title: Increased gut microbiota diversity and abundance of Faecalibacterium prausnitzii and Akkermansia after fasting: a pilot study.
abstract: BACKGROUND
  An impaired gut microbiota has been reported as an important factor in the pathogenesis of obesity. Weight reduction has already been mentioned to improve gut microbial subpopulations involved in inflammatory processes, though other subpopulations still need further investigation. Thus, weight reduction in the context of a fasting program together with a probiotic intervention may improve the abundance and diversity of gut microbiota.
  
  
  METHODS
  In this pilot study, overweight people underwent a fasting program with laxative treatment for 1 week followed by a 6 week intervention with a probiotic formula. Gut microbiota were analyzed on the basis of 16s rDNA with a quantitative real time polymerase chain reaction. Additionally, a food frequency questionnaire with questions about nutritional behavior, lifestyle, and physical activity was administered before and after the intervention.
  
  
  RESULTS
  We observed an increase in microbial diversity over the study period. No significant changes in abundance of total bacteria, or of Bacteroidetes, Prevotella, Clostridium cluster XIVa, or Clostridium cluster IV were found, although Faecalibacterium prausnitzii showed an increase over the study period. In addition, Akkermanisa and Bifidobacteria increased in abundance due to intervention. The inflammation-associated gut microbes Enterobacteria and Lactobacilli increased during the first week and then declined by the end of the intervention. Two-thirds of the study participants harbored Archaea. No significant improvements of eating habits were reported, although physical activity improved due to the intervention.
  
  
  CONCLUSIONS
  Our results show that caloric restriction affects gut microbiota by proliferating mucin-degrading microbial subpopulations. An additional intervention with a probiotic formula increased probiotic-administered gut microbial populations.
authors.affiliation: Institute of Nutritional Sciences, University Vienna, Althahnstraße 14, 1090, Vienna, Austria, marlene.remely@univie.ac.at.
authors.forename: Marlene
authors.initials: M
authors.lastname: Remely
authors.forename: Berit
authors.initials: B
authors.lastname: Hippe
authors.forename: Isabella
authors.initials: I
authors.lastname: Geretschlaeger
authors.forename: Sonja
authors.initials: S
authors.lastname: Stegmayer
authors.forename: Ingrid
authors.initials: I
authors.lastname: Hoefinger
authors.forename: Alexander
authors.initials: A
authors.lastname: Haslberger
mesh_terms: D058491:Bacterial Load; D000068016:Eubacteriales / Q000254:growth & development*; D005215:Fasting / Q000502:physiology*; D005243:Feces / Q000382:microbiology; D005260:Female; D000069196:Gastrointestinal Microbiome / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000382:microbiology / Q000628:therapy*; D010865:Pilot Projects; D019936:Probiotics / Q000008:administration & dosage; D061327:Verrucomicrobia / Q000254:growth & development*