Effect of phytase on zinc absorption from a millet-based porridge fed to young Burkinabe children

• Published in: European journal of clinical nutrition Vol. 71; no. 1; pp. 137 - 141
• Main Authors: Brnić, M, Hurrell, R F, Songré-Ouattara, L T, Diawara, B, Kalmogho-Zan, A, Tapsoba, C, Zeder, C, Wegmüller, R
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.01.2017; Nature Publishing Group
• Subjects: 101/58; 6-Phytase - administration & dosage; 692/53; 692/699/1702/295; Absorption; Absorption (Physiology); Biological Availability; Burkina Faso; Cereals; Child, Preschool; Children; Children & youth; Clinical Nutrition; Developing countries; Eating; Edible Grain - chemistry; Epidemiology; Female; Food and nutrition; Food, Fortified - analysis; Health aspects; Healthy Volunteers; Humans; Infant; Internal Medicine; Isotopic tracers; LDCs; Male; Medicine; Medicine & Public Health; Metabolic Diseases; Millet; Millets; Nutritional aspects; original-article; Pediatric research; Phosphatases; Physiological aspects; Porridge; Public Health; Trace Elements - pharmacokinetics; Zinc; Zinc - pharmacokinetics; Zinc in the body; Switzerland
• ISSN: 0954-3007; 1476-5640
• DOI: 10.1038/ejcn.2016.199

Background/Objectives: Fortifying cereal staples with zinc is a strategy for increasing zinc intake in young children in developing countries. However, phytic acid (PA) naturally present in cereals strongly decreases zinc absorption. A stable-isotope zinc absorption study was conducted in young children to investigate the ability of the PA-degrading enzyme phytase to improve zinc absorption, when added to a cereal porridge immediately before consumption. Subjects/Methods: Fractional absorption of zinc (FAZ) was estimated in 35 young healthy Burkinabe children using the double-isotopic tracer ratio method with 67 Zn as oral tracer and 70 Zn as intravenous tracer, in a crossover design. The test meals were: (a) a millet-based porridge containing 1.4 mg total zinc (native plus 1 mg added as ZnSO 4 ) with a PA:Zn molar ratio of 7.7; (b) the same porridge with the enzyme phytase (20.5 phytase units (FTU)) added immediately before consumption. The exchangeable zinc pool (EZP) was determined as a potential measure of long-term zinc intake in 20 of the 35 children and compared with FAZ. Results: Mean FAZ increased from 9.5±3.4 to 16.0±5.1% ( P <0.0001), when phytase was added to the meal. The mean EZP was 3.6±0.5 mg/kg. There was no correlation between the EZP and FAZ values for either of the two test meals. Conclusions: Adding phytase immediately prior to consumption of a zinc-fortified cereal-based complementary food can improve zinc absorption in young children.