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Iron supplementation increases small intestine permeability in primary schoolchildren in Lusaka, Zambia
M Nchito1, H Friis, K F Michaelsen
1Department of Biological Sciences, University of Zambia, Lusaka, Zambia.
Insights
Iron supplementation in schoolchildren increased intestinal permeability, indicated by a higher lactulose:mannitol (L:M) ratio. This finding may explain why iron supplements sometimes worsen illness in children.
Area of Science:
- Gastroenterology
- Nutritional Science
- Pediatric Health
Background:
- Elevated intestinal permeability, quantified by the lactulose:mannitol (L:M) ratio, signifies small intestinal mucosal injury.
- Understanding the impact of micronutrient supplementation on gut health is crucial for child development.
Purpose of the Study:
- To assess the effect of iron and multi-micronutrient supplementation on intestinal permeability in schoolchildren.
- To investigate potential mechanisms linking iron supplementation to increased morbidity.
Main Methods:
- A subgroup of 153 schoolchildren (mean age 10.2 years) from a randomized trial had their intestinal permeability measured.
- The lactulose:mannitol (L:M) ratio was determined at 10 months' follow-up.
- Intervention groups included iron supplementation, multi-micronutrient supplementation (without iron), and placebo.
Main Results:
- Iron supplementation significantly increased the L:M ratio compared to placebo (0.29 vs. 0.21, P=0.025).
- Multi-micronutrient supplementation showed no effect on intestinal permeability.
- No interaction was observed between iron and multi-micronutrient interventions.
Conclusions:
- Medicinal iron supplementation in schoolchildren can lead to elevated intestinal permeability.
- This increased intestinal permeability may be a contributing factor to the negative effects of iron supplementation on morbidity observed in other studies.
Abstract:
Elevated intestinal permeability, measured as an increased lactulose:mannitol (L:M) ratio, indicates injury of the small intestinal mucosa. As part of a randomized iron and multi-micronutrient (without iron) supplementation trial (Nchito et al., 2004), we determined intestinal permeability in a subgroup of schoolchildren at 10 months' follow-up to assess the effect of the interventions. Among 153 children (mean age 10.2 years and 53.6% girls) iron supplementation resulted in a higher L:M ratio compared with placebo (0.29 vs. 0.21, P=0.025). There was no effect of multi-micronutrient supplementation, and no interaction between the interventions. The finding could be one of the mechanisms explaining the negative effects of medicinal iron supplementation on morbidity found in some other studies.
