Increased Prevalence of Methanosphaera stadtmanae in Inflammatory Bowel Diseases

• Published in: PloS one Vol. 9; no. 2; p. e87734
• Main Authors: Blais Lecours, Pascale, Marsolais, David, Cormier, Yvon, Berberi, Marie, Haché, Chantal, Bourdages, Raymond, Duchaine, Caroline
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 03.02.2014; Public Library of Science (PLoS)
• Subjects: Adult; Antibiotics; Antigens; Archaea; Bacteria; Biodiversity; Biology; Blotting, Western; Canada - epidemiology; Case-Control Studies; Crohn's disease; Crohns disease; Cytokines - blood; Cytokines - genetics; Deoxyribonucleic acid; Development and progression; Digestive system; Diseases; DNA; DNA, Bacterial - genetics; E coli; Enzyme-Linked Immunosorbent Assay; Escherichia coli; Etiology; Feces - microbiology; Female; Gastrointestinal Tract - microbiology; Humans; Immune response; Immune system; Immunity; Immunogenicity; Immunoglobulin G; Inflammatory bowel disease; Inflammatory bowel diseases; Inflammatory Bowel Diseases - epidemiology; Inflammatory Bowel Diseases - microbiology; Inflammatory response; Intestinal microflora; Intestine; Leukocytes (mononuclear); Lungs; Male; Medical research; Medicine; Methanobacteriaceae - classification; Methanobacteriaceae - genetics; Methanobacteriaceae - isolation & purification; Methanogenic bacteria; Microbiota; Microbiota (Symbiotic organisms); Microorganisms; Mortgage backed securities; Mucosal immunity; Patients; Peripheral blood mononuclear cells; Prevalence; Real-Time Polymerase Chain Reaction; Tumor necrosis factor; Canada
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0087734

The gut microbiota is associated with the modulation of mucosal immunity and the etiology of inflammatory bowel diseases (IBD). Previous studies focused on the impact of bacterial species on IBD but seldom suspected archaea, which can be a major constituent of intestinal microbiota, to be implicated in the diseases. Recent evidence supports that two main archaeal species found in the digestive system of humans, Methanobrevibacter smithii (MBS) and Methanosphaera stadtmanae (MSS) can have differential immunogenic properties in lungs of mice; with MSS but not MBS being a strong inducer of the inflammatory response. We thus aimed at documenting the immunogenic potential of MBS and MSS in humans and to explore their association with IBD. To validate the immunogenicity of MBS and MSS in humans, peripheral blood mononuclear cells from healthy subjects were stimulated with these two microorganisms and the production of inflammatory cytokine TNF was measured by ELISA. To verify MBS and MSS prevalence in IBD, stool samples from 29 healthy control subjects and 29 patients suffering from IBD were collected for DNA extraction. Plasma was also collected from these subjects to measure antigen-specific IgGs by ELISA. Quantitative PCR was used for bacteria, methanogens, MBS and MSS quantification. Mononuclear cells stimulated with MSS produced higher concentrations of TNF (39.5 ng/ml) compared to MBS stimulation (9.1 ng/ml). Bacterial concentrations and frequency of MBS-containing stools were similar in both groups. However, the number of stool samples positive for the inflammatory archaea MSS was higher in patients than in controls (47% vs 20%). Importantly, only IBD patients developed a significant anti-MSS IgG response. The prevalence of MSS is increased in IBD patients and is associated with an antigen-specific IgG response.