Is iron supplementation likely to impair linear growth and gut microbiota composition of Myanmar young children when complementary feeding is not optimized? A randomized controlled trial.

Lwin Mar Hlaing, Min Kyaw Htet, Rosalind Gibson, Budi Utomo, Agus Firmansyah, Umi Fahmida

Journal: Philosophical transactions of the Royal Society of London. Series B, Biological sciences 2026;381(1950):

PMID: 42132028

Full Text on Silverchair Information Systems View on PubMed

Abstract

Iron deficiency, with or without anemia, remains a major public health concern among young children in Myanmar. While iron supplementation is widely recommended, its potential adverse effects on growth and gut microbiota warrant investigation, particularly in contexts of poor complementary feeding. To assess the effects of iron supplementation, with or without complementary feeding recommendations (CFRs), on micronutrient status, linear growth and gut microbiota composition among Myanmar children aged 12-23 months, a 24-week randomized controlled trial was conducted in Ayeyarwady Region of Myanmar. Fourteen clusters (villages/wards) were randomized to receive CFRs or not, and children within the clusters were randomized to receive daily aqueous iron or placebo, creating four arms: Placebo (n = 104), CFR (n = 112), Fe (n = 105) and CFRFe (n = 112) totalling 433 children. All intervention groups (CFR, Fe, CFRFe) improved haemoglobin and reduced anaemia risk compared with Placebo (AOR = 0.31 (0.15-0.62), 0.15 (0.07-0.32), 0.14 (0.07-0.31), respectively). CFR and CFRFe also improved zinc status. However, iron-alone (Fe) increased the stunting risk (AOR= 2.74 (1.04-7.23)), while CFRFe did not. No significant effects were observed on gut microbiota composition. Aqueous iron supplementation may impair linear growth when diets are not optimized; combining supplements with optimized complementary feeding may support healthier outcomes. This article is part of the theme issue 'Biological, biomedical and environmental drivers of stunting'.

Address: National Nutrition Centre, Department of Public Health, Ministry of Health and Sports, Naypyidaw100604, Myanmar.; Southeast Asian Ministers of Education Organization Regional Centre for Food and Nutrition (SEAMEO RECFON) - Pusat Kajian Gizi Regional (PKGR), Universitas Indonesia, Jakarta10430, Indonesia.; Sydney School of Public Health, The University of Sydney, Sydney, New South Wales2006, Australia.; Kai Ming Head Start Inc. , San Francisco, CA94103, USA.; Southeast Asian Ministers of Education Organization Regional Centre for Food and Nutrition (SEAMEO RECFON) - Pusat Kajian Gizi Regional (PKGR), Universitas Indonesia, Jakarta10430, Indonesia.; Sydney School of Public Health, The University of Sydney, Sydney, New South Wales2006, Australia.; Sinergi Qalbu Fikri, Depok , Depok, Jawa Barat 16952, Indonesia.; Department of Human Nutrition, University of Otago, Dunedin9016, New Zealand.; Center for Health Research, and Department of Population and Biostatistics, Faculty of Public Health, Universitas Indonesia, Depok, West Java16424, Indonesia.; Division of Pediatric Gastro-hepatology, Department of Child Health, Faculty of Medicine, Universitas Indonesia, Jakarta10430, Indonesia.; Southeast Asian Ministers of Education Organization Regional Centre for Food and Nutrition (SEAMEO RECFON) - Pusat Kajian Gizi Regional (PKGR), Universitas Indonesia, Jakarta10430, Indonesia.; Department of Nutrition Science, Faculty of Medicine, Universitas Indonesia-Dr. Cipto Mangunkusumo General Hospital, Jakarta10430, Indonesia.

DOI: 10.1098/rstb.2025.0042

Link outs

Free resources

Medical:

https://medlineplus.gov/dietarysupplements.html

Subscription / membership required

Full Text Sources:

https://royalsocietypublishing.org/rstb/article-lo...

MeSH Terms: Humans, Gastrointestinal Microbiome, Myanmar, Infant, Dietary Supplements, Iron, Infant Nutritional Physiological Phenomena, Male, Female, Anemia, Iron-Deficiency