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Liria-Domínguez R, Penny M, Kroon PA, Burgos G, Dainty J, Zeder C, Zimmermann MB, King J, Mithen R, Boy E, Al-Jaiballi O, Fairweather-Tait S. Biofortified Yellow-Fleshed Potatoes Provide More Absorbable Zinc than a Commonly Consumed Variety: A Randomized Trial Using Stable Isotopes in Women in the Peruvian Highlands. J Nutr 2023; 153:2893-2900. [PMID: 37648112 PMCID: PMC10613720 DOI: 10.1016/j.tjnut.2023.08.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/16/2023] [Accepted: 08/24/2023] [Indexed: 09/01/2023] Open
Abstract
BACKGROUND Zinc-biofortified potatoes have considerable potential to reduce zinc deficiency because of their low levels of phytate, an inhibitor of zinc absorption, and their high consumption, especially in the Andean region of Peru. OBJECTIVES The purpose of this study was to measure fractional and total zinc absorption from a test meal of biofortified compared with regular potatoes. METHODS We undertook a single-blinded randomized crossover study (using 67Zn and 70Zn stable isotopes) in which 37 women consumed 500-g biofortified or regular potatoes twice a day. Urine samples were collected to determine fractional and total zinc absorption. RESULTS The zinc content of the biofortified potato and regular potato was 0.48 (standard deviation [SD]: 0.02) and 0.32 (SD: 0.03) mg/100 g fresh weight, respectively. Mean fractional zinc absorption (FZA) from the biofortified potatoes was lower than from the regular potatoes, 20.8% (SD: 5.4%) and 25.5% (SD: 7.0%), respectively (P < 0.01). However, total zinc absorbed was significantly higher (0.49; SD: 0.13 and 0.40; SD: 0.11 mg/500 g, P < 0.01, respectively). CONCLUSIONS The results of this study demonstrate that biofortified potatoes provide more absorbable zinc than regular potatoes. Zinc-biofortified potatoes could contribute toward reducing zinc deficiency in populations where potatoes are a staple food. This trial was registered at clinicaltrials.gov as NCT05154500.
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Affiliation(s)
| | - Mary Penny
- Instituto de Investigación Nutricional, Lima, Peru
| | - Paul Antony Kroon
- Food, Microbiome and Health Program, Quadram Institute Bioscience, Norwich Research Park, Norwich, United Kingdom
| | - Gabriela Burgos
- Genetics, Genomics, and Crop Improvement Division, International Potato Center, Lima, Peru
| | - Jack Dainty
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Christophe Zeder
- ETH Zürich, Laboratory of Human Nutrition, Department of Health Sciences and Technology, Institute of Food, Nutrition, and Health, Zurich, Switzerland
| | - Michael B Zimmermann
- ETH Zürich, Laboratory of Human Nutrition, Department of Health Sciences and Technology, Institute of Food, Nutrition, and Health, Zurich, Switzerland
| | - Janet King
- Department of Nutritional Sciences and Toxicology, University of California-Berkeley, Berkeley, CA, United States
| | - Richard Mithen
- Liggins Institute, Waipapa Taumata Rau - The University of Auckland, Auckland, New Zealand
| | - Erick Boy
- HarvestPlus Programme, Innovation, Policy and Scaling Unit, International Food Policy Research Institute, Washington, DC, USA
| | - Olla Al-Jaiballi
- Food, Microbiome and Health Program, Quadram Institute Bioscience, Norwich Research Park, Norwich, United Kingdom
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Wang R, Ye M, Zhu S, Zeng Q, Yuan Y. Development, characterization and in vivo zinc absorption capacity of a novel soy meal hydrolysate-zinc complexes. Front Nutr 2023; 10:1211609. [PMID: 37485380 PMCID: PMC10358849 DOI: 10.3389/fnut.2023.1211609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 06/19/2023] [Indexed: 07/25/2023] Open
Abstract
Background Zinc is an essential trace element for the human body. Recently, a novel Zn-binding peptide, Lys-Tyr-Lys-Arg-Gln-Arg-Trp (PP), was purified and identified from soy protein hydrolysates with high Zn-binding capacity (83.21 ± 2.65%) by our previous study. The preparation of soy meal hydrolysates (SMHs)-Zn complexes is convenient and low-cost, while PP (Lys-Tyr-Lys-Arg-Gln-Arg-Trp)-Zn complexes have a higher coordination rate but a relatively high cost. The aim of this study was to investigate the effect of soy meal hydrolysates (SMHs)-Zn complexes on zinc absorption in mice model, and synthetic soy peptide (PP)-Zn complexes with high Zn-binding capacity were used as control. Firstly, SMHs were prepared by enzymolysis, and the PP (Lys-Tyr-Lys-Arg-Gln-Arg-Trp) were synthesized based on previous studies. The binding mechanism of soy hydrolysates and zinc was analyzed by spectral analysis. Furthermore, the cytotoxicity of the SMHs-Zn complexes was also studied using the CCK-8 method. The effect of zinc absorption was evaluated based on Zn content, total protein and albumin content, relevant enzyme system, and the PeT1 and ZnT1 mRNA expression levels. Result The result showed that zinc was bound with carboxyl oxygen and amino nitrogen atoms on SMHs, with hydrophobic and electrostatic interactions as auxiliary stabilizing forces. SMHs-Zn were proved to have great solubility and a small particle size at different pH values, and it showed a beneficial effect on Caco-2 cells growth. Moreover, it was proved that SMHs-Zn and PP-Zn could increase the levels of zinc and the activity of Zn-related enzymes in mice. SMHs-Zn possessed higher PepT1 and ZnT1 mRNA expression levels than PP-Zn in the small intestine. Conclusion SMHs-Zn with a lower Zn-binding capacity had similar effects on zinc absorption in mice as PP-Zn, suggesting that the bioavailability of peptide-zinc complexes in mice was not completely dependent on their Zn-binding capacity, but may also be related to the amino acid composition.
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Consalez F, Ahern M, Andersen P, Kjellevold M. The Effect of the Meat Factor in Animal-Source Foods on Micronutrient Absorption: A Scoping Review. Adv Nutr 2022; 13:2305-2315. [PMID: 36055778 PMCID: PMC9776636 DOI: 10.1093/advances/nmac089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/21/2022] [Accepted: 08/18/2022] [Indexed: 01/29/2023] Open
Abstract
The EAT-Lancet Commission's planetary health guidelines suggest a reduction in the consumption of animal-source foods (ASFs) for better health and more sustainable food systems. ASFs are highly nutrient dense, therefore suited to address the widespread issue of micronutrient deficiencies, particularly in low-resource settings where diets are predominantly plant based. ASFs are also believed to contain the meat factor, a substance enhancing the absorption of micronutrients from plant-based foods. We conducted a scoping review with the objective of systematically mapping the available evidence on the meat factor. The MEDLINE/PubMed and Web of Science databases were searched for literature published up to September 2021. Articles eligible for inclusion were all studies assessing the effect of adding ASFs and/or ASF fractions on micronutrient absorption from a plant-based meal or the overall diet in animal models and human subjects. Screening and data extraction were performed, and results were charted into 12 categories. We identified 77 articles eligible for inclusion, 52 of which were conducted in human subjects, 24 in animal models, and 1 in both. The addition of muscle tissue and muscle tissue fractions to single plant-based meals steadily increased absorption of iron and zinc across studies. The efficacy of the meat factor in increasing iron and zinc absorption in the overall diet is less clear. No clear differences emerged between red meat, poultry, and fish in promoting the meat factor effect. No clear evidence indicates that milk and egg products contain the meat factor. Our review highlights the importance of muscle tissue for the potential of the meat factor to enhance absorption of micronutrients of concern. Although the literature supports including sustainable and economically accessible forms of these ASFs into the diet, we found limited studies in resource-poor countries and of diets with low meat intake.
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Affiliation(s)
- Fabio Consalez
- Fisheries and Aquaculture Division, Food and Agriculture Organization of the United Nations (FAO), Rome, Italy
| | - Molly Ahern
- Fisheries and Aquaculture Division, Food and Agriculture Organization of the United Nations (FAO), Rome, Italy
| | - Peter Andersen
- Department of Geography, University of Bergen, Bergen, Norway
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Ceballos-Rasgado M, Lowe NM, Moran VH, Clegg A, Mallard S, Harris C, Montez J, Xipsiti M. Toward revising dietary zinc recommendations for children aged 0 to 3 years: a systematic review and meta-analysis of zinc absorption, excretion, and requirements for growth. Nutr Rev 2022:6881443. [PMID: 36478064 DOI: 10.1093/nutrit/nuac098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
CONTEXT The Food and Agriculture Organization of the United Nations and the World Health Organization are updating their dietary zinc recommendations for children aged 0 to 3 years. OBJECTIVE The aim of this review was to retrieve and synthesize evidence regarding zinc needs for growth as well as zinc losses, absorption, and bioavailability from the diet. DATA SOURCES MEDLINE, Embase, and Cochrane Library databases were searched electronically from inception to August 2020. Studies assessing the above factors in healthy children aged 0 to 9 years were included, with no limits on study design or language. DATA EXTRACTION Ninety-four studies reporting on zinc content in tissue (n = 27); zinc absorption (n = 47); factors affecting zinc bioavailability (n = 30); and endogenous zinc losses via urine, feces, or integument (n = 40) met the inclusion criteria. Four reviewers extracted data and two reviewers checked for accuracy. DATA ANALYSES Studies were synthesized narratively, and meta-analyses of zinc losses and gains as well the subgroups of age, type of feeding, country's income, and molar ratio of phytate to zinc were conducted. Meta-analysis revealed an overall mean (95%CI) urinary and endogenous fecal zinc excretion of 17.48 µg/kg/d (11.80-23.15; I2 = 94%) and 0.07 mg/kg/d (0.06-0.08; I2 = 82%), respectively, with a mean fractional zinc absorption of 26.75% (23.69-29.81; I2 = 99%). Subgrouping by age revealed differences in mean values associated with the transition from milk-based diets to solid food during the first 3 years of life. CONCLUSION This review synthesizes data that may be used to formulate zinc requirements in young children. Results should be interpreted with caution because of considerable heterogeneity in the evidence. SYSTEMATIC REVIEW REGISTRATION PROSPERO registration number CRD42020215236.
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Affiliation(s)
| | - Nicola M Lowe
- Centre for Global Development, University of Central Lancashire, Preston, United Kingdom
| | - Victoria H Moran
- Centre for Global Development, University of Central Lancashire, Preston, United Kingdom
| | - Andrew Clegg
- Synthesis, Economic Evaluation and Decision Science (SEEDS) Group, Applied Health Research Hub, University of Central Lancashire, Preston, United Kingdom
| | - Simonette Mallard
- New Zealand College of Public Health Medicine, Wellington, New Zealand
| | - Catherine Harris
- Synthesis, Economic Evaluation and Decision Science (SEEDS) Group, Applied Health Research Hub, University of Central Lancashire, Preston, United Kingdom
| | - Jason Montez
- Nutrition and Food Safety Department, World Health Organization, Geneva, Switzerland
| | - Maria Xipsiti
- Food and Nutrition Division, Food and Agriculture Organization of the United Nations, Rome, Italy
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Shkembi B, Huppertz T. Influence of Dairy Products on Bioavailability of Zinc from Other Food Products: A Review of Complementarity at a Meal Level. Nutrients 2021; 13:4253. [PMID: 34959808 PMCID: PMC8705257 DOI: 10.3390/nu13124253] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 11/24/2021] [Accepted: 11/25/2021] [Indexed: 11/16/2022] Open
Abstract
In this paper, we reviewed the role of dairy products in dietary zinc absorption. Dairy products can have a reasonable contribution for dietary zinc intake in Western diets, where dairy consumption is high. However, the co-ingestion of dairy products can also improve zinc absorption from other food products. Such improvements have been observed when dairy products (e.g., milk or yoghurt) were ingested together with food such as rice, tortillas or bread products, all of which are considered to be high-phytate foods with low inherent zinc absorption. For foods low in phytate, the co-ingestion of dairy products did not improve zinc absorption. Improved zinc absorption of zinc from high-phytate foods following co-ingestion with dairy products may be related to the beneficial effects of the citrate and phosphopeptides present in dairy products. Considering that the main dietary zinc sources in areas in the world where zinc deficiency is most prevalent are typically high in phytate, the inclusion of dairy products in meals may be a viable dietary strategy to improve zinc absorption.
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Affiliation(s)
- Blerina Shkembi
- Food Quality & Design Group, Wageningen University & Research, 6708 PB Wageningen, The Netherlands;
| | - Thom Huppertz
- Food Quality & Design Group, Wageningen University & Research, 6708 PB Wageningen, The Netherlands;
- FrieslandCampina, 3818 LE Amersfoort, The Netherlands
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Guo H, Yu Y, Hong Z, Zhang Y, Xie Q, Chen H. Effect of Collagen Peptide-Chelated Zinc Nanoparticles From Pufferfish Skin on Zinc Bioavailability in Rats. J Med Food 2021; 24:987-996. [PMID: 34448624 DOI: 10.1089/jmf.2021.k.0038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Small-molecular-weight collagen peptides (CPs) with high zinc-chelating ability were extracted from pufferfish skin. Chelation of CPs with zinc was performed to prepare novel CP-chelated zinc (CP-Zn) nanoparticles. CP-Zn nanoparticles were spherical, regular, and well dispersed with an average size of ∼100 nm. The zeta potential assay was used to explore the stability of CP-Zn nanoparticles. CP-Zn nanoparticles were much more stable in the pH range of 3-8. The structural properties of CP-Zn nanoparticles were characterized by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry, Fourier transform infrared spectroscopy, and 1H nuclear magnetic resonance spectroscopy. The results indicated that CPs were chelated with Zn ions through the amino nitrogen and oxygen atoms from the carboxyl groups. Furthermore, the animal experiment results showed that CP-Zn nanoparticles were more effective in improving zinc bioavailability of Zn-deficient rats than zinc gluconate and zinc sulfate. The study demonstrated that CP-Zn nanoparticles were ideal for zinc supplementation.
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Affiliation(s)
- Honghui Guo
- Technology Innovation Center for Exploitation of Marine Biological Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen City, China
| | - Yun Yu
- Department of Pharmacology, College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing City, China
| | - Zhuan Hong
- Technology Innovation Center for Exploitation of Marine Biological Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen City, China
| | - Yiping Zhang
- Technology Innovation Center for Exploitation of Marine Biological Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen City, China
| | - Quanling Xie
- Technology Innovation Center for Exploitation of Marine Biological Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen City, China
| | - Hui Chen
- Technology Innovation Center for Exploitation of Marine Biological Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen City, China
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Ruz M, Carrasco F, Rojas P, Codoceo J, Inostroza J, Basfi-Fer K, Csendes A, Papapietro K, Pizarro F, Olivares M, Westcott JL, Hambidge KM, Krebs NF. Zinc absorption and zinc status are reduced after either sleeve gastrectomy or Roux-en-Y gastric bypass in premenopausal women with severe obesity studied prospectively over 24 postoperative months. Am J Clin Nutr 2021; 114:322-329. [PMID: 33829230 DOI: 10.1093/ajcn/nqab039] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 02/02/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Roux-en-Y gastric bypass (RYGBP) is known to reduce zinc absorption; the effects of vertical sleeve gastrectomy (SG) and its long-term implications on zinc absorption have not yet been studied. OBJECTIVE The aim was to evaluate the effects of SG and RYGBP on zinc absorption and zinc status in premenopausal women with severe obesity up to 24 mo after surgery. METHODS Twenty-six premenopausal women undergoing SG [BMI (in kg/m2): 37.3 ± 3.2] and 32 undergoing RYGBP (BMI: 42.0 ± 4.2) were studied. A series of anthropometric, dietary, and zinc status parameters (plasma and hair zinc), and the size of the exchangeable zinc pool (EZP), as well as percentage zinc absorption from a standardized dose using a stable isotope methodology were evaluated in the patients before the surgical procedure and at 12 and 24 mo after SG or RYGBP. SG patients received 15 mg and RYGBP received 25 mg of supplemental Zn/d. RESULTS In premenopausal women, zinc absorption was decreased by 71.9% and 52.0% in SG and RYGBP, respectively, 24 mo postsurgery, compared with initial values. According to 2-factor repeated-measures ANOVA, time effect was significant (P = <0.0001), but not time × group interaction (P = 0.470). Plasma zinc below the cutoff point of 70 µg/dL increased from 0 to 15.4% and 38.1% in SG and RYGBP, respectively. Mean EZP was significantly reduced 24 mo after surgery, although no time × group interactions were observed. Hair zinc did not change across time or between groups. CONCLUSIONS Both SG and RYGBP have profound effects on zinc absorption capacity, which are not compensated for after 24 mo. Although zinc absorption reduction was similar in both types of surgeries, plasma zinc was more affected in RYGBP than SG, despite greater zinc supplementation in RYGBP.This trial was registered at http://www.isrctn.com as ISRCTN31937503.
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Affiliation(s)
- Manuel Ruz
- Department of Nutrition, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Fernando Carrasco
- Department of Nutrition, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Pamela Rojas
- Department of Nutrition, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Juana Codoceo
- Department of Nutrition, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Jorge Inostroza
- Department of Nutrition, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Karen Basfi-Fer
- Department of Nutrition, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Attila Csendes
- Department of Surgery, University of Chile Clinical Hospital, Santiago, Chile
| | - Karin Papapietro
- Department of Surgery, University of Chile Clinical Hospital, Santiago, Chile
| | - Fernando Pizarro
- Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile
| | - Manuel Olivares
- Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile
| | - Jamie L Westcott
- Section of Nutrition, Department of Pediatrics, School of Medicine University of Colorado, Aurora, CO, USA
| | - K Michael Hambidge
- Section of Nutrition, Department of Pediatrics, School of Medicine University of Colorado, Aurora, CO, USA
| | - Nancy F Krebs
- Section of Nutrition, Department of Pediatrics, School of Medicine University of Colorado, Aurora, CO, USA
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Wang D, Liu K, Cui P, Bao Z, Wang T, Lin S, Sun N. Egg-White-Derived Antioxidant Peptide as an Efficient Nanocarrier for Zinc Delivery through the Gastrointestinal System. J Agric Food Chem 2020; 68:2232-2239. [PMID: 31986031 DOI: 10.1021/acs.jafc.9b07770] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
An antioxidant peptide derived from egg white, Asp-His-Thr-Lys-Glu (DHTKE), possesses specific amino acids related to zinc delivery. This study aimed to demonstrate the molecular basis of interactions between the egg white peptide (DHTKE) and zinc ions and investigate the effect of the DHTKE-Zn complex on zinc delivery through the gastrointestinal system. Approximately one DHTKE molecule can bind one zinc ion (n = 1.048 ± 0.085) through its carboxyl, amino, and imidazole nitrogen groups on Asp, His, and Glu. The formed DHTKE-Zn complex presented uniformly distributed globular particles with a particle size of 100-500 nm and underwent dissociation and re-chelation during gastrointestinal digestion. Moreover, the DHTKE peptide mostly remained stable, with a retention rate of 98.32% under gastrointestinal digestion, although one degradation product (DHTK) was identified by nanoscale liquid chromatography-electrospray ionization-tandem mass spectrometry in the gastrointestinal digests; the effectiveness of DHTKE-Zn digests on enhancing absorption of zinc was comparable to that of the initial complex.
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Affiliation(s)
- Di Wang
- National Engineering Research Center of Seafood, School of Food Science and Technology , Dalian Polytechnic University , 1 Qinggongyuan , Ganjingzi District, Dalian , Liaoning 116034 , People's Republic of China
| | - Kexin Liu
- National Engineering Research Center of Seafood, School of Food Science and Technology , Dalian Polytechnic University , 1 Qinggongyuan , Ganjingzi District, Dalian , Liaoning 116034 , People's Republic of China
| | - Pengbo Cui
- National Engineering Research Center of Seafood, School of Food Science and Technology , Dalian Polytechnic University , 1 Qinggongyuan , Ganjingzi District, Dalian , Liaoning 116034 , People's Republic of China
| | - Zhijie Bao
- National Engineering Research Center of Seafood, School of Food Science and Technology , Dalian Polytechnic University , 1 Qinggongyuan , Ganjingzi District, Dalian , Liaoning 116034 , People's Republic of China
| | - Tongtong Wang
- National Engineering Research Center of Seafood, School of Food Science and Technology , Dalian Polytechnic University , 1 Qinggongyuan , Ganjingzi District, Dalian , Liaoning 116034 , People's Republic of China
| | - Songyi Lin
- National Engineering Research Center of Seafood, School of Food Science and Technology , Dalian Polytechnic University , 1 Qinggongyuan , Ganjingzi District, Dalian , Liaoning 116034 , People's Republic of China
| | - Na Sun
- National Engineering Research Center of Seafood, School of Food Science and Technology , Dalian Polytechnic University , 1 Qinggongyuan , Ganjingzi District, Dalian , Liaoning 116034 , People's Republic of China
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Long JM, Mondal P, Westcott JE, Miller LV, Islam MM, Ahmed M, Mahfuz M, Ahmed T, Krebs NF. Zinc Absorption from Micronutrient Powders Is Low in Bangladeshi Toddlers at Risk of Environmental Enteric Dysfunction and May Increase Dietary Zinc Requirements. J Nutr 2019; 149:98-105. [PMID: 30624753 PMCID: PMC6377437 DOI: 10.1093/jn/nxy245] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 08/31/2018] [Indexed: 12/20/2022] Open
Abstract
Background Environmental enteric dysfunction (EED), a chronic inflammatory disorder of the small bowel, is suspected to impair absorption of micronutrients, including zinc. Objective The objective of this study was to compare zinc absorption from micronutrient powder (MNP) over a range of zinc doses in young children screened for EED with use of the lactulose:mannitol ratio (L:M). Methods Bangladeshi children aged 18-24 mo, grouped according to high and low L:M (≥0.09 and <0.09, respectively), were randomly assigned to MNP with 0, 5, 10, or 15 mg Zn/sachet (10 subjects per dose per L:M group). Over a day, fractional absorption of zinc was measured from an MNP-fortified meal and from unfortified meals with stable isotope tracers; total daily absorbed zinc (TAZ, milligrams per day) was determined as the primary outcome. Secondary outcomes included investigation of relations of TAZ to intake, to physiologic requirement, and to other variables, including biomarkers of systemic and intestinal inflammation, using nonlinear models. TAZ was also compared with published data on child zinc absorption. Results In 74 subjects who completed the study, zinc absorption did not differ by L:M grouping. Most biomarkers of intestinal inflammation were elevated in both L:M groups. For combined L:M groups, mean ± SD TAZ for each MNP dose (0, 5, 10, and 15 mg/sachet) was 0.57 ± 0.30, 0.68 ± 0.31, 0.90 ± 0.43, and 1.0 ± 0.39 mg/d, respectively (P = 0.002), and exceeded the estimated physiologic requirement only for the 10- and 15-mg MNP doses. Zinc absorption was notably lower at all intake levels compared with published data (P < 0.0001) and was inversely related to serum α-1 acid glycoprotein and to fecal Entamoeba histolytica (P = 0.02). Conclusion Results indicate impaired absorption of zinc, which may predispose to zinc deficiency in young children with evidence of enteropathy. These findings suggest that current doses of zinc in MNP may be insufficient to yield zinc-related preventative benefits in similar settings. This study is registered at clinicaltrials.gov as NCT02758444.
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Affiliation(s)
- Julie M Long
- University of Colorado School of Medicine, Department of Pediatrics, Section of Nutrition, Aurora, CO
| | - Prasenjit Mondal
- International Center for Diarrheal Disease Research, Bangladesh (icddr,b), Nutrition and Clinical Services Division, Dhaka, Bangladesh
| | - Jamie E Westcott
- University of Colorado School of Medicine, Department of Pediatrics, Section of Nutrition, Aurora, CO
| | - Leland V Miller
- University of Colorado School of Medicine, Department of Pediatrics, Section of Nutrition, Aurora, CO
| | - M Munirul Islam
- International Center for Diarrheal Disease Research, Bangladesh (icddr,b), Nutrition and Clinical Services Division, Dhaka, Bangladesh
| | - Mondar Ahmed
- International Center for Diarrheal Disease Research, Bangladesh (icddr,b), Nutrition and Clinical Services Division, Dhaka, Bangladesh
| | - Mustafa Mahfuz
- International Center for Diarrheal Disease Research, Bangladesh (icddr,b), Nutrition and Clinical Services Division, Dhaka, Bangladesh
| | - Tahmeed Ahmed
- International Center for Diarrheal Disease Research, Bangladesh (icddr,b), Nutrition and Clinical Services Division, Dhaka, Bangladesh
| | - Nancy F Krebs
- University of Colorado School of Medicine, Department of Pediatrics, Section of Nutrition, Aurora, CO,Address correspondence to NFK (e-mail: )
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Hackl L, Speich C, Zeder C, Sánchez-Ferrer A, Adelmann H, de Pee S, Tay F, Zimmermann MB, Moretti D. Cold Extrusion but Not Coating Affects Iron Bioavailability from Fortified Rice in Young Women and Is Associated with Modifications in Starch Microstructure and Mineral Retention during Cooking. J Nutr 2017; 147:2319-2325. [PMID: 29046406 DOI: 10.3945/jn.117.259085] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 08/18/2017] [Accepted: 09/19/2017] [Indexed: 11/14/2022] Open
Abstract
Background: Rice can be fortified with the use of hot or cold extrusion or coating, but the nutritional qualities of the resulting rice grains have never been directly compared.Objective: Using fortified rice produced by coating or hot or cold extrusion, we compared 1) iron and zinc absorption with the use of stable isotopes, 2) iron and zinc retention during cooking, and 3) starch microstructure.Methods: We conducted 2 studies in young women: in study 1 [n = 19; mean ± SD age: 26.2 ± 3.4 y; body mass index (BMI; in kg/m2): 21.3 ± 1.6], we compared the fractional iron absorption (FAFe) from rice meals containing isotopically labeled ferric prophosphate (57FePP), zinc oxide (ZnO), citric acid, and micronutrients fortified through hot extrusion (HER1) with rice meals fortified through cold extrusion containing 57FePP, ZnO, citric acid, and micronutrients (CER); in study 2 (n = 22; age: 24 ± 4 y; BMI: 21.2 ± 1.3), we compared FAFe and fractional zinc absorption (FAZn) from rice meals fortified through hot extrusion (HER2) compared with rice meals fortified through coating containing 57FePP, ZnO, a citric acid and trisodium cirate mixture (CA/TSC), and micronutrients (COR) relative to rice meals extrinsically fortified with ferrous sulfate (reference). Rice types HER1 and CER contained citric acid, whereas types HER2 and COR contained CA/TSC. We assessed retention during standardized cooking experiments and characterized the rice starch microstructure.Results: FAFe (95% CI) was greater from CER [2.2% (1.4%, 3.4%)] than from HER1 [1.2% (0.7%, 2.0%)] (P = 0.036). There was no difference in FAFe between HER2 [5.1% (3.7%, 7.1%)] and COR [4.0% (2.9%, 5.4%)] (P = 0.14), but FAFe from COR was lower than that from the reference meal [6.6% (4.9%, 9.0%)] (P = 0.003), and the geometric mean FAZn (95% CI) did not differ between HER2 [9.5% (7.9%, 11.6%)] and COR [9.6% (8.7%, 10.7%)] (P = 0.92). Cooking in a rice-to-water ratio of 1:2 resulted in iron and zinc retentions >80%, and cooking in excess water did not affect iron retention from hot-extruded rice but caused iron losses of 25% from CER and COR. Distinct variations in starch microstructure were found in CER and HER1.Conclusions: Iron absorption was 64% higher from CER than from hot-extruded rice, with no difference between COR compared with hot-extruded rice. Lower extrusion temperatures may generate a more readily digestible starch structure, allowing for greater iron release in vivo but lower mineral retention during cooking. This trial was registered at clinicaltrials.gov as NCT02176759.
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Affiliation(s)
| | | | | | - Antoni Sánchez-Ferrer
- Laboratory of Food and Soft Materials, Institute of Food, Nutrition and Health, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Horst Adelmann
- Laboratory of Food and Soft Materials, Institute of Food, Nutrition and Health, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | | | - Fabian Tay
- Clinical Trials Center, University Hospital Zurich, Zurich, Switzerland
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11
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Brnić M, Wegmüller R, Melse-Boonstra A, Stomph T, Zeder C, Tay FM, Hurrell RF. Zinc Absorption by Adults Is Similar from Intrinsically Labeled Zinc-Biofortified Rice and from Rice Fortified with Labeled Zinc Sulfate. J Nutr 2016; 146:76-80. [PMID: 26674764 DOI: 10.3945/jn.115.213421] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 10/28/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Biofortification of staple food crops is a promising strategy to combat zinc deficiency, and it is of particular interest for rice and crops that are not consumed as flours and therefore not suitable for postharvest fortification. Because zinc absorption is decreased by phytic acid (PA) and perhaps other dietary components, it is important to measure the absorption of zinc from a biofortified crop before determining its efficacy. OBJECTIVE In this study, we compared the zinc absorption from zinc-biofortified rice (hydroponically enriched with (70)Zn) with that from a control rice of the same variety fortified with (70)ZnSO4 at point of use to reach the same total zinc content of 1.1 mg/meal. Both rice meals had a PA:Zn molar ratio of 12. METHODS Fractional absorption of zinc (FAZ) was measured with the use of the double-isotope tracer ratio method in 16 apparently healthy adults [18-45 y old; BMI (in kg/m(2)) 19-25] who consumed 2 single meals at 4-wk intervals in random order in a crossover design. RESULTS The FAZ from the biofortified rice (mean ± SD: 25.1 ± 8.7%) did not differ significantly from that of the point-of-use fortified rice (mean ± SD: 20.8 ± 7.1%) (P = 0.08). CONCLUSIONS These results suggest that the native zinc accumulated in the biofortified rice was readily released from the rice matrix and that its absorption by adults was influenced by PA and other food components in a similar way to the inorganic zinc compound added to the rice at point of use. Moreover, rice biofortification is likely to be as good as postharvest zinc fortification as an intervention strategy to combat zinc deficiency. This trial was registered at clinicaltrials.gov as NCT01633450.
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Affiliation(s)
- Marica Brnić
- Laboratory of Human Nutrition, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Rita Wegmüller
- Laboratory of Human Nutrition, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | | | - TjeerdJan Stomph
- Centre for Crop Systems Analysis, Wageningen University, Wageningen, Netherlands; and
| | - Christophe Zeder
- Laboratory of Human Nutrition, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Fabian M Tay
- Clinical Trials Center, University and University Hospital Zurich, Zurich, Switzerland
| | - Richard F Hurrell
- Laboratory of Human Nutrition, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
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12
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Galetti V, Kujinga P, Mitchikpè CES, Zeder C, Tay F, Tossou F, Hounhouigan JD, Zimmermann MB, Moretti D. Efficacy of highly bioavailable zinc from fortified water: a randomized controlled trial in rural Beninese children. Am J Clin Nutr 2015; 102:1238-48. [PMID: 26468121 DOI: 10.3945/ajcn.115.117028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 08/19/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Zinc deficiency and contaminated water are major contributors to diarrhea in developing countries. Food fortification with zinc has not shown clear benefits, possibly because of low zinc absorption from inhibitory food matrices. We used a novel point-of-use water ultrafiltration device configured with glass zinc plates to produce zinc-fortified, potable water. OBJECTIVE The objective was to determine zinc bioavailability from filtered water and the efficacy of zinc-fortified water in improving zinc status. DESIGN In a crossover balanced study, we measured fractional zinc absorption (FAZ) from the zinc-fortified water in 18 healthy Swiss adults using zinc stable isotopes and compared it with zinc-fortified maize porridge. We conducted a 20-wk double-blind randomized controlled trial (RCT) in 277 Beninese school children from rural settings who were randomly assigned to receive a daily portion of zinc-fortified filtered water delivering 2.8 mg Zn (Zn+filter), nonfortified filtered water (Filter), or nonfortified nonfiltered water (Pump) from the local improved supply, acting as the control group. The main outcome was plasma zinc concentration (PZn), and the 3 groups were compared by using mixed-effects models. Secondary outcomes were prevalence of zinc deficiency, diarrhea prevalence, and growth. RESULTS Geometric mean (-SD, +SD) FAZ was 7-fold higher from fortified water (65.9%; 42.2, 102.4) than from fortified maize (9.1%; 6.0, 13.7; P < 0.001). In the RCT, a significant time-by-treatment effect on PZn (P = 0.026) and on zinc deficiency (P = 0.032) was found; PZn in the Zn+filter group was significantly higher than in the Filter (P = 0.006) and Pump (P = 0.025) groups. We detected no effect on diarrhea or growth, but our study did not have the duration and power to detect such effects. CONCLUSIONS Consumption of filtered water fortified with a low dose of highly bioavailable zinc is an effective intervention in children from rural African settings. Large community-based trials are needed to assess the effectiveness of zinc-fortified filtered water on diarrhea and growth. These trials were registered at clinicaltrials.gov as NCT01636583 and NCT01790321.
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Affiliation(s)
- Valeria Galetti
- Laboratory of Human Nutrition, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland;
| | - Prosper Kujinga
- Division of Human Nutrition, Wageningen University, Wageningen, Netherlands
| | | | - Christophe Zeder
- Laboratory of Human Nutrition, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Fabian Tay
- Clinical Trials Center, Center for Clinical Research, University Hospital of Zurich, Zurich, Switzerland; and
| | - Félicien Tossou
- Natitingou Health Zone, Ministry of Health, Natitingou, Benin
| | - Joseph D Hounhouigan
- Laboratory of Human Nutrition, Faculty of Agricultural Sciences, Abomey-Calavi University, Cotonou, Benin
| | - Michael B Zimmermann
- Laboratory of Human Nutrition, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Diego Moretti
- Laboratory of Human Nutrition, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
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13
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Miller LV, Hambidge KM, Krebs NF. Zinc Absorption Is Not Related to Dietary Phytate Intake in Infants and Young Children Based on Modeling Combined Data from Multiple Studies. J Nutr 2015; 145:1763-9. [PMID: 26108545 PMCID: PMC4516773 DOI: 10.3945/jn.115.213074] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 05/29/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND It is widely understood that the 2 primary factors affecting dietary zinc absorption in adults are the quantities of zinc and phytate in the diet. Although a similar association of absorption to dietary zinc and phytate is presumed to exist in children, to our knowledge, no large-scale examination of the relation of zinc absorption to dietary and growth factors has been conducted. OBJECTIVE The goal was to apply an adult absorption model and related models to data from zinc absorption studies of infants and children in order to determine the nature of the relation of zinc absorption to dietary zinc and phytate, age, body size, and zinc homeostatic variables. METHODS Data from 236 children between 8 and 50 mo of age were obtained from stable-isotope studies of zinc absorption. Statistical and mechanistic models were fit to the data using linear and nonlinear regression analysis. RESULTS The effect of dietary phytate on zinc absorption when controlling for dietary zinc was very small and not statistically discernable (P = 0.29). A 500-mg/d increase in dietary phytate reduced absorbed zinc by <0.04 mg/d. Absorption was observed to vary with age, weight, and height (P < 0.0001) when controlling for dietary zinc. For example, absorption from 6 mg/d of dietary zinc increased by as much as 0.2 mg/d with a 12-mo increase in age. Absorption varied with weight and exchangeable zinc pool size (0.01 < P < 0.05) when controlling for dietary zinc and age. CONCLUSIONS The absence of a detectable phytate effect on zinc absorption raises caution about use of dietary phytate:zinc molar ratios to predict zinc bioavailability and does not support phytate reduction as a strategy to improve zinc status of young children. The effect of age on zinc absorption and the absence of a phytate effect should facilitate estimations of dietary zinc needs in young children.
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Affiliation(s)
- Leland V Miller
- Section of Nutrition, Department of Pediatrics, University of Colorado Denver School of Medicine, Aurora, CO
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14
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Chomba E, Westcott CM, Westcott JE, Mpabalwani EM, Krebs NF, Patinkin ZW, Palacios N, Hambidge KM. Zinc absorption from biofortified maize meets the requirements of young rural Zambian children. J Nutr 2015; 145:514-9. [PMID: 25733467 PMCID: PMC4770937 DOI: 10.3945/jn.114.204933] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 10/19/2014] [Accepted: 12/22/2014] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The zinc content of maize, a major global food staple, is generally insufficient alone to meet the requirements of young children. OBJECTIVES The primary objective of this study was to determine whether substitution of biofortified maize (34 μg zinc/g grain) for control maize (21 μg zinc/g) was adequate to meet zinc physiologic requirements in young children for whom maize was the major food staple. A secondary objective was to compare total daily zinc absorption when maize flour was fortified with zinc oxide to a total concentration of 60 μg zinc/g. METHODS Participants included 60 rural Zambian children with a mean age of 29 mo who were randomly assigned to receive 1 of 3 maize types (control, biofortified, or fortified) all of which were readily consumed (>100 g on 1 d). Total daily zinc intake (from maize and low-zinc relish) was determined from duplicate diet collections. Multiplication by fractional absorption of zinc, measured by a dual isotope ratio technique, determined the total daily zinc absorption on the day the test meals were given. RESULTS The mean ± SD total daily zinc intake (milligrams per day) from the biofortified maize (5.0 ± 2.2) was higher (P < 0.0001) than for the control maize (2.3 ± 0.9). Intake of zinc from the fortified maize (6.3 ± 2.6) did not differ from the biofortified maize. Fractional absorption of zinc from control maize (0.28 ± 0.10) did not differ from the biofortified maize (0.22 ± 0.06). Total daily absorption of zinc (milligrams per day) from the biofortified maize (1.1 ± 0.5) was higher (P = 0.0001) than for the control maize (0.6 ± 0.2), but did not differ from the fortified maize (1.2 ± 0.4). CONCLUSIONS These results indicate that feeding biofortified maize can meet zinc requirements and provide an effective dietary alternative to regular maize for this vulnerable population. This trial was registered at clinicaltrials.gov as NCT02208635.
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Affiliation(s)
| | - Claire M Westcott
- Section of Nutrition, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO; and
| | - Jamie E Westcott
- Section of Nutrition, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO; and
| | | | - Nancy F Krebs
- Section of Nutrition, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO; and
| | - Zachary W Patinkin
- Section of Nutrition, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO; and
| | - Natalia Palacios
- International Maize and Wheat Improvement Center, Mexico City, Mexico
| | - K Michael Hambidge
- Section of Nutrition, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO; and
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15
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Qin Q, Wang X, Zhou B. Functional studies of Drosophila zinc transporters reveal the mechanism for dietary zinc absorption and regulation. BMC Biol 2013; 11:101. [PMID: 24063361 PMCID: PMC4015762 DOI: 10.1186/1741-7007-11-101] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 09/23/2013] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Zinc is key to the function of many proteins, but the process of dietary zinc absorption is not well clarified. Current knowledge about dietary zinc absorption is fragmented, and mostly derives from incomplete mammalian studies. To gain a comprehensive picture of this process, we systematically characterized all zinc transporters (that is, the Zip and ZnT family members) for their possible roles in dietary zinc absorption in a genetically amenable model organism, Drosophila melanogaster. RESULTS A set of plasma membrane-resident zinc transporters was identified to be responsible for absorbing zinc from the lumen into the enterocyte and the subsequent exit of zinc to the circulation. dZip1 and dZip2, two functionally overlapping zinc importers, are responsible for absorbing zinc from the lumen into the enterocyte. Exit of zinc to the circulation is mediated through another two functionally overlapping zinc exporters, dZnT1, and its homolog CG5130 (dZnT77C). Somewhat surprisingly, it appears that the array of intracellular ZnT proteins, including the Golgi-resident dZnT7, is not directly involved in dietary zinc absorption. By modulating zinc status in different parts of the body, we found that regulation of dietary zinc absorption, in contrast to that of iron, is unresponsive to bodily needs or zinc status outside the gut. The zinc transporters that are involved in dietary zinc absorption, including the importers dZip1 and dZip2, and the exporter dZnT1, are respectively regulated at the RNA and protein levels by zinc in the enterocyte. CONCLUSIONS Our study using the model organism Drosophila thus starts to reveal a comprehensive sketch of dietary zinc absorption and its regulatory control, a process that is still incompletely understood in mammalian organisms. The knowledge gained will act as a reference for future mammalian studies, and also enable an appreciation of this important process from an evolutionary perspective.
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Affiliation(s)
- Qiuhong Qin
- State Key Laboratory of Biomembrane and Membrane Biotechnology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xiaoxi Wang
- State Key Laboratory of Biomembrane and Membrane Biotechnology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Bing Zhou
- State Key Laboratory of Biomembrane and Membrane Biotechnology, School of Life Sciences, Tsinghua University, Beijing 100084, China
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16
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Gaetke LM, McClain CJ, Toleman CJ, Stuart MA. Yogurt protects against growth retardation in weanling rats fed diets high in phytic acid. J Nutr Biochem 2010; 21:147-52. [PMID: 19269152 PMCID: PMC2837909 DOI: 10.1016/j.jnutbio.2008.12.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2008] [Revised: 11/24/2008] [Accepted: 12/10/2008] [Indexed: 11/30/2022]
Abstract
The purpose of this study was to determine the effects of adding yogurt to animal diets that were high in phytic acid (PA) and adequate in zinc (38 microg Zn/g). The PA:Zn molar ratio was 60:1. Zinc status was determined by documenting growth and measuring the zinc concentration in bone (tibia) and plasma. For 25 days, six groups (n=6) of Sprague-Dawley weanling rats were fed one of six AIN-76 diets. Half of the diets contained PA. Four of the diets contained yogurt with either active or heat-treated (inactive) cultures added at 25% of the diet. The diets were as follows: (a) AIN, (b) AIN with active yogurt, (c) AIN and inactive yogurt, (d) AIN with PA, (e) AIN with PA plus active yogurt and (f) AIN with PA plus inactive yogurt. Body weight, weight gain and zinc concentration in bone and plasma were measured, and food efficiency ratio was calculated. Rats fed diets with PA and yogurt had normal growth compared to the control group. Growth retardation was evident in the group fed the diet with PA and no yogurt. This group had significantly lower body weight compared to all other groups (P<.05). Rats fed diets with PA, with or without yogurt, had significantly lower zinc concentration in bone and plasma (P<.05). Adding yogurt to diets high in PA resulted in normal growth in weanling rats; however, zinc concentration in bone and plasma was still suboptimal.
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Affiliation(s)
- Lisa M Gaetke
- Department of Nutrition and Food Science, University of Kentucky, Lexington, KY 40506, USA.
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17
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Cragg RA, Phillips SR, Piper JM, Varma JS, Campbell FC, Mathers JC, Ford D. Homeostatic regulation of zinc transporters in the human small intestine by dietary zinc supplementation. Gut 2005; 54:469-78. [PMID: 15753530 PMCID: PMC1774437 DOI: 10.1136/gut.2004.041962] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Revised: 10/04/2004] [Accepted: 10/12/2004] [Indexed: 12/17/2022]
Abstract
BACKGROUND The role of intestinal transporter regulation in optimising nutrient absorption has been studied extensively in rodent and cell line models but not in human subjects. AIMS The aim of the present study was to investigate the response in vivo of zinc transporters in the human enterocyte to dietary zinc supplementation. SUBJECTS Eighteen patients who had previously undergone ileostomy, all free of any symptoms of inflammatory bowel disease. METHODS Subjects took a daily zinc supplement of 25 mg for 14 days in a double blind, placebo controlled, crossover trial. The effect of the supplement on expression in ileal biopsies of the zinc transporters SLC30A1, SLC30A4, SLC30A5, SLC39A1, SLC39A4, and metallothionein was measured by reverse transcription-polymerase chain reaction RT-PCR. Expression of SLC30A1, SLC30A5, and SLC39A4 was also examined by immunoblotting. RESULTS The zinc supplement reduced SLC30A1 mRNA (1.4-fold) together with SLC30A1, SLC30A5, and SLC39A4 protein (1.8-fold, 3.7-fold, and to undetectable levels, respectively) in ileal mucosa and increased metallothionein mRNA (1.7-fold). The supplement had no effect on expression of SLC30A4 or SLC39A1 mRNA. Localisation of SLC30A5 at the apical human enterocyte/colonocyte membrane and also at the apical membrane of Caco-2 cells was demonstrated by immunohistochemistry. Commensurate with these observations in zinc supplemented human subjects, SLC30A1, SLC30A5, and SLC39A4 mRNA and protein were reduced in Caco-2 cells cultured at 200 muM compared with 100 muM zinc. CONCLUSIONS These observations indicate that, in response to variations in dietary zinc intakes, regulated expression of plasma membrane zinc transporters in the human intestine contributes to maintenance of zinc status.
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Affiliation(s)
- R A Cragg
- Institute for Cell and Molecular Biosciences, University of Newcastle, The Medical School, Newcastle upon Tyne NE2 4HH, UK
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