Oral iron exacerbates colitis and influences the intestinal microbiome
Authors: Awad Mahalhal, Jonathan M. Williams, Sophie Johnson, Nicholas Ellaby, Carrie A. Duckworth, Michael D. Burkitt, Xuan Liu, Georgina L. Hold, Barry J. Campbell, D. Mark Pritchard, Chris S. Probert
bioRxiv preprint first posted online Aug. 6, 2018.
COMMENT: In this preprint, after studying the impact of iron oral therapy in mouse models of Inflammatory Bowel Disease (IBD) the authors suggest that oral iron therapy might have an adverse effect on the microbiome in IBD patients.
Inflammatory bowel disease (IBD) patients have chronic inflammation of the gastrointestinal tract associated with intestinal ulceration in ulcerative colitis (UC) and Crohn’s disease (CD). Iron deficiency anaemia occurs in one-third of patients and hence many of them are treated with iron oral therapies.
In this study the impact in the microbiome of the oral iron (using drugs or even only iron-rich diets) was analyzed using mice with acute colitis induced by dextran sulfate sodium (DSS). As result of this study the authors conclude that iron intake is associated with increased weight loss and more severe colitis following the induction colitis with DSS.
The authors conclude that these results are important for the advance of the knowledge about the IBD pathogenetic factors and treatment:
This is the first study to use models of colitis to contemporaneously assess the influence of dietary iron content on both disease activity and the microbiome. It emphasises the detrimental effects of both halving and doubling the amount of iron in the diet on a murine model of IBD. The diet with double the standard level of iron (400 ppm) led to key changes in the microbiome and this would imply that these changes observed were not simply driven by the severity of inflammation, but rather that lumenal free iron can also contribute to the complex interaction of factors that lead to the development of a dysbiotic state as has frequently been observed in IBD.