title: Dominant components of the Thoroughbred metabolome characterised by (1) H-nuclear magnetic resonance spectroscopy: A metabolite atlas of common biofluids.
abstract: BACKGROUND
  Metabonomics is emerging as a powerful tool for disease screening and investigating mammalian metabolism. This study aims to create a metabolic framework by producing a preliminary reference guide for the normal equine metabolic milieu.
  
  
  OBJECTIVE
  To metabolically profile plasma, urine and faecal water from healthy racehorses using high resolution (1) H-nuclear magnetic resonance (NMR) spectroscopy and to provide a list of dominant metabolites present in each biofluid for the benefit of future research in this area.
  
  
  METHODS
  This study was performed using 7 Thoroughbreds in race training at a single time point. Urine and faecal samples were collected noninvasively and plasma was obtained from samples taken for routine clinical chemistry purposes.
  
  
  METHODS
  Biofluids were analysed using (1) H-NMR spectroscopy. Metabolite assignment was achieved via a range of one- and 2-dimensional experiments.
  
  
  RESULTS
  A total of 102 metabolites were assigned across the 3 biological matrices. A core metabonome of 14 metabolites was ubiquitous across all biofluids. All biological matrices provided a unique window on different aspects of systematic metabolism. Urine was the most populated metabolite matrix with 65 identified metabolites, 39 of which were unique to this biological compartment. A number of these were related to gut microbial host cometabolism. Faecal samples were the most metabolically variable between animals; acetate was responsible for the majority (28%) of this variation. Short-chain fatty acids were the predominant features identified within this biofluid by (1) H-NMR spectroscopy.
  
  
  CONCLUSIONS
  Metabonomics provides a platform for investigating complex and dynamic interactions between the host and its consortium of gut microbes and has the potential to uncover markers for health and disease in a variety of biofluids. Inherent variation in faecal extracts along with the relative abundance of microbial-mammalian metabolites in urine and invasive nature of plasma sampling, infers that urine is the most appropriate biofluid for the purposes of metabonomic analysis.
authors.affiliation: Section of Biomolecular Medicine, Division of Computational and Systems Medicine, Faculty of Medicine, Imperial College London, UK.
authors.forename: E E
authors.initials: EE
authors.lastname: Escalona
authors.affiliation: Department of Food and Nutritional Sciences, University of Reading, Berkshire, UK.
authors.forename: J
authors.initials: J
authors.lastname: Leng
authors.affiliation: Section of Biomolecular Medicine, Division of Computational and Systems Medicine, Faculty of Medicine, Imperial College London, UK.
authors.forename: A C
authors.initials: AC
authors.lastname: Dona
authors.affiliation: Section of Biomolecular Medicine, Division of Computational and Systems Medicine, Faculty of Medicine, Imperial College London, UK.
authors.forename: C A
authors.initials: CA
authors.lastname: Merrifield
authors.affiliation: Section of Biomolecular Medicine, Division of Computational and Systems Medicine, Faculty of Medicine, Imperial College London, UK.
authors.forename: E
authors.initials: E
authors.lastname: Holmes
authors.affiliation: Department of Gastroenterology, School of Veterinary Medicine, University of Liverpool, Neston, UK.
authors.forename: C J
authors.initials: CJ
authors.lastname: Proudman
authors.affiliation: Department of Food and Nutritional Sciences, University of Reading, Berkshire, UK.
authors.forename: J R
authors.initials: JR
authors.lastname: Swann
mesh_terms: D000818:Animals; D001826:Body Fluids / Q000737:chemistry*; D005243:Feces / Q000737:chemistry*; D006736:Horses / Q000097:blood / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D055442:Metabolome; D055432:Metabolomics / Q000379:methods; D014556:Urine / Q000737:chemistry*
keywords: biofluids; horse; metabolites; metabolomics; metabonomics; nuclear magnetic resonance