title: Smoking cessation induces profound changes in the composition of the intestinal microbiota in humans.
abstract: BACKGROUND
  The human intestinal microbiota is a crucial factor in the pathogenesis of various diseases, such as metabolic syndrome or inflammatory bowel disease (IBD). Yet, knowledge about the role of environmental factors such as smoking (which is known to influence theses aforementioned disease states) on the complex microbial composition is sparse. We aimed to investigate the role of smoking cessation on intestinal microbial composition in 10 healthy smoking subjects undergoing controlled smoking cessation.
  
  
  METHODS
  During the observational period of 9 weeks repetitive stool samples were collected. Based on abundance of 16S rRNA genes bacterial composition was analysed and compared to 10 control subjects (5 continuing smokers and 5 non-smokers) by means of Terminal Restriction Fragment Length Polymorphism analysis and high-throughput sequencing.
  
  
  RESULTS
  Profound shifts in the microbial composition after smoking cessation were observed with an increase of Firmicutes and Actinobacteria and a lower proportion of Bacteroidetes and Proteobacteria on the phylum level. In addition, after smoking cessation there was an increase in microbial diversity.
  
  
  CONCLUSIONS
  These results indicate that smoking is an environmental factor modulating the composition of human gut microbiota. The observed changes after smoking cessation revealed to be similar to the previously reported differences in obese compared to lean humans and mice respectively, suggesting a potential pathogenetic link between weight gain and smoking cessation. In addition they give rise to a potential association of smoking status and the course of IBD.
authors.affiliation: Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Luc
authors.initials: L
authors.lastname: Biedermann
authors.forename: Jonas
authors.initials: J
authors.lastname: Zeitz
authors.forename: Jessica
authors.initials: J
authors.lastname: Mwinyi
authors.forename: Eveline
authors.initials: E
authors.lastname: Sutter-Minder
authors.forename: Ateequr
authors.initials: A
authors.lastname: Rehman
authors.forename: Stephan J
authors.initials: SJ
authors.lastname: Ott
authors.forename: Claudia
authors.initials: C
authors.lastname: Steurer-Stey
authors.forename: Anja
authors.initials: A
authors.lastname: Frei
authors.forename: Pascal
authors.initials: P
authors.lastname: Frei
authors.forename: Michael
authors.initials: M
authors.lastname: Scharl
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Loessner
authors.forename: Stephan R
authors.initials: SR
authors.lastname: Vavricka
authors.forename: Michael
authors.initials: M
authors.lastname: Fried
authors.forename: Stefan
authors.initials: S
authors.lastname: Schreiber
authors.forename: Markus
authors.initials: M
authors.lastname: Schuppler
authors.forename: Gerhard
authors.initials: G
authors.lastname: Rogler
mesh_terms: D000293:Adolescent; D000328:Adult; D001835:Body Weight / Q000502:physiology; D002149:Energy Intake / Q000502:physiology; D005260:Female; D006801:Humans; D007422:Intestines / Q000382:microbiology*; D008297:Male; D054892:Metagenome / Q000502:physiology*; D008875:Middle Aged; D010802:Phylogeny; D025341:Principal Component Analysis; D016540:Smoking Cessation; D055815:Young Adult