The Linoleic Acid: Dihomo-γ-Linolenic Acid Ratio (LA: DGLA)- an Emerging Biomarker of Zinc Status

Abstract

Abstract Objectives Assessment of erythrocyte linoleic: dihomo-γ-linolenic acid (LA: DGLA) ratio as a biomarker of Zn status, and structure and function of cecal microbiota following the consumption of a Zn-biofortified wheat diet. Methods The efficacy of the LA: DGLA ratio to predict the Zn status of subjects consuming a wheat-based diet, a representative diet of the target Zn-deficient populations, was evaluated in-vivo (Gallus gallus). Two groups (n = 15) were fed two different diets, a “high-Zn” diet (46.5 ppm Zn) and a “low-Zn” diet (32.8 ppm Zn), for 6 weeks. Dietary Zn-intake, body-weight, serum zinc, intestinal microbiome, expression of zinc related proteins, and the erythrocyte fatty acid profile were assessed (LA: DGLA ratio). Results Serum and tissues Zn concentrations were greater in the high-Zn group (P < 0.05). Duodenal expression of Zn transporters demonstrated a higher mean value in the tissues collected from the birds fed a low-Zn diet (n = 15, P < 0.05). Hepatic ∆6-desaturase expression showed a higher mean value in birds fed high-Zn diets (P < 0.05). LA: DGLA ratio was higher (P < 0.05) in the low-Zn group of birds at all-time points. Even though both groups of birds were fed Zn-deficient diets, with only 14 ppm differential in dietary Zn content, still the LA: DGLA ratio differentiated clearly between the groups, which demonstrates the sensitivity of the biomarker to change in accordance with dietary Zn intake. Conclusions Recent evidence demonstrate the potential of the LA: DGLA ratio to be used as an additional biomarker of Zn status in humans. To date, research shows that the LA: DGLA ratio corresponds to dietary Zn manipulations, both in animal model and humans. Funding Sources N/A.