Related Experiment Video
Updated: Jul 2, 2025
Probiotic Studies in Neonatal Mice Using Gavage
Published on: January 27, 2019
The impact of iron supplementation on the preterm neonatal gut microbiome: A pilot study
Matthew VanOrmer1, Maranda Thompson1, Melissa Thoene1
1Department of Pediatrics, University of Nebraska Medical Center, Omaha, NE, United States of America.
Insights
Routine iron supplementation in preterm infants did not significantly alter the gut microbiome composition in this study. Further research is needed to fully understand iron's impact on the infant gut microbiome.
Area of Science:
- Neonatal microbiome research
- Gastrointestinal health in premature infants
- Nutritional impacts on infant gut bacteria
Background:
- The gut microbiome is crucial for preterm infant development and health.
- Gut dysbiosis increases the risk of necrotizing enterocolitis in preterm infants.
- Iron is essential but excess iron can negatively impact the gut microbiome.
Purpose of the Study:
- To investigate the effect of routine iron supplementation on the gut microbiome of preterm infants.
- To assess potential alterations in bacterial composition following iron administration.
Main Methods:
- Stool specimens were collected from 14 preterm infants (<34 weeks gestation).
- Microbiome composition was analyzed using 16S rRNA sequencing at multiple timepoints.
- Samples were assessed before and after the initiation of iron supplementation.
Main Results:
- No significant differences in gut microbiome phyla or genera were observed after iron supplementation.
- Infant microbiome composition showed notable shifts related to the season of delivery.
- The study did not find evidence of iron-induced dysbiosis in this cohort.
Conclusions:
- Routine iron supplementation did not appear to induce significant gut dysbiosis in preterm infants in this study.
- Seasonal variations may influence the preterm infant gut microbiome.
- Larger studies are necessary to fully elucidate iron's role in the preterm gastrointestinal environment.
Objective:
The gastrointestinal microbiome in preterm infants exhibits significant influence on optimal outcomes-with dysbiosis shown to substantially increase the risk of the life-threatening necrotizing enterocolitis. Iron is a vital nutrient especially during the perinatal window of rapid hemoglobin production, tissue growth, and foundational neurodevelopment. However, excess colonic iron exhibits potent oxidation capacity and alters the gut microbiome-potentially facilitating the proliferation of pathological bacterial strains. Breastfed preterm infants routinely receive iron supplementation starting 14 days after delivery and are highly vulnerable to morbidities associated with gastrointestinal dysbiosis. Therefore, we set out to determine if routine iron supplementation alters the preterm gut microbiome.
Methods:
After IRB approval, we collected stool specimens from 14 infants born <34 weeks gestation in the first, second, and fourth week of life to assess gut microbiome composition via 16S rRNA sequencing.
Results:
We observed no significant differences in either phyla or key genera relative abundance between pre- and post-iron timepoints. We observed notable shifts in infant microbiome composition based on season of delivery.
Conclusion:
Though no obvious indication of iron-induced dysbiosis was observed in this unique study in the setting of prematurity, further investigation in a larger sample is warranted to fully understand iron's impact on the gastrointestinal milieu.
