Published on June 2026 | Nutrition, Public Health, Food Science, Dietetics, Gut Microbiome, Adolescent Health, Iron Deficiency Anemia

The Iron–Gut Microbiome Axis in Adolescent Girls: Global Evidence, Mechanisms, and Therapeutic Strategies to Combat Anemia

Background and Aims: Anemia remains one of the most pervasive nutritional disorders worldwide, affecting approximately 1.92 billion individuals in 2021 and contributing to nearly 52 million years lived with disability (YLDs). Among vulnerable populations, adolescent girls bear a disproportionate burden due to rapid growth, menstruation, and inadequate dietary iron intake. Emerging evidence identifies the gut microbiome as a critical regulator of iron homeostasis and absorption. Methods: This narrative review synthesizes evidence from the Global Burden of Disease Study 2021, WHO reports, systematic reviews, randomized controlled trials, and Mendelian randomization studies published between 2021 and 2025. Results: Although global anemia prevalence has declined modestly, the absolute burden continues to rise. Iron deficiency disrupts beneficial gut microbiota while promoting pathogenic organisms that impair iron absorption through inflammatory pathways involving hepcidin. Microbiome-targeted interventions and optimized alternate-day iron supplementation improve hematological outcomes. Conclusions: Adolescent anemia should be viewed as a gut–iron axis disorder rather than solely a dietary deficiency. Integrating iron supplementation with microbiome modulation offers a more effective and sustainable strategy for improving hematological health, reproductive outcomes, and long-term nutritional status.