Speaker
Description
Iron deficiency remains the most prevalent micronutrient deficiency globally, affecting over 2 billion people, driven largely by reliance on cereal staple foods that are inherently low in bioavailable Fe. Biofortification, the enhancement of a crop’s endogenous nutrient content and bioavailability, is increasingly recognized as an effective strategy to combat Fe deficiency. While much research has focused on increasing total Fe content in cereal crops, an alternative approach targets the bioavailability of Fe already present in the grain. Nicotianamine (NA), a Fe chelator ubiquitous in cereal grains, has emerged as a key target for this strategy. Our group, in collaboration with the University of Melbourne, has demonstrated that NA-biofortified wheat enhances Fe bioavailability in vitro and in vivo (Gallus gallus) models. While poorly understood, the mechanism underlying this effect is hypothesized to involve an alternative intestinal absorption pathway. It is hypothesized that NA binds Fe to form a stable NA-Fe chelate which bypasses classical Fe(II) uptake via metal transporters in the duodenum, and therefore absorbed more distally via amino acid transporters in the jejunum. Under this framework, NA mediated uptake provides a “physiological safety net” where Fe that escapes proximal absorption is readily chelated by dietary NA and absorbed further along the intestine; thereby enhancing its bioavailability. Spatially resolving the distribution of Fe across the small intestine using μXRF would provide novel and direct evidence for the relevance of this pathway, specifically allowing the investigation of whether the addition of NA to Fe(II) shifts the pattern of Fe more distally. However, the techniques and considerations required to map Fe across the entirety of an animal’s small intestine via μXRF have not been established. This preliminary study therefore aimed to develop and validate these techniques as a necessary foundation for subsequent experiments investigating the mechanistic basis of NA-enhanced Fe bioavailability.