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Glycan complexity dictates microbial resource allocation in the large intestine.

Rogowski A, Briggs JA, Mortimer JC, Tryfona T, Terrapon N, Lowe EC, Baslé A, Morland C, Day AM, Zheng H, Rogers TE, Thompson P, Hawkins AR, Yadav MP, Henrissat B, Martens EC, Dupree P, Gilbert HJ, Bolam DN - Nat Commun (2015)

Bottom Line: We show here, using xylan as a model, that sharing the breakdown products of complex carbohydrates by key members of the microbiota, such as Bacteroides ovatus, is dependent on the complexity of the target glycan.Characterization of the extensive xylan degrading apparatus expressed by B. ovatus reveals that the breakdown of the polysaccharide by the human gut microbiota is significantly more complex than previous models suggested, which were based on the deconstruction of xylans containing limited monosaccharide side chains.Our report presents a highly complex and dynamic xylan degrading apparatus that is fine-tuned to recognize the different forms of the polysaccharide presented to the human gut microbiota.

View Article: PubMed Central - PubMed

Affiliation: Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.

ABSTRACT
The structure of the human gut microbiota is controlled primarily through the degradation of complex dietary carbohydrates, but the extent to which carbohydrate breakdown products are shared between members of the microbiota is unclear. We show here, using xylan as a model, that sharing the breakdown products of complex carbohydrates by key members of the microbiota, such as Bacteroides ovatus, is dependent on the complexity of the target glycan. Characterization of the extensive xylan degrading apparatus expressed by B. ovatus reveals that the breakdown of the polysaccharide by the human gut microbiota is significantly more complex than previous models suggested, which were based on the deconstruction of xylans containing limited monosaccharide side chains. Our report presents a highly complex and dynamic xylan degrading apparatus that is fine-tuned to recognize the different forms of the polysaccharide presented to the human gut microbiota.

No MeSH data available.


Related in: MedlinePlus

Schematic of the structures of the main classes of xylan.The monosaccharides and linkages in the main classes of xylan are shown and are represented in their Consortium for Functional Glycomics format69. The xylans used in this study were from birchwood (birch glucuronoxylan; BGX), wheat flour (wheat arabinoxylan; WAX) and corn bran (corn glucuronoarabinoxylan; CX).
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f1: Schematic of the structures of the main classes of xylan.The monosaccharides and linkages in the main classes of xylan are shown and are represented in their Consortium for Functional Glycomics format69. The xylans used in this study were from birchwood (birch glucuronoxylan; BGX), wheat flour (wheat arabinoxylan; WAX) and corn bran (corn glucuronoarabinoxylan; CX).

Mentions: Xylan, a major component of many plant cell walls, is one of the most variable plant structural polysaccharides, and is a common component of cereal-derived human foods131415. The main classes of xylan are the glucuronoxylans (GXs), arabinoxylans (AXs) and glucuronoarabinoxylans (GAXs). The designation of these three polysaccharides reflects the nature of the monosaccharides that decorate the conserved β1,4-xylose (Xyl) backbone (Fig. 1). Many GXs and AXs are relatively simple. In contrast, the number and complexity of the side chains on cereal GAXs, exemplified by corn bran xylan (CX) (Fig. 1) explains why these glycans are recalcitrant to breakdown by known xylan-degrading enzyme systems13.


Glycan complexity dictates microbial resource allocation in the large intestine.

Rogowski A, Briggs JA, Mortimer JC, Tryfona T, Terrapon N, Lowe EC, Baslé A, Morland C, Day AM, Zheng H, Rogers TE, Thompson P, Hawkins AR, Yadav MP, Henrissat B, Martens EC, Dupree P, Gilbert HJ, Bolam DN - Nat Commun (2015)

Schematic of the structures of the main classes of xylan.The monosaccharides and linkages in the main classes of xylan are shown and are represented in their Consortium for Functional Glycomics format69. The xylans used in this study were from birchwood (birch glucuronoxylan; BGX), wheat flour (wheat arabinoxylan; WAX) and corn bran (corn glucuronoarabinoxylan; CX).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4491172&req=5

f1: Schematic of the structures of the main classes of xylan.The monosaccharides and linkages in the main classes of xylan are shown and are represented in their Consortium for Functional Glycomics format69. The xylans used in this study were from birchwood (birch glucuronoxylan; BGX), wheat flour (wheat arabinoxylan; WAX) and corn bran (corn glucuronoarabinoxylan; CX).
Mentions: Xylan, a major component of many plant cell walls, is one of the most variable plant structural polysaccharides, and is a common component of cereal-derived human foods131415. The main classes of xylan are the glucuronoxylans (GXs), arabinoxylans (AXs) and glucuronoarabinoxylans (GAXs). The designation of these three polysaccharides reflects the nature of the monosaccharides that decorate the conserved β1,4-xylose (Xyl) backbone (Fig. 1). Many GXs and AXs are relatively simple. In contrast, the number and complexity of the side chains on cereal GAXs, exemplified by corn bran xylan (CX) (Fig. 1) explains why these glycans are recalcitrant to breakdown by known xylan-degrading enzyme systems13.

Bottom Line: We show here, using xylan as a model, that sharing the breakdown products of complex carbohydrates by key members of the microbiota, such as Bacteroides ovatus, is dependent on the complexity of the target glycan.Characterization of the extensive xylan degrading apparatus expressed by B. ovatus reveals that the breakdown of the polysaccharide by the human gut microbiota is significantly more complex than previous models suggested, which were based on the deconstruction of xylans containing limited monosaccharide side chains.Our report presents a highly complex and dynamic xylan degrading apparatus that is fine-tuned to recognize the different forms of the polysaccharide presented to the human gut microbiota.

View Article: PubMed Central - PubMed

Affiliation: Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.

ABSTRACT
The structure of the human gut microbiota is controlled primarily through the degradation of complex dietary carbohydrates, but the extent to which carbohydrate breakdown products are shared between members of the microbiota is unclear. We show here, using xylan as a model, that sharing the breakdown products of complex carbohydrates by key members of the microbiota, such as Bacteroides ovatus, is dependent on the complexity of the target glycan. Characterization of the extensive xylan degrading apparatus expressed by B. ovatus reveals that the breakdown of the polysaccharide by the human gut microbiota is significantly more complex than previous models suggested, which were based on the deconstruction of xylans containing limited monosaccharide side chains. Our report presents a highly complex and dynamic xylan degrading apparatus that is fine-tuned to recognize the different forms of the polysaccharide presented to the human gut microbiota.

No MeSH data available.


Related in: MedlinePlus