title: Interplay between bile acid metabolism and microbiota in irritable bowel syndrome.
abstract: BACKGROUND
  Irritable bowel syndrome (IBS) physiopathology is multifactorial and roles for both microbiota and bile acid (BA) modifications have been proposed. We investigated role of dysbiosis, transit pattern and BA metabolism in IBS.
  
  
  METHODS
  Clinical data, serum, and stool samples were collected in 15 healthy subjects (HS), 16 diarrhea-predominant (IBS-D) and 15 constipation-predominant IBS (IBS-C). Fecal microbiota composition was analyzed by real-time PCR. Sera and fecal BA profiles, 7α-C4 levels, and in vitro BA transformation activity by fecal microbiota were measured by mass spectrometry. Serum Fibroblast Growth Factor 19 (FGF19) was assayed by ELISA.
  Dysbiosis was present in IBS patients with an increase in Escherichia coli in IBS-D patients (p = 0.03), and an increase in Bacteroides (p = 0.01) and Bifidobacterium (p = 0.04) in IBS-C patients. Sera primary and amino-conjugated BA were increased in IBS-D (63.5 ± 5.5%, p = 0.01 and 78.9 ± 6.3%, p = 0.03) and IBS-C patients (55.9 ± 5.5%, p = 0.04 and 65.3 ± 6.5%, p = 0.005) compared to HS (37.0 ± 5.8% and 56.7 ± 8.1%). Serum 7α-C4 and FGF19 levels were not different among all three groups. Fecal primary BA were increased in IBS-D patients compared to HS, including chenodeoxycholic acid which has laxative properties (25.6 ± 8.5% vs 3.5 ± 0.6%, p = 0.005). Bile acid deconjugation activity was decreased in IBS-D (p = 0.0001) and IBS-C (p = 0.003) feces. Abdominal pain was positively correlated with serum (R = 0.635, p < 0.001) and fecal (R = 0.391, p = 0.024) primary BA.
  
  
  CONCLUSIONS
  Different sera and fecal BA profiles in IBS patients could be secondary to dysbiosis and further differences between IBS-C and IBS-D could explain stool patterns. This study opens new fields in IBS physiopathology and suggests that modification of BA profiles could have therapeutic potential.
authors.affiliation: ERL U1157/UMR 7203. Inserm, Paris VI University, Paris, France.|Department of Gastroenterology, Louis Mourier Hospital, AP-HP, Colombes, France.
authors.forename: M
authors.initials: M
authors.lastname: Dior
authors.affiliation: ERL U1157/UMR 7203. Inserm, Paris VI University, Paris, France.
authors.forename: H
authors.initials: H
authors.lastname: Delagrèverie
authors.affiliation: ERL U1157/UMR 7203. Inserm, Paris VI University, Paris, France.|Department of Gastroenterology, Louis Mourier Hospital, AP-HP, Colombes, France.
authors.forename: H
authors.initials: H
authors.lastname: Duboc
authors.affiliation: Department of Gastroenterology, Louis Mourier Hospital, AP-HP, Colombes, France.|Inserm U987 Physiopathologie et pharmacologie Clinique de la douleur, Hôpital Ambroise Paré, AP-HP, Boulogne, France.
authors.forename: P
authors.initials: P
authors.lastname: Jouet
authors.affiliation: Department of Gastroenterology, Louis Mourier Hospital, AP-HP, Colombes, France.|Inserm U987 Physiopathologie et pharmacologie Clinique de la douleur, Hôpital Ambroise Paré, AP-HP, Boulogne, France.
authors.forename: B
authors.initials: B
authors.lastname: Coffin
authors.affiliation: ERL U1157/UMR 7203. Inserm, Paris VI University, Paris, France.
authors.forename: L
authors.initials: L
authors.lastname: Brot
authors.affiliation: ERL U1157/UMR 7203. Inserm, Paris VI University, Paris, France.
authors.forename: L
authors.initials: L
authors.lastname: Humbert
authors.affiliation: ERL U1157/UMR 7203. Inserm, Paris VI University, Paris, France.
authors.forename: G
authors.initials: G
authors.lastname: Trugnan
authors.affiliation: ERL U1157/UMR 7203. Inserm, Paris VI University, Paris, France.|Department of Gastroenterology and Nutrition, Saint Antoine Hospital, AP-HP, Paris, France.
authors.forename: P
authors.initials: P
authors.lastname: Seksik
authors.affiliation: ERL U1157/UMR 7203. Inserm, Paris VI University, Paris, France.|Department of Gastroenterology and Nutrition, Saint Antoine Hospital, AP-HP, Paris, France.|INRA, UMR1319 Micalis, Jouy-en-Josas, France.
authors.forename: H
authors.initials: H
authors.lastname: Sokol
authors.affiliation: ERL U1157/UMR 7203. Inserm, Paris VI University, Paris, France.|Biochemistry Department, Saint Antoine Hospital, AP-HP, Paris, France.
authors.forename: D
authors.initials: D
authors.lastname: Rainteau
authors.affiliation: Department of Gastroenterology, Louis Mourier Hospital, AP-HP, Colombes, France.|Inserm U987 Physiopathologie et pharmacologie Clinique de la douleur, Hôpital Ambroise Paré, AP-HP, Boulogne, France.
authors.forename: J-M
authors.initials: JM
authors.lastname: Sabate
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001647:Bile Acids and Salts / Q000032:analysis / Q000378:metabolism*; D005243:Feces / Q000737:chemistry* / Q000382:microbiology*; D005260:Female; D000069196:Gastrointestinal Microbiome / Q000502:physiology*; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000378:metabolism* / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D001647:Bile Acids and Salts
keywords: bile acid metabolism; irritable bowel syndrome; microbiota; neurogastroenterology