Innovative Approaches to Study Dietary Zinc Bioavailability, Absorption and Deficiency Status.

Zinc deficiency is a common aliment predicted to affect 17 % of the world’s population. Zinc is a vital micronutrient used for over 300 enzymatic reactions and multiple biochemical and structural processes in the body. Zn inadequacy has been associated with poor growth, depressed immune function, increased vulnerability to and severity of infection, adverse outcomes of pregnancy, and neurobehavioral abnormalities. Deficiency of Zn is a major cause of early childhood morbidity and mortality. Although whole blood, plasma, and urine zinc decrease in severe zinc deficiency, accurate assessment of zinc status, especially in mild to moderate deficiency, is difficult as studies with these biomarkers are often contradictory and inconsistent. Hence, and as suggested by the World Health Organization, sensitive and specific biological markers of zinc status are still needed. In addition, although the gut is a vital organ for Zn utilization, and Zn deficiency is associated with impaired intestinal permeability and a global decrease in gastrointestinal health, alterations in the gut microbial ecology of the host under conditions of Zn deficiency have yet to be studied. In this review presentation, and by using the broiler chicken (Gallus gallus) model, we provide evidence to demonstrate that the erythrocyte linoleic acid: dihomo-γ-linolenic acid (LA:DGLA) ratio, may be a useful additional indicator for assessing zinc status more precisely. Further, we provide a characterization of distinct cecal microbiota shifts and changes in duodenal gene expression of key zinc enterocyte metabolic proteins induced by chronic dietary zinc depletion. These analyses followed long term feeding trials and were conducted in the context of biofortified staple food crops based diets, that were specifically tailored to the target zinc deficient population that consume these crops regularly.