title: Reduction of butyrate- and methane-producing microorganisms in patients with Irritable Bowel Syndrome.
abstract: The pathophysiology of irritable bowel syndrome (IBS) remains unclear. Here we investigated the microbiome of a large cohort of patients to identify specific signatures for IBS subtypes. We examined the microbiome of 113 patients with IBS and 66 healthy controls. A subset of these participants provided two samples one month apart. We analyzed a total of 273 fecal samples, generating more than 20 million 16S rRNA sequences. In patients with IBS, a significantly lower microbial diversity was associated with a lower relative abundance of butyrate-producing bacteria (P = 0.002; q < 0.06), in particular in patients with IBS-D and IBS-M. IBS patients who did not receive any treatment harboured a lower abundance of Methanobacteria compared to healthy controls (P = 0.005; q = 0.05). Furthermore, significant correlations were observed between several bacterial taxa and sensation of flatulence and abdominal pain (P < 0.05). Altogether, our findings showed that IBS-M and IBS-D patients are characterized by a reduction of butyrate producing bacteria, known to improve intestinal barrier function, and a reduction of methane producing microorganisms a major mechanism of hydrogen disposal in the human colon, which could explain excess of abdominal gas in IBS.
authors.affiliation: Digestive System Research Unit, Vall d'Hebron Research Institute, Passeig Vall d'Hebron 119-129, Barcelona 08035, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Pozuelo
authors.affiliation: Digestive System Research Unit, Vall d'Hebron Research Institute, Passeig Vall d'Hebron 119-129, Barcelona 08035, Spain.
authors.forename: Suchita
authors.initials: S
authors.lastname: Panda
authors.affiliation: Digestive System Research Unit, Vall d'Hebron Research Institute, Passeig Vall d'Hebron 119-129, Barcelona 08035, Spain.
authors.forename: Alba
authors.initials: A
authors.lastname: Santiago
authors.affiliation: Digestive Unit, University Hospital Vall d'Hebron, Passeig Vall d'Hebron 119-129, Barcelona 08035, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Mendez
authors.affiliation: 1] Digestive Unit, University Hospital Vall d'Hebron, Passeig Vall d'Hebron 119-129, Barcelona 08035, Spain [2] Centro de Investigacion Biomedica en Red en el Área tematica de Enfermedades Heptaticas y Digestivas, CIBERehd, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Anna
authors.initials: A
authors.lastname: Accarino
authors.affiliation: 1] Digestive System Research Unit, Vall d'Hebron Research Institute, Passeig Vall d'Hebron 119-129, Barcelona 08035, Spain [2] Digestive Unit, University Hospital Vall d'Hebron, Passeig Vall d'Hebron 119-129, Barcelona 08035, Spain [3] Centro de Investigacion Biomedica en Red en el Área tematica de Enfermedades Heptaticas y Digestivas, CIBERehd, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Santos
authors.affiliation: 1] Digestive System Research Unit, Vall d'Hebron Research Institute, Passeig Vall d'Hebron 119-129, Barcelona 08035, Spain [2] Digestive Unit, University Hospital Vall d'Hebron, Passeig Vall d'Hebron 119-129, Barcelona 08035, Spain [3] Centro de Investigacion Biomedica en Red en el Área tematica de Enfermedades Heptaticas y Digestivas, CIBERehd, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Guarner
authors.affiliation: 1] Digestive System Research Unit, Vall d'Hebron Research Institute, Passeig Vall d'Hebron 119-129, Barcelona 08035, Spain [2] Digestive Unit, University Hospital Vall d'Hebron, Passeig Vall d'Hebron 119-129, Barcelona 08035, Spain [3] Centro de Investigacion Biomedica en Red en el Área tematica de Enfermedades Heptaticas y Digestivas, CIBERehd, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Azpiroz
authors.affiliation: 1] Digestive System Research Unit, Vall d'Hebron Research Institute, Passeig Vall d'Hebron 119-129, Barcelona 08035, Spain [2] Centro de Investigacion Biomedica en Red en el Área tematica de Enfermedades Heptaticas y Digestivas, CIBERehd, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Chaysavanh
authors.initials: C
authors.lastname: Manichanh
mesh_terms: D015746:Abdominal Pain / Q000382:microbiology* / Q000473:pathology / Q000503:physiopathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001439:Bacteroides / Q000145:classification / Q000235:genetics / Q000378:metabolism; D002087:Butyrates / Q000378:metabolism*; D016022:Case-Control Studies; D019605:Euryarchaeota / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D005243:Feces / Q000382:microbiology; D005260:Female; D000068536:Bacillota / Q000145:classification / Q000235:genetics / Q000378:metabolism; D005414:Flatulence / Q000382:microbiology* / Q000473:pathology / Q000503:physiopathology; D014644:Genetic Variation; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000382:microbiology* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008697:Methane / Q000096:biosynthesis*; D064307:Microbiota / Q000235:genetics; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D002087:Butyrates; D012336:RNA, Ribosomal, 16S; D008697:Methane