title: Decreased abundance of Faecalibacterium prausnitzii in the gut microbiota of Crohn's disease.
abstract: OBJECTIVE
  Dysbiosis is thought to be relevant to the etiology and pathogenesis of Crohn's disease (CD). In this study, we investigated the abundance of Faecalibacterium prausnitzii, as well as Bilophila wadsworthia, in the gut microbiota of Japanese CD patients.
  
  
  METHODS
  Forty-seven CD patients and 20 healthy controls were enrolled. Abundance of F. prausnitzii in fecal samples was quantified by real-time polymerase chain reaction. The gut microbiota profile was evaluated by terminal restriction fragment length polymorphisms.
  
  
  RESULTS
  The abundance of F. prausnitzii significantly decreased in CD patients compared with healthy subjects. B. wadsworthia was scarcely detected in the same samples. Among CD patients, the Crohn's Disease Activity Index, C-reactive protein levels, and erythrocyte sedimentation rate were significantly lower, and serum albumin levels were significantly higher in the high F. prausnitzii group compared with the low group. Terminal restriction fragment length polymorphisms analysis showed that fecal bacterial communities of CD patients differed from those of healthy individuals. The changes in simulated bacterial composition indicated that class Clostridia, including genus Faecalibacterium, was significantly less abundant in CD patients as compared with healthy individuals. The bacterial diversity measured by the Shannon Diversity Index was significantly reduced in CD patients compared with healthy individuals.
  
  
  CONCLUSIONS
  The decreased abundance of class Clostridia, including F. prausnitzii, may translate into a reduction of commensal bacteria-mediated, anti-inflammatory activities in the mucosa, which are relevant to the pathophysiology of CD. In contrast, the role of B. wadsworthia was suspected to be minimal.
authors.affiliation: Division of Mucosal Immunology, Graduate School, Shiga University of Medical Science, Otsu, Japan.
authors.forename: Takehide
authors.initials: T
authors.lastname: Fujimoto
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Imaeda
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Takahashi
authors.forename: Eiji
authors.initials: E
authors.lastname: Kasumi
authors.forename: Shigeki
authors.initials: S
authors.lastname: Bamba
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Fujiyama
authors.forename: Akira
authors.initials: A
authors.lastname: Andoh
mesh_terms: D000328:Adult; D045282:Bilophila / Q000302:isolation & purification*; D016022:Case-Control Studies; D003013:Clostridium / Q000502:physiology*; D003424:Crohn Disease / Q000382:microbiology*; D017931:DNA Primers / Q000737:chemistry; D004269:DNA, Bacterial / Q000032:analysis; D005243:Feces / Q000382:microbiology; D005260:Female; D041981:Gastrointestinal Tract / Q000382:microbiology*; D006801:Humans; D008297:Male; D054892:Metagenome; D008875:Middle Aged; D012150:Polymorphism, Restriction Fragment Length; D060888:Real-Time Polymerase Chain Reaction; D012720:Severity of Illness Index
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial