Gut Microbiota as a Key Regulator of Iron Absorption: Mechanisms, Challenges, and Therapeutic Perspectives

The human gut hosts a diverse community of microorganisms that play an essential role in maintaining host health. Among various physiological processes influenced by gut microbiota, iron absorption has gained attention due to its critical importance in systemic iron homeostasis. Iron is vital for oxygen transport, enzymatic activity, and immune function, yet its dysregulation leads to widespread disorders such as iron deficiency anemia (IDA) and iron overload conditions like hemochromatosis. Mechanisms of Gut Microbiota-Mediated Iron Absorption: Gut microbiota influences iron metabolism via multiple pathways. Microbial metabolites, including short-chain fatty acids (SCFAs), enhance iron bioavailability by modulating intestinal pH and solubilizing dietary iron. Commensal bacteria compete with the host for iron through the siderophore production, direct iron uptake, and reduction of ferric to ferrous iron, thus shaping iron availability. Furthermore, hypoxia-inducible factors (HIFs) regulate iron transport proteins and maintain intestinal iron absorption under variable oxygen conditions influenced by microbiota-host interactions. Challenges in Iron Absorption Related to Gut Dysbiosis: Disruptions in gut microbial balance (dysbiosis) can impair iron absorption and contribute to systemic disease. Excessive oral iron supplementation may alter gut microbiota composition, promoting pathogenic bacteria and inflammation. Iron overload modifies microbial diversity and enhances virulence of harmful species, increasing risks for gastrointestinal diseases like Inflammatory Bowel Bisease (IBD) and colorectal cancer. Conversely, iron deficiency may reduce microbial diversity and compromise mucosal immunity, highlighting the complex bidirectional relationship between an iron status and microbiota composition. Therapeutic Potential of Microbiota-Targeted Interventions: Emerging therapies aimed at modulating the gut microbiota which hold promise for optimizing iron absorption. Probiotics (e.g., Lactobacillus, Bifidobacterium) and prebiotics improve iron uptake by enhancing beneficial microbial populations and metabolite production. Tailored dietary strategies incorporating iron absorption enhancers and microbiota-friendly fibers can synergistically combat iron deficiency. Additionally, fecal microbiota transplantation (FMT) shows potential in restoring microbial balance and improving iron status in patients with severe dysbiosis, although clinical evidence remains preliminary. Gut microbiota is a pivotal regulator of iron absorption and systemic iron homeostasis. Understanding the intricate mechanisms of microbiota-iron interactions is vital for developing novel, personalized therapeutic strategies to address iron-related disorders. Future research should mainly focus on elucidating microbiota dynamics, optimizing probiotic and dietary interventions, and conducting large-scale clinical trials to translate these findings into an effective clinical practice.