The impact of high-iron diet on gut microbiome and insulin sensitivity

This project investigated how excess dietary iron influences the gut microbiome and host metabolic signaling. Wild-type mice were switched from standard chow to a high-iron diet containing 2% carbonyl iron for varying durations (3 weeks or the final 3 or 7 days of a 3-week period). Fecal samples collected before and after dietary intervention were analyzed to assess microbiome composition, while liver and skeletal muscle tissues were examined for Akt phosphorylation as a marker of insulin sensitivity. High dietary iron intake caused substantial, time-dependent remodeling of the intestinal microbiome, including increased alpha and beta diversity and pronounced shifts in taxonomic abundance. Notable changes included increases in Akkermansiaceae, Rikenellaceae, Bilophila, Ruminiclostridium, and Lactobacillus, and decreases in Bifidobacteriaceae and Clostridiaceae_1. Network analyses revealed broader structural reorganization of microbial communities. These microbiome alterations coincided with reduced hepatic Akt phosphorylation after 3 weeks, suggesting impaired insulin sensitivity. Overall, the project demonstrated that short-term high-iron feeding reshapes gut microbial diversity and community structure while inducing early signs of metabolic dysfunction in the liver.