Gut Microbiome Alterations following Postnatal Iron Supplementation Depend on Iron Form and Persist into AdulthoodOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
Researchers gave Sprague-Dawley rat pups oral ferrous sulfate, ferrous bis-glycinate chelate, or a vehicle control from postnatal day 2 to 14. They tracked gut microbiome composition and metabolome changes, and followed a second cohort supplemented through weaning into young adulthood.
How was it studied?
Pups received one of the three postnatal treatments and were profiled for microbiome alpha-diversity and metabolites including short-chain fatty acids and trimethylamine. A separate cohort was supplemented until postnatal day 21, weaned onto standard chow, then re-assessed at about 8 weeks of age.
What did they find?
Iron supplementation reduced alpha-diversity and altered SCFA and trimethylamine levels in a form-dependent way. Lactobacilli abundance dropped 10,000-fold with iron exposure in both pre-weanling and young adult animals. In young adulthood, ferrous sulfate raised microbiome diversity above control while ferrous bis-glycinate chelate lowered it.
Why it matters
The chemical form of supplemental iron, not just the dose, shapes how the infant gut microbiome develops and recovers. Effects on Lactobacilli and diversity persisted long after supplementation ended, suggesting early iron form choices could have lasting consequences.