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A nine-country study of the protein content and amino acid composition of mature human milk
BACKGROUND: Numerous studies have evaluated protein and amino acid levels in human milk. However, research in this area has been limited by small sample sizes and study populations with little ethnic or racial diversity. OBJECTIVE: Evaluate the protein and amino acid composition of mature (≥30 days)...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Co-Action Publishing
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5002399/ https://www.ncbi.nlm.nih.gov/pubmed/27569428 http://dx.doi.org/10.3402/fnr.v60.31042 |
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author | Feng, Ping Gao, Ming Burgher, Anita Zhou, Tian Hui Pramuk, Kathryn |
author_facet | Feng, Ping Gao, Ming Burgher, Anita Zhou, Tian Hui Pramuk, Kathryn |
author_sort | Feng, Ping |
collection | PubMed |
description | BACKGROUND: Numerous studies have evaluated protein and amino acid levels in human milk. However, research in this area has been limited by small sample sizes and study populations with little ethnic or racial diversity. OBJECTIVE: Evaluate the protein and amino acid composition of mature (≥30 days) human milk samples collected from a large, multinational study using highly standardized methods for sample collection, storage, and analysis. DESIGN: Using a single, centralized laboratory, human milk samples from 220 women (30–188 days postpartum) from nine countries were analyzed for amino acid composition using Waters AccQ-Tag high-performance liquid chromatography and total nitrogen content using the LECO FP-528 nitrogen analyzer. Total protein was calculated as total nitrogen×6.25. True protein, which includes protein, free amino acids, and peptides, was calculated from the total amino acids. RESULTS: Mean total protein from individual countries (standard deviation [SD]) ranged from 1,133 (125.5) to 1,366 (341.4) mg/dL; the mean across all countries (SD) was 1,192 (200.9) mg/dL. Total protein, true protein, and amino acid composition were not significantly different across countries except Chile, which had higher total and true protein. Amino acid profiles (percent of total amino acids) did not differ across countries. Total and true protein concentrations and 16 of 18 amino acid concentrations declined with the stage of lactation. CONCLUSIONS: Total protein, true protein, and individual amino acid concentrations in human milk steadily decline from 30 to 151 days of lactation, and are significantly higher in the second month of lactation compared with the following 4 months. There is a high level of consistency in the protein content and amino acid composition of human milk across geographic locations. The size and diversity of the study population and highly standardized procedures for the collection, storage, and analysis of human milk support the validity and broad application of these findings. |
format | Online Article Text |
id | pubmed-5002399 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Co-Action Publishing |
record_format | MEDLINE/PubMed |
spelling | pubmed-50023992016-09-07 A nine-country study of the protein content and amino acid composition of mature human milk Feng, Ping Gao, Ming Burgher, Anita Zhou, Tian Hui Pramuk, Kathryn Food Nutr Res Original Article BACKGROUND: Numerous studies have evaluated protein and amino acid levels in human milk. However, research in this area has been limited by small sample sizes and study populations with little ethnic or racial diversity. OBJECTIVE: Evaluate the protein and amino acid composition of mature (≥30 days) human milk samples collected from a large, multinational study using highly standardized methods for sample collection, storage, and analysis. DESIGN: Using a single, centralized laboratory, human milk samples from 220 women (30–188 days postpartum) from nine countries were analyzed for amino acid composition using Waters AccQ-Tag high-performance liquid chromatography and total nitrogen content using the LECO FP-528 nitrogen analyzer. Total protein was calculated as total nitrogen×6.25. True protein, which includes protein, free amino acids, and peptides, was calculated from the total amino acids. RESULTS: Mean total protein from individual countries (standard deviation [SD]) ranged from 1,133 (125.5) to 1,366 (341.4) mg/dL; the mean across all countries (SD) was 1,192 (200.9) mg/dL. Total protein, true protein, and amino acid composition were not significantly different across countries except Chile, which had higher total and true protein. Amino acid profiles (percent of total amino acids) did not differ across countries. Total and true protein concentrations and 16 of 18 amino acid concentrations declined with the stage of lactation. CONCLUSIONS: Total protein, true protein, and individual amino acid concentrations in human milk steadily decline from 30 to 151 days of lactation, and are significantly higher in the second month of lactation compared with the following 4 months. There is a high level of consistency in the protein content and amino acid composition of human milk across geographic locations. The size and diversity of the study population and highly standardized procedures for the collection, storage, and analysis of human milk support the validity and broad application of these findings. Co-Action Publishing 2016-08-26 /pmc/articles/PMC5002399/ /pubmed/27569428 http://dx.doi.org/10.3402/fnr.v60.31042 Text en © 2016 Ping Feng et al. http://creativecommons.org/licenses/by/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 International License, allowing third parties to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material for any purpose, even commercially, provided the original work is properly cited and states its license. |
spellingShingle | Original Article Feng, Ping Gao, Ming Burgher, Anita Zhou, Tian Hui Pramuk, Kathryn A nine-country study of the protein content and amino acid composition of mature human milk |
title | A nine-country study of the protein content and amino acid composition of mature human milk |
title_full | A nine-country study of the protein content and amino acid composition of mature human milk |
title_fullStr | A nine-country study of the protein content and amino acid composition of mature human milk |
title_full_unstemmed | A nine-country study of the protein content and amino acid composition of mature human milk |
title_short | A nine-country study of the protein content and amino acid composition of mature human milk |
title_sort | nine-country study of the protein content and amino acid composition of mature human milk |
topic | Original Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5002399/ https://www.ncbi.nlm.nih.gov/pubmed/27569428 http://dx.doi.org/10.3402/fnr.v60.31042 |
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