title: Low counts of Faecalibacterium prausnitzii in colitis microbiota.
abstract: BACKGROUND
  The intestinal microbiota is suspected to play a role in colitis and particularly in inflammatory bowel disease (IBD) pathogenesis. The aim was to compare the fecal microbiota composition of patients with colitis to that of healthy subjects (HS).
  
  
  METHODS
  fecal samples from 22 active Crohn's disease (A-CD) patients, 10 CD patients in remission (R-CD), 13 active ulcerative colitis (A-UC) patients, 4 UC patients in remission (R-UC), 8 infectious colitis (IC) patients, and 27 HS were analyzed by quantitative real-time polymerase chain reaction (PCR) targeting the 16S rRNA gene. Bacterial counts were transformed to logarithms (Log(10) CFU) for statistical analysis.
  
  
  RESULTS
  Bacteria of the phylum Firmicutes (Clostridium leptum and Clostridium coccoides groups) were less represented in A-IBD patients (9.7; P = 0.004) and IC (9.4; P = 0.02), compared to HS (10.8). Faecalibacterium prausnitzii species (a major representative of the C. leptum group) had lower counts in A-IBD and IC patients compared to HS (8.8 and 8.3 versus 10.4; P = 0.0004 and P = 0.003). The Firmicutes/Bacteroidetes ratio was lower in A-IBD (1.3; P = 0.0001) and IC patients (0.4; P = 0.002). Compared to HS, Bifidobacteria were less represented in A-IBD and IC (7.9 and 7.7 versus 9.2; P = 0.001 and P = 0.01).
  
  
  CONCLUSIONS
  The fecal microbiota of patients with IBD differs from that of HS. The phylum Firmicutes and particularly the species F. prausnitzii, are underrepresented in A-IBD patients as well as in IC patients. These bacteria could be crucial to gut homeostasis since lower counts of F. prausnitzii are consistently associated with a reduced protection of the gut mucosa.
authors.affiliation: UEPSD, INRA, Jouy-en-Josas, France. sokol_harry@yahoo.fr
authors.forename: H
authors.initials: H
authors.lastname: Sokol
authors.forename: P
authors.initials: P
authors.lastname: Seksik
authors.forename: J P
authors.initials: JP
authors.lastname: Furet
authors.forename: O
authors.initials: O
authors.lastname: Firmesse
authors.forename: I
authors.initials: I
authors.lastname: Nion-Larmurier
authors.forename: L
authors.initials: L
authors.lastname: Beaugerie
authors.forename: J
authors.initials: J
authors.lastname: Cosnes
authors.forename: G
authors.initials: G
authors.lastname: Corthier
authors.forename: P
authors.initials: P
authors.lastname: Marteau
authors.forename: J
authors.initials: J
authors.lastname: Doré
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000382:microbiology* / Q000473:pathology; D003106:Colon / Q000382:microbiology / Q000473:pathology; D015169:Colony Count, Microbial; D003424:Crohn Disease / Q000382:microbiology* / Q000473:pathology; D004269:DNA, Bacterial / Q000235:genetics; D005243:Feces / Q000737:chemistry / Q000382:microbiology*; D005260:Female; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology* / Q000473:pathology; D006801:Humans; D008297:Male; D012074:Remission Induction; D045857:Ruminococcus / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D004269:DNA, Bacterial