The chelation of colonic luminal iron by a unique sodium alginate for the improvement of gastrointestinal health

Abstract

Scope: Iron is an essential nutrient. However, in animal models, excess unabsorbed dietary iron residing within the colonic lumen has been shown to exacerbate inflammatory bowel disease and intestinal cancer. Therefore, the aims of this study were to screen a panel of alginates to identify a therapeutic that can chelate this pool of iron and thus be beneficial for intestinal health.

Methods and results: Using several in vitro intestinal models, it is evident that only one alginate (Manucol LD) of the panel tested was able to inhibit intracellular iron accumulation as assessed by iron-mediated ferritin induction, transferrin receptor expression, intracellular (59) Fe concentrations, and iron flux across a Caco-2 monolayer. Additionally, Manucol LD suppressed iron absorption in mice, which was associated with increased fecal iron levels indicating iron chelation within the gastrointestinal tract. Furthermore, the bioactivity of Manucol LD was found to be highly dependent on both its molecular weight and its unique compositional sequence.

Conclusion: Manucol LD could be useful for the chelation of this detrimental pool of unabsorbed iron and it could be fortified in foods to enhance intestinal health.

Keywords: Absorption; Alginate; Chelation; Intestinal; Iron.