title: Fecal Microbiota in Patients with Irritable Bowel Syndrome Compared with Healthy Controls Using Real-Time Polymerase Chain Reaction: An Evidence of Dysbiosis.
abstract: BACKGROUND
  Dysbiosis may play a role in irritable bowel syndrome (IBS), hitherto an enigmatic disorder. We evaluated selected fecal microbes in IBS patients and healthy controls (HC).
  
  
  METHODS
  Fecal 16S rRNA copy number of selected bacteria was studied using qPCR in 47 patients with IBS (Rome III) and 30 HC.
  
  
  RESULTS
  Of 47 patients, 20 had constipation (IBS-C), 20 diarrhea (IBS-D), and seven unclassified IBS (IBS-U). Relative difference in 16S rRNA copy number of Bifidobacterium (P = 0.042) was lower, while those of Ruminococcus productus-Clostridium coccoides (P = 0.016), Veillonella (P = 0.008), Bacteroides thetaiotamicron (P < 0.001), Pseudomonas aeruginosa (P < 0.001), and Gram-negative bacteria (GNB, P = 0.001) were higher among IBS patients than HC. Number of Lactobacillus (P = 0.002) was lower, while that of Bacteroides thetaiotamicron (P < 0.001) and segmented filamentous bacteria (SFB, P < 0.001) was higher among IBS-D than IBS-C. Numbers of Bacteroides thetaiotamicron (P < 0.001), P. aeruginosa (P < 0.001), and GNB (P < 0.01) were higher among IBS-C and IBS-D than HC. Quantity of SFB was higher among IBS-D (P = 0.011) and lower among IBS-C (P = 0.002) than HC. Number of Veillonella species was higher among IBS-C than HC (P = 0.002). P. aeruginosa was frequently detected among IBS than HC (46/47 [97.9 %] vs. 10/30 [33.3 %], P < 0.001). Abdominal distension (n = 34/47) was associated with higher number of Bacteroides thetaiotamicron, Clostridium coccoides, P. aeruginosa, SFB, and GNB; bloating (n = 22/47) was associated with Clostridium coccoides and GNB. Microbial flora was different among IBS than HC on principal component analysis.
  
  
  CONCLUSIONS
  Fecal microbiota was different among IBS than HC, and different sub-types were associated with different microbiota. P. aeruginosa was more frequent and higher in number among IBS patients.
authors.affiliation: Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India.
authors.forename: Ratnakar
authors.initials: R
authors.lastname: Shukla
authors.affiliation: Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India. ujjalaghoshal@yahoo.co.in.
authors.forename: Ujjala
authors.initials: U
authors.lastname: Ghoshal
authors.affiliation: Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India.
authors.forename: Tapan N
authors.initials: TN
authors.lastname: Dhole
authors.affiliation: Departments of Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014, India.
authors.forename: Uday C
authors.initials: UC
authors.lastname: Ghoshal
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D004269:DNA, Bacterial / Q000032:analysis; D064806:Dysbiosis / Q000382:microbiology*; D019317:Evidence-Based Medicine; D005243:Feces / Q000382:microbiology*; D005260:Female; D006090:Gram-Negative Bacteria / Q000235:genetics / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000382:microbiology* / Q000503:physiopathology; D008297:Male; D064307:Microbiota / Q000235:genetics*; D008875:Middle Aged; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D012016:Reference Values; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial
keywords: Dysbiosis; Functional gastrointestinal disorder; Gastrointestinal microbiota; Quantitative real-time polymerase chain reaction