Comparison of the effects of five dietary fibers on mucosal transcriptional profiles, and luminal microbiota composition and SCFA concentrations in murine colon
SCOPE: The aim of our study was to investigate and compare the effects of five fibers on the mucosal transcriptome, together with alterations in the luminal microbiota composition and SCFA concentrations in the colon. METHODS AND RESULTS: Mice were fed fibers that differed in carbohydrate compositio...
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| Published in | Molecular nutrition & food research Vol. 59; no. 8; pp. 1590 - 1602 |
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| Main Authors | , , , , , , , |
| Format | Journal Article |
| Language | English |
| Published |
Germany
Wiley-VCH
01.08.2015
Blackwell Publishing Ltd |
| Subjects | |
| Online Access | Get full text |
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| Summary: | SCOPE: The aim of our study was to investigate and compare the effects of five fibers on the mucosal transcriptome, together with alterations in the luminal microbiota composition and SCFA concentrations in the colon. METHODS AND RESULTS: Mice were fed fibers that differed in carbohydrate composition or a control diet for 10 days. Colonic gene expression profiles and luminal microbiota composition were determined by microarray techniques, and integrated using multivariate statistics. Our data showed a distinct reaction of the host and microbiota to resistant starch, a fiber that was not completely fermented in the colon, whereas the other fibers induced similar responses on gene expression and microbiota. Consistent associations were revealed between fiber‐induced enrichment of Clostridium cluster IV and XIVa representatives, and changes in mucosal expression of genes related to energy metabolism. The nuclear receptor PPAR‐γ was predicted to be an important regulator of the mucosal responses. CONCLUSION: Results of this exploratory study suggest that despite different sources and composition, fermentable fibers induce a highly similar mucosal response that may at least be partially governed by PPAR‐γ. |
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| Bibliography: | http://dx.doi.org/10.1002/mnfr.201400597 ark:/67375/WNG-RNJMZTBH-S istex:D086CE0570D30612EE7352A561004F1060E7ECD4 Figure s1 Enrichment Map of gene sets that were changed by fiber compared to control. GSEA was performed to identify functional gene sets, i.e. metabolic pathways or signaling transduction routes, that were changed by each fiber compared to control (p < 0.001; FDR < 0.01). Nodes represent functional gene sets, and edges between nodes represent their similarity. A red node indicates induction of a gene set, a blue node indicates suppression of a gene set, and a white node indicate no significant regulation of a gene set by a fiber compared to control. Node size represents the gene set size, and edge thickness represents the degree of overlap between 2 connected gene sets. Gene sets were grouped by cluster analysis, applying the Markov Cluster Algorithm, which were semi-automatically annotated and manually labeled to highlight the prevalent biologic functions among the related gene sets.Figure s2 Upstream regulator analysis. PPAR-γ target genes were determined by Ingenuity Pathway Analysis. A heatmap represents the relative gene expression values for each fiber diet compared to control. Red indicates increased expression, while green indicates decreased expression. The relative gene expression values were log2 transformed, i.e. a fold change of 0.6 means 1.5 fold increase, while -0.6 means -1.5 decrease in expression by the fiber compared to control.Figure s3 Quantitative PCR on total bacteria. 16S rRNA gene-targeted qPCR was used to assess total bacterial numbers. The copy number per 16S rRNA gene was calculated back to total copy number per organ weight.Figure s4 Clustering of MITChip profiles at the probe-level. Pearson distance-based clustering of the samples on log10 transformed probe level data of the MITChip.Figure 5 Representative monomer and oligomer profiles analyzed using HPAEC-PAD. Oligosaccharide profiles of (A) oligofructose (FOS), (B) colonic luminal content of a FOS-fed mouse, as analysed by high performance anion exchange chromatography coupled to pulsed amperometric detection (HPAEC-PAD). The profile of (C) maltodextrin is presented as a comparison.Table s1 Biological processes regulated by dietary fibers. Gene sets significantly regulated (p < 0.001, FDR < 0.01) by dietary fiber compared to control were determined by gene set enrichment analysis. Subsequently, overlapping clusters of gene sets were identified by the Markov Cluster Algorithm, and semi-automatically annotated and manually labeled to highlight the prevalent biologic functions among related gene sets. See Supplemental Figure 1 for a high-resolution version of the maps that includes the names of all gene sets. Arrows indicates increased or decreased expression of genes in the gene sets.Table s2 Common and specific potential upstream regulator in colon of mice after feeding different fiber diets as determined by Ingenuity Systems Pathway Analysis Software Transcriptional regulator and ligand-dependent nuclear receptor which showed an absolute activation z-score ≥ 2 and a p-value < 0.05 are displayedTable s3Supplementary Info. ArticleID:MNFR2396 These authors contributed equally to this work. Current address: Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom See the article online to view Fig. 1,2,4 and 5 in colour. Colour Online ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
| ISSN: | 1613-4125 1613-4133 |
| DOI: | 10.1002/mnfr.201400597 |