Iron is central to the aetiology of gastrointestinal disease. Specifically, the toxic effects of excess, unabsorbed "luminal" iron ingested from the diet has been shown to be important in the development of inflammatory bowel disease and intestinal cancer. A platform for therapeutic intervention is likely to involve chelation of this luminal pool of iron. As such, a range of dietary iron chelators have been tested for their iron binding capacity. Natural biopolymers extracted from seaweed (alginates) and a variety of natural polyphenolic compounds were stratified in terms of their iron binding potential. One alginate, Manucol LD, was unique in its iron binding and demonstrated luminal iron chelation properties. With respect to the polyphenols, only one of the tested compounds (quercetin) displayed iron chelation activity in vitro and was able to suppress cellular concentrations of reactive oxygen species acting as an antioxidant. As such, it has been demonstrated that a unique alginate, Manucol LD, is an excellent candidate for sequestering luminal iron present in the gastrointestinal tract. These results underpin the rationale in utilising these types of natural and safe bio-polymers for the prevention and treatment of gastrointestinal disease.