title: A combined metabolomic and phylogenetic study reveals putatively prebiotic effects of high molecular weight arabino-oligosaccharides when assessed by in vitro fermentation in bacterial communities derived from humans.
abstract: Prebiotic oligosaccharides are defined by their selective stimulation of growth and/or activity of bacteria in the digestive system in ways claimed to be beneficial for health. However, apart from the short chain fatty acids, little is known about bacterial metabolites created by fermentation of prebiotics, and the significance of the size of the oligosaccharides remains largely unstudied. By in vitro fermentations in human fecal microbial communities (derived from six different individuals), we studied the effects of high-mass (HA, >1 kDa), low-mass (LA, <1 kDa) and mixed (BA) sugar beet arabino-oligosaccharides (AOS) as carbohydrate sources. Fructo-oligosaccharides (FOS) were included as reference. The changes in bacterial communities and the metabolites produced in response to incubation with the different carbohydrates were analyzed by quantitative PCR (qPCR) and Liquid Chromatography-Mass Spectrometry (LC-MS), respectively. All tested carbohydrate sources resulted in a significant increase of Bifidobacterium spp. between 1.79 fold (HA) and 1.64 fold (FOS) in the microbial populations after fermentation, and LC-MS analysis suggested that the bifidobacteria contributed to decomposition of the arabino-oligosaccharide structures, most pronounced in the HA fraction, resulting in release of the essential amino acid phenylalanine. Abundance of Lactobacillus spp. correlated with the presence of a compound, most likely a flavonoid, indicating that lactobacilli contribute to release of such health-promoting substances from plant structures. Additionally, the combination of qPCR and LC-MS revealed a number of other putative interactions between intestinal microbes and the oligosaccharides, which contributes to the understanding of the mechanisms behind prebiotic impact on human health.
authors.affiliation: Division of Food Microbiology, DTU Food, Technical University of Denmark, Mørkhøj Bygade 19, 2860 Søborg, Denmark.
authors.forename: Karolina
authors.initials: K
authors.lastname: Sulek
authors.affiliation: Division of Food Microbiology, DTU Food, Technical University of Denmark, Mørkhøj Bygade 19, 2860 Søborg, Denmark.
authors.forename: Louise Kristine
authors.initials: LK
authors.lastname: Vigsnaes
authors.affiliation: Division of Food Microbiology, DTU Food, Technical University of Denmark, Mørkhøj Bygade 19, 2860 Søborg, Denmark.
authors.forename: Line Rieck
authors.initials: LR
authors.lastname: Schmidt
authors.affiliation: Department of Chemical and Biochemical Engineering, DTU Chemical Engineering, Technical University of Denmark, Søltofts Plads, 2800 Kgs. Lyngby, Denmark.
authors.forename: Jesper
authors.initials: J
authors.lastname: Holck
authors.affiliation: Division of Food Chemistry, DTU Food, Technical University of Denmark, Mørkhøj Bygade 19, 2860 Søborg, Denmark.
authors.forename: Henrik Lauritz
authors.initials: HL
authors.lastname: Frandsen
authors.affiliation: Division of Food Chemistry, DTU Food, Technical University of Denmark, Mørkhøj Bygade 19, 2860 Søborg, Denmark.
authors.forename: Jørn
authors.initials: J
authors.lastname: Smedsgaard
authors.affiliation: Division of Quality and Technology, Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 30, 1958 Frederiksberg-C, Denmark.
authors.forename: Thomas Hjort
authors.initials: TH
authors.lastname: Skov
authors.affiliation: Department of Chemical and Biochemical Engineering, DTU Chemical Engineering, Technical University of Denmark, Søltofts Plads, 2800 Kgs. Lyngby, Denmark.
authors.forename: Anne S
authors.initials: AS
authors.lastname: Meyer
authors.affiliation: Division of Food Microbiology, DTU Food, Technical University of Denmark, Mørkhøj Bygade 19, 2860 Søborg, Denmark. Electronic address: trli@food.dtu.dk.
authors.forename: Tine Rask
authors.initials: TR
authors.lastname: Licht
mesh_terms: D000328:Adult; D001419:Bacteria / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D002853:Chromatography, Liquid; D005260:Female; D005285:Fermentation; D041981:Gastrointestinal Tract / Q000382:microbiology*; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D055442:Metabolome; D064307:Microbiota / Q000187:drug effects*; D008875:Middle Aged; D008970:Molecular Weight; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism*; D010802:Phylogeny; D056692:Prebiotics; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D009844:Oligosaccharides; D056692:Prebiotics
keywords: Arabino-oligosaccharides; Intestinal microbial metabolism; Prebiotics