Low vs High Dose Iron: Microbiome Impact Oral iron therapy , though widely prescribed for iron deficiency, is frequently associated with gastrointestinal intolerance and potential microbiome disruption. In this randomized open-label study of 30 iron-deficient non-anemic women , participants received either low-dose iron (12 mg/day) or standard-dose iron (100 mg/day) for four weeks. While alpha diversity remained unchanged, significant dose-dependent alterations in gut microbiome composition were observed, with unfavorable taxa increases in the high-dose group. Importantly, gastrointestinal adverse events were dramatically higher with standard-dose therapy (87% vs.
7%, p<0.0001). Specific microbial shifts included increased Colidextribacter and GCA-900066575 with high-dose iron, whereas beneficial taxa like Oscillospira showed opposite trends. These findings highlight that lower iron…
