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Starch and starch hydrolysates are favorable carbon sources for Bifidobacteria in the human gut

BACKGROUND: Bifidobacteria are key commensals in human gut, and their abundance is associated with the health of their hosts. Although they are dominant in infant gut, their number becomes lower in adult gut. The changes of the diet are considered to be main reason for this difference. Large amounts...

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Autores principales: Liu, Songling, Ren, Fazheng, Zhao, Liang, Jiang, Lu, Hao, Yanling, Jin, Junhua, Zhang, Ming, Guo, Huiyuan, Lei, Xingen, Sun, Erna, Liu, Hongna
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4349234/
https://www.ncbi.nlm.nih.gov/pubmed/25887661
http://dx.doi.org/10.1186/s12866-015-0362-3
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author Liu, Songling
Ren, Fazheng
Zhao, Liang
Jiang, Lu
Hao, Yanling
Jin, Junhua
Zhang, Ming
Guo, Huiyuan
Lei, Xingen
Sun, Erna
Liu, Hongna
author_facet Liu, Songling
Ren, Fazheng
Zhao, Liang
Jiang, Lu
Hao, Yanling
Jin, Junhua
Zhang, Ming
Guo, Huiyuan
Lei, Xingen
Sun, Erna
Liu, Hongna
author_sort Liu, Songling
collection PubMed
description BACKGROUND: Bifidobacteria are key commensals in human gut, and their abundance is associated with the health of their hosts. Although they are dominant in infant gut, their number becomes lower in adult gut. The changes of the diet are considered to be main reason for this difference. Large amounts of whole-genomic sequence data of bifidobacteria make it possible to elucidate the genetic interpretation of their adaptation to the nutrient environment. Among the nutrients in human gut, starch is a highly fermentable substrate and can exert beneficial effects by increasing bifidobacteria and/or being fermented to short chain fatty acids. RESULTS: In order to determine the potential substrate preference of bifidobacteria, we compared the glycoside hydrolase (GH) profiles of a pooled-bifidobacterial genome (PBG) with a representative microbiome (RM) of the human gut. In bifidobacterial genomes, only 15% of GHs contained signal peptides, suggesting their weakness in utilization of complex carbohydrate, such as plant cell wall polysaccharides. However, compared with other intestinal bacteria, bifidobacteiral genomes encoded more GH genes for degrading starch and starch hydrolysates, indicating that they have genetic advantages in utilizing these substrates. Bifidobacterium longum subsp. longum BBMN68 isolated from centenarian’s faeces was used as a model strain to further investigate the carbohydrate utilization. The pathway for degrading starch and starch hydrolysates was the only complete pathway for complex carbohydrates in human gut. It is noteworthy that all of the GH genes for degrading starch and starch hydrolysates in the BBMN68 genome were conserved in all studied bifidobacterial strains. The in silico analyses of BBMN68 were further confirmed by growth experiments, proteomic and real-time quantitative PCR (RT-PCR) analyses. CONCLUSIONS: Our results demonstrated that starch and starch hydrolysates were the most universal and favorable carbon sources for bifidobacteria. The low amount of these carbon sources in adult intestine was speculated to contribute to the low relative abundance of bifidobacteria. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12866-015-0362-3) contains supplementary material, which is available to authorized users.
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spelling pubmed-43492342015-03-05 Starch and starch hydrolysates are favorable carbon sources for Bifidobacteria in the human gut Liu, Songling Ren, Fazheng Zhao, Liang Jiang, Lu Hao, Yanling Jin, Junhua Zhang, Ming Guo, Huiyuan Lei, Xingen Sun, Erna Liu, Hongna BMC Microbiol Research Article BACKGROUND: Bifidobacteria are key commensals in human gut, and their abundance is associated with the health of their hosts. Although they are dominant in infant gut, their number becomes lower in adult gut. The changes of the diet are considered to be main reason for this difference. Large amounts of whole-genomic sequence data of bifidobacteria make it possible to elucidate the genetic interpretation of their adaptation to the nutrient environment. Among the nutrients in human gut, starch is a highly fermentable substrate and can exert beneficial effects by increasing bifidobacteria and/or being fermented to short chain fatty acids. RESULTS: In order to determine the potential substrate preference of bifidobacteria, we compared the glycoside hydrolase (GH) profiles of a pooled-bifidobacterial genome (PBG) with a representative microbiome (RM) of the human gut. In bifidobacterial genomes, only 15% of GHs contained signal peptides, suggesting their weakness in utilization of complex carbohydrate, such as plant cell wall polysaccharides. However, compared with other intestinal bacteria, bifidobacteiral genomes encoded more GH genes for degrading starch and starch hydrolysates, indicating that they have genetic advantages in utilizing these substrates. Bifidobacterium longum subsp. longum BBMN68 isolated from centenarian’s faeces was used as a model strain to further investigate the carbohydrate utilization. The pathway for degrading starch and starch hydrolysates was the only complete pathway for complex carbohydrates in human gut. It is noteworthy that all of the GH genes for degrading starch and starch hydrolysates in the BBMN68 genome were conserved in all studied bifidobacterial strains. The in silico analyses of BBMN68 were further confirmed by growth experiments, proteomic and real-time quantitative PCR (RT-PCR) analyses. CONCLUSIONS: Our results demonstrated that starch and starch hydrolysates were the most universal and favorable carbon sources for bifidobacteria. The low amount of these carbon sources in adult intestine was speculated to contribute to the low relative abundance of bifidobacteria. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12866-015-0362-3) contains supplementary material, which is available to authorized users. BioMed Central 2015-03-01 /pmc/articles/PMC4349234/ /pubmed/25887661 http://dx.doi.org/10.1186/s12866-015-0362-3 Text en © Liu et al.; licensee BioMed Central. 2015 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research Article
Liu, Songling
Ren, Fazheng
Zhao, Liang
Jiang, Lu
Hao, Yanling
Jin, Junhua
Zhang, Ming
Guo, Huiyuan
Lei, Xingen
Sun, Erna
Liu, Hongna
Starch and starch hydrolysates are favorable carbon sources for Bifidobacteria in the human gut
title Starch and starch hydrolysates are favorable carbon sources for Bifidobacteria in the human gut
title_full Starch and starch hydrolysates are favorable carbon sources for Bifidobacteria in the human gut
title_fullStr Starch and starch hydrolysates are favorable carbon sources for Bifidobacteria in the human gut
title_full_unstemmed Starch and starch hydrolysates are favorable carbon sources for Bifidobacteria in the human gut
title_short Starch and starch hydrolysates are favorable carbon sources for Bifidobacteria in the human gut
title_sort starch and starch hydrolysates are favorable carbon sources for bifidobacteria in the human gut
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4349234/
https://www.ncbi.nlm.nih.gov/pubmed/25887661
http://dx.doi.org/10.1186/s12866-015-0362-3
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