Iron and intestinal immunity

Recent advances in the study of iron metabolism have led to a better understanding of the molecular basis for the interactions between iron and the inflammatory response. We will review this new information in the context of the gastrointestinal tract.

The effects of iron on microbial enteropathogens are well known. Recent work has demonstrated that iron also has potentially important effects on the intestinal microbiota. On the host side, hepcidin, a key regulator of mammalian iron metabolism, has emerged as an important mediator of the cross-talk between iron homeostasis and inflammation. Hepcidin-dependent changes in iron flux can influence the expression of inflammatory cytokines, and conversely, inflammatory cytokines can induce hepcidin expression and alter iron homeostasis. Hepcidin levels have been found to be elevated in some studies of inflammatory bowel disease, while manipulating hepcidin expression in animal models of this condition has beneficial effects on both inflammation and dysregulated iron metabolism.

The information on iron metabolism that has become available in recent years has shed new light on the pathogenesis of inflammatory diseases of the gastrointestinal tract, and is also starting to suggest new approaches to treating such diseases.