title: Effects of bowel cleansing on the intestinal microbiota.
abstract: OBJECTIVE
  An adequate bowel cleansing is essential for a successful colonoscopy. Although purgative consumption is safe for the patient, there is little consensus on how the intestinal microbiota is affected by the procedure, especially regarding the potential long-term consequences.
  
  
  METHODS
  23 healthy subjects were randomised into two study groups consuming a bowel preparation (Moviprep), either in two separate doses of 1 L or as a single 2-L dose. Participants donated faecal samples at the baseline, after bowel cleansing, 14 and 28 days after the treatment. The intestinal microbiota composition was determined with phylogenetic microarray as well as quantitative PCR analysis and correlated with the previously quantified faecal serine proteases.
  
  
  RESULTS
  The lavage introduced an instant and substantial change to the intestinal microbiota. The total microbial load was decreased by 31-fold and 22% of the participants lost the subject-specificity of their microbiota. While the bacterial levels and community composition were essentially restored within 14 days, the rate of recovery was dose dependent: consumption of the purgative in a single dose had a more severe effect on the microbiota composition than that of a double dose, and notably increased the levels of Proteobacteria, Fusobacteria and bacteria related to Dorea formicigenerans. The abundance of the latter also correlated with the amount of faecal serine proteases that were increased after purging.
  
  
  CONCLUSIONS
  Our results suggest that the bowel cleansing using two separate dosages introduces fewer alterations to the intestinal microbiota than a single dose and hence may be preferred in clinical practice.
authors.affiliation: Department of Veterinary Biosciences, Microbiology, University of Helsinki, Helsinki, Finland.
authors.forename: Jonna
authors.initials: J
authors.lastname: Jalanka
authors.affiliation: Immune Biology Research Program, Department of Bacteriology and Immunology, University of Helsinki, Helsinki, Finland.
authors.forename: Anne
authors.initials: A
authors.lastname: Salonen
authors.affiliation: Department of Veterinary Biosciences, Microbiology, University of Helsinki, Helsinki, Finland.
authors.forename: Jarkko
authors.initials: J
authors.lastname: Salojärvi
authors.affiliation: Department of Veterinary Biosciences, Microbiology, University of Helsinki, Helsinki, Finland.
authors.forename: Jarmo
authors.initials: J
authors.lastname: Ritari
authors.affiliation: Department of Veterinary Biosciences, Microbiology, University of Helsinki, Helsinki, Finland.
authors.forename: Outi
authors.initials: O
authors.lastname: Immonen
authors.affiliation: NIHR Biomedical Research Unit, Nottingham Digestive Diseases Centre, University Hospital, Nottingham, UK.
authors.forename: Luca
authors.initials: L
authors.lastname: Marciani
authors.affiliation: Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, UK.
authors.forename: Penny
authors.initials: P
authors.lastname: Gowland
authors.affiliation: Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, UK.
authors.forename: Caroline
authors.initials: C
authors.lastname: Hoad
authors.affiliation: NIHR Biomedical Research Unit, Nottingham Digestive Diseases Centre, University Hospital, Nottingham, UK.
authors.forename: Klara
authors.initials: K
authors.lastname: Garsed
authors.affiliation: NIHR Biomedical Research Unit, Nottingham Digestive Diseases Centre, University Hospital, Nottingham, UK.
authors.forename: Ching
authors.initials: C
authors.lastname: Lam
authors.affiliation: Department of Veterinary Biosciences, Microbiology, University of Helsinki, Helsinki, Finland.
authors.forename: Airi
authors.initials: A
authors.lastname: Palva
authors.affiliation: NIHR Biomedical Research Unit, Nottingham Digestive Diseases Centre, University Hospital, Nottingham, UK.
authors.forename: Robin C
authors.initials: RC
authors.lastname: Spiller
authors.affiliation: Department of Veterinary Biosciences, Microbiology, University of Helsinki, Helsinki, Finland Immune Biology Research Program, Department of Bacteriology and Immunology, University of Helsinki, Helsinki, Finland Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands.
authors.forename: Willem M
authors.initials: WM
authors.lastname: de Vos
mesh_terms: D001419:Bacteria / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D003106:Colon / Q000382:microbiology*; D003113:Colonoscopy / Q000379:methods; D004305:Dose-Response Relationship, Drug; D005243:Feces / Q000382:microbiology; D005500:Follow-Up Studies; D000069196:Gastrointestinal Microbiome / Q000187:drug effects*; D064368:Healthy Volunteers; D006801:Humans; D007413:Intestinal Mucosa / Q000382:microbiology*; D011092:Polyethylene Glycols / Q000008:administration & dosage*; D012329:RNA, Bacterial / Q000032:analysis; D007507:Therapeutic Irrigation
chemical_list: C520497:MoviPrep; D012329:RNA, Bacterial; D011092:Polyethylene Glycols
keywords: COLONIC BACTERIA; COLONIC MICROFLORA; COLONOSCOPY; GASTROINTESINAL ENDOSCOPY; INTESTINAL BACTERIA