title: Colonic metaproteomic signatures of active bacteria and the host in obesity.
abstract: Obesity is associated with the intestinal microbiota in humans but the underlying mechanisms are yet to be fully understood. Our previous phylogenetic study showed that the faecal microbiota profiles of nonobese versus obese and morbidly obese individuals differed. Here, we have extended this analysis with a characterization of the faecal metaproteome, in order to detect differences at a functional level. Proteins were extracted from crude faecal samples of 29 subjects, separated by 1D gel electrophoresis and characterized using RP LC-MS/MS. The peptide data were analyzed in database searches with two complementary algorithms, OMSSA and X!Tandem, to increase the number of identifications. Evolutionary genealogy of genes: nonsupervised orthologous groups (EggNOG) database searches resulted in the functional annotation of over 90% of the identified microbial and human proteins. Based on both bacterial and human proteins, a clear clustering of obese and nonobese samples was obtained that exceeded the phylogenetic separation in dimension. Moreover, integration of the metaproteomics and phylogenetic datasets revealed notably that the phylum Bacteroidetes was metabolically more active in the obese than nonobese subjects. Finally, significant correlations between clinical measurements and bacterial gene functions were identified. This study emphasizes the importance of integrating data of the host and microbiota to understand their interactions.
authors.affiliation: Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland.
authors.forename: Carolin A
authors.initials: CA
authors.lastname: Kolmeder
authors.affiliation: Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland.
authors.forename: Jarmo
authors.initials: J
authors.lastname: Ritari
authors.affiliation: Department of General Surgery, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Froukje J
authors.initials: FJ
authors.lastname: Verdam
authors.affiliation: Max Planck Institute for Dynamics of Complex Technical Systems, Bioprocess Engineering, Magdeburg, Germany.
authors.forename: Thilo
authors.initials: T
authors.lastname: Muth
authors.affiliation: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors.forename: Salla
authors.initials: S
authors.lastname: Keskitalo
authors.affiliation: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors.forename: Markku
authors.initials: M
authors.lastname: Varjosalo
authors.affiliation: Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands.
authors.forename: Susana
authors.initials: S
authors.lastname: Fuentes
authors.affiliation: Department of General Surgery, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Jan Willem
authors.initials: JW
authors.lastname: Greve
authors.affiliation: Department of General Surgery, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Wim A
authors.initials: WA
authors.lastname: Buurman
authors.affiliation: Max Planck Institute for Dynamics of Complex Technical Systems, Bioprocess Engineering, Magdeburg, Germany.|Chair of Bioprocess Engineering, Otto-von-Guericke University, Magdeburg, Germany.
authors.forename: Udo
authors.initials: U
authors.lastname: Reichl
authors.affiliation: Max Planck Institute for Dynamics of Complex Technical Systems, Bioprocess Engineering, Magdeburg, Germany.
authors.forename: Erdmann
authors.initials: E
authors.lastname: Rapp
authors.affiliation: Department of Biochemistry, Ghent University, Ghent, Belgium.|VIB Medical Biotechnology Center, Department of Medical Protein Research, Ghent, Belgium.
authors.forename: Lennart
authors.initials: L
authors.lastname: Martens
authors.affiliation: Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland.
authors.forename: Airi
authors.initials: A
authors.lastname: Palva
authors.affiliation: Department of Bacteriology and Immunology, Immunobiology Research Program, University of Helsinki, Helsinki, Finland.
authors.forename: Anne
authors.initials: A
authors.lastname: Salonen
authors.affiliation: Department of General Surgery, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Sander S
authors.initials: SS
authors.lastname: Rensen
authors.affiliation: Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland.|Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands.|Department of Bacteriology and Immunology, Immunobiology Research Program, University of Helsinki, Helsinki, Finland.
authors.forename: Willem M
authors.initials: WM
authors.lastname: de Vos
mesh_terms: D000328:Adult; D001439:Bacteroides / Q000235:genetics / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology; D005260:Female; D041981:Gastrointestinal Tract / Q000382:microbiology* / Q000473:pathology; D006801:Humans; D008297:Male; D064307:Microbiota / Q000235:genetics*; D009767:Obesity, Morbid / Q000235:genetics* / Q000382:microbiology / Q000473:pathology; D010802:Phylogeny; D018720:Prevotella / Q000235:genetics / Q000302:isolation & purification; D020543:Proteome / Q000235:genetics*; D053719:Tandem Mass Spectrometry
chemical_list: D020543:Proteome
keywords: Composition; Intestinal microbiota; Metaproteomics; Microbiology; Obesity