title: Increase in fecal primary bile acids and dysbiosis in patients with diarrhea-predominant irritable bowel syndrome.
abstract: BACKGROUND
  Irritable bowel syndrome (IBS) is a multifactorial disease for which a dysbiosis of the gut microbiota has been described. Bile acids (BA) could play a role as they are endogenous laxatives and are metabolized by gut microbiota. We compared fecal BA profiles and microbiota in healthy subjects (HS) and patients with diarrhea-predominant IBS (IBS-D), and we searched for an association with symptoms.
  
  
  METHODS
  Clinical features and stool samples were collected in IBS-D patients and HS. Fecal BA profiles were generated using HPLC coupled to tandem mass spectrometry. The fecal microbiota composition was assessed by q-PCR targeting dominant bacterial groups and species implicated in BA transformation.
  
  
  RESULTS
  Fourteen IBS-D patients and 18 HS were included. The two groups were comparable in terms of age and sex. The percentage of fecal primary BA was significantly higher in IBS-D patients than in HS, and it was significantly correlated with stool consistency and frequency. Fecal counts of all bacteria, lactobacillus, coccoides, leptum and Faecalibacterium prausnitzii were similar. There was a significant increase of Escherichia coli and a significant decrease of leptum and bifidobacterium in IBS-D patients.
  
  
  CONCLUSIONS
  We report an increase of primary BA in the feces of IBS-D patients compared to HS, correlated with stool consistency and frequency. A dysbiosis of different bacterial groups was detected, some of them involved in BA transformation. As the gut microbiota is the exclusive pathway to transform primary into secondary BA, this suggests a functional consequence of dysbiosis, leading to lower BA transformation.
authors.affiliation: Hepato Gastro Enterology Department, Louis Mourier Hospital, University Paris VII, AP-HP, Colombes, France. henri.duboc@gmail.com
authors.forename: H
authors.initials: H
authors.lastname: Duboc
authors.forename: D
authors.initials: D
authors.lastname: Rainteau
authors.forename: S
authors.initials: S
authors.lastname: Rajca
authors.forename: L
authors.initials: L
authors.lastname: Humbert
authors.forename: D
authors.initials: D
authors.lastname: Farabos
authors.forename: M
authors.initials: M
authors.lastname: Maubert
authors.forename: V
authors.initials: V
authors.lastname: Grondin
authors.forename: P
authors.initials: P
authors.lastname: Jouet
authors.forename: D
authors.initials: D
authors.lastname: Bouhassira
authors.forename: P
authors.initials: P
authors.lastname: Seksik
authors.forename: H
authors.initials: H
authors.lastname: Sokol
authors.forename: B
authors.initials: B
authors.lastname: Coffin
authors.forename: J M
authors.initials: JM
authors.lastname: Sabaté
mesh_terms: D000328:Adult; D001647:Bile Acids and Salts / Q000032:analysis*; D003106:Colon / Q000382:microbiology; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D003967:Diarrhea / Q000235:genetics / Q000382:microbiology*; D005243:Feces / Q000737:chemistry* / Q000382:microbiology; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000382:microbiology; D043183:Irritable Bowel Syndrome / Q000235:genetics / Q000382:microbiology*; D008297:Male; D054892:Metagenome / Q000235:genetics; D008875:Middle Aged
chemical_list: D001647:Bile Acids and Salts; D004269:DNA, Bacterial