Iron2026-08

Gut microbiota and iron deficiency anemia: Mechanisms, microbial signatures, and dietary interactions (A narrative review).

Fayasari Adhila, Ratnayani, Nilansari Anis Febri, Pambudi Brevi Istu — Asia Pacific journal of clinical nutrition

Summary

This review explores the complex relationship between our gut bacteria and iron deficiency anemia. It suggests that an imbalance in gut microbes might not just be a result of low iron, but could actually make it harder for the body to absorb iron. Understanding this connection could lead to new ways to help manage iron deficiency.

AI-generated summary — read the original

Key points

An imbalance in gut bacteria, called dysbiosis, may contribute to iron deficiency anemia.
People with iron deficiency often have less diverse gut microbes and more bacteria that compete for iron.
While iron supplements are crucial, future treatments might also consider targeting gut health.
More research is needed to confirm direct cause-and-effect in humans regarding gut bacteria and iron absorption.

What the study looked at

What question did the study ask? This narrative review investigated how the community of bacteria in our gut, known as the gut microbiota, interacts with iron deficiency anemia (IDA). Specifically, it explored whether an imbalance in these microbes might hinder iron absorption and contribute to IDA, rather than simply being a consequence of low iron levels. How was it studied? Researchers conducted a comprehensive review of existing scientific literature from 2005 to 2026, searching databases like PubMed. They selectively gathered and analyzed various human, experimental, and mechanistic studies to synthesize the current understanding of the complex relationship between gut bacteria and iron metabolism in IDA. What did it find? The review found a complex, two-way relationship between gut bacteria and IDA. People with IDA often show reduced diversity in their gut microbes, fewer beneficial bacteria that produce short-chain fatty acids, and an increase in bacteria that compete for iron. While direct proof of cause-and-effect in humans is still limited, the findings suggest that gut health plays a significant role in how our bodies manage iron.

Dietary takeaway

This review highlights that maintaining a healthy gut microbiome might be an important, though not yet fully understood, aspect of managing iron levels. While iron-rich foods and supplements remain the primary strategy for addressing iron deficiency, future dietary advice might also consider foods that support a diverse and balanced gut flora. Remember, this is a review of existing studies, and more direct research is needed before making definitive changes to current medical guidelines.

Abstract

BACKGROUND AND OBJECTIVES: Iron deficiency anemia (IDA) is one of the most prevalent micronutrient disorders worldwide. Recent work suggests that dysbiosis may not simply be a consequence of low iron status but may actively contribute to impaired absorption. This narrative review synthesizes the evidence on gut microbiota patterns in IDA across age groups, examines the mechanistic links between dysbiosis and iron metabolism, and identifies the potential roles of microbiota-related dietary and therapeutic strategies. METHODS AND STUDY DESIGN: This narrative review used a selective, theory-driven approach, based on targeted searches of PubMed, Scopus, and Web of Science (2005-2026), to synthesize heterogeneous human, experimental, and mechanistic evidence on gut microbiota-iron interactions in iron deficiency anemia (IDA). RESULTS: Evidence suggests a bidirectional, context-dependent relationship between IDA and gut microbiota involving host iron regulation, microbial competition, metabolites, and diet. Individuals with IDA often show reduced microbial diversity, depletion of SCFA-producing taxa, and enrichment of iron-scavenging bacteria, although direct causal evidence in humans remains limited. CONCLUSIONS: IDA is commonly associated with recurring dysbiosis patterns characterized by reduced short-chain fatty acid-producing commensals and relative enrichment of inflammatory, iron-competitive taxa. While iron supplementation remains the cornerstone of evidence-based IDA management, the ecological effects of unabsorbed luminal iron on gut microbial communities support the concept of a potential "iron paradox," particularly in inflammatory or high-infection settings. Therefore, microbiota-targeted strategies should currently be regarded as hypothesis-generating concepts rather than established clinical interventions and require further mechanism and clinical validation.

View on PubMed →DOI: 10.6133/apjcn.202608_35(4).0004