title: Mutual Cross-Feeding Interactions between Bifidobacterium longum subsp. longum NCC2705 and Eubacterium rectale ATCC 33656 Explain the Bifidogenic and Butyrogenic Effects of Arabinoxylan Oligosaccharides.
abstract: Arabinoxylan oligosaccharides (AXOS) are a promising class of prebiotics that have the potential to stimulate the growth of bifidobacteria and the production of butyrate in the human colon, known as the bifidogenic and butyrogenic effects, respectively. Although these dual effects of AXOS are considered beneficial for human health, their underlying mechanisms are still far from being understood. Therefore, this study investigated the metabolic interactions between Bifidobacterium longum subsp. longum NCC2705 (B. longum NCC2705), an acetate producer and arabinose substituent degrader of AXOS, and Eubacterium rectale ATCC 33656, an acetate-converting butyrate producer. Both strains belong to prevalent species of the human colon microbiota. The strains were grown on AXOS during mono- and coculture fermentations, and their growth, AXOS consumption, metabolite production, and expression of key genes were monitored. The results showed that the growth of both strains and gene expression in both strains were affected by cocultivation and that these effects could be linked to changes in carbohydrate consumption and concomitant metabolite production. The consumption of the arabinose substituents of AXOS by B. longum NCC2705 with the concomitant production of acetate allowed E. rectale ATCC 33656 to produce butyrate (by means of a butyryl coenzyme A [CoA]:acetate CoA-transferase), explaining the butyrogenic effect of AXOS. Eubacterium rectale ATCC 33656 released xylose from the AXOS substrate, which favored the B. longum NCC2705 production of acetate, explaining the bifidogenic effect of AXOS. Hence, those interactions represent mutual cross-feeding mechanisms that favor the coexistence of bifidobacterial strains and butyrate producers in the same ecological niche. In conclusion, this study provides new insights into the bifidogenic and butyrogenic effects of AXOS.
authors: Research Group of Industrial Microbiology and Food Biotechnology, Vrije Universiteit Brussel, Brussels, Belgium.
authors: Audrey
authors: A
authors: Rivière
authors: Département des Sciences des Aliments, Institut sur la Nutrition et les Aliments Fonctionnels (INAF), Université Laval, Québec, Québec, Canada.
authors: Mérilie
authors: M
authors: Gagnon
authors: Research Group of Industrial Microbiology and Food Biotechnology, Vrije Universiteit Brussel, Brussels, Belgium.
authors: Stefan
authors: S
authors: Weckx
authors: Département des Sciences des Aliments, Institut sur la Nutrition et les Aliments Fonctionnels (INAF), Université Laval, Québec, Québec, Canada.
authors: Denis
authors: D
authors: Roy
authors: Research Group of Industrial Microbiology and Food Biotechnology, Vrije Universiteit Brussel, Brussels, Belgium ldvuyst@vub.ac.be.
authors: Luc
authors: L
authors: De Vuyst
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001644:Bifidobacterium / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D005051:Eubacterium / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D015870:Gene Expression; D009844:Oligosaccharides / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014990:Xylans / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D009844:Oligosaccharides; D014990:Xylans; C085118:arabinoxylan