title: No difference in small bowel microbiota between patients with irritable bowel syndrome and healthy controls.
abstract: Several studies have indicated that colonic microbiota may exhibit important differences between patients with irritable bowel syndrome (IBS) and healthy controls. Less is known about the microbiota of the small bowel. We used massive parallel sequencing to explore the composition of small bowel mucosa-associated microbiota in patients with IBS and healthy controls. We analysed capsule biopsies from the jejunum of 35 patients (26 females) with IBS aged 18-(36)-57 years and 16 healthy volunteers (11 females) aged 20-(32)-48 years. Sequences were analysed based on taxonomic classification. The phyla with the highest total abundance across all samples were: Firmicutes (43%), Proteobacteria (23%), Bacteroidetes (15%), Actinobacteria (9.3%) and Fusobacteria (7.0%). The most abundant genera were: Streptococcus (19%), Veillonella (13%), Prevotella (12%), Rothia (6.4%), Haemophilus (5.7%), Actinobacillus (5.5%), Escherichia (4.6%) and Fusobacterium (4.3%). We found no difference among major phyla or genera between patients with IBS and controls. We identified a cluster of samples in the small bowel microbiota dominated by Prevotella, which may represent a common enterotype of the upper small intestine. The remaining samples formed a gradient, dominated by Streptococcus at one end and Escherichia at the other.
authors: Karolinska Institutet, Department of Medicine and Center for Digestive Diseases, Karolinska University Hospital Huddinge, Stockholm, Sweden.
authors: Aldona
authors: A
authors: Dlugosz
authors: Karolinska Institutet, Department of Medical Epidemiology and Biostatistics, Stockholm, Sweden.
authors: Björn
authors: B
authors: Winckler
authors: Stockholm University, Department of Biochemistry and Biophysics, Stockholm, Sweden.
authors: Elin
authors: E
authors: Lundin
authors: Public Health Agency of Sweden, Unit for Laboratory Surveillance of Vaccine Preventable Diseases, Solna, Sweden.
authors: Katherina
authors: K
authors: Zakikhany
authors: Karolinska Institutet, Department of Laboratory Medicine, Stockholm, Sweden.
authors: Gunnar
authors: G
authors: Sandström
authors: Karolinska Institutet, Department of Medical Epidemiology and Biostatistics, Stockholm, Sweden.
authors: Weimin
authors: W
authors: Ye
authors: Karolinska Institutet, Department of Microbiology, Tumor &Cell Biology and Science for Life Laboratory, Stockholm, Sweden.
authors: Lars
authors: L
authors: Engstrand
authors: Karolinska Institutet, Department of Medicine and Center for Digestive Diseases, Karolinska University Hospital Huddinge, Stockholm, Sweden.
authors: Greger
authors: G
authors: Lindberg
mesh_terms: D000293:Adolescent; D000328:Adult; D044822:Biodiversity; D016022:Case-Control Studies; D016000:Cluster Analysis; D005260:Female; D006801:Humans; D007421:Intestine, Small / Q000382:microbiology*; D043183:Irritable Bowel Syndrome / Q000209:etiology*; D008297:Male; D054892:Metagenome; D064307:Microbiota; D008875:Middle Aged; D025341:Principal Component Analysis; D055815:Young Adult