore, further exploration of our findings in vivo is warranted.
