Molecular analysis of the luminal- and mucosal-associated intestinal microbiota in diarrhea-predominant irritable bowel syndrome

• Published in: American journal of physiology: Gastrointestinal and liver physiology Vol. 301; no. 5; pp. G799 - G807
• Main Authors: Carroll, Ian M., Ringel-Kulka, Tamar, Keku, Temitope O., Chang, Young-Hyo, Packey, Christopher D., Sartor, R. Balfour, Ringel, Yehuda
• Format: Journal Article
• Language: English
• Published: United States American Physiological Society 01.11.2011
• Subjects: Adult; Biodiversity; Colon - microbiology; Diarrhea; Diarrhea - microbiology; DNA, Bacterial - genetics; Feces; Feces - microbiology; Female; Humans; Intestinal Mucosa - microbiology; Irritable bowel syndrome; Irritable Bowel Syndrome - microbiology; Male; Metagenome - genetics; Microbiology; Middle Aged; Neuroregulation and Motility
• ISSN: 0193-1857; 1522-1547; 1522-1547
• DOI: 10.1152/ajpgi.00154.2011

Alterations in the intestinal microbiota have been suggested as an etiological factor in the pathogenesis of irritable bowel syndrome (IBS). This study used a molecular fingerprinting technique to compare the composition and biodiversity of the microbiota within fecal and mucosal niches between patients with diarrhea-predominant IBS (D-IBS) and healthy controls. Terminal-restriction fragment (T-RF) length polymorphism (T-RFLP) fingerprinting of the bacterial 16S rRNA gene was used to perform microbial community composition analyses on fecal and mucosal samples from patients with D-IBS ( n = 16) and healthy controls ( n = 21). Molecular fingerprinting of the microbiota from fecal and colonic mucosal samples revealed differences in the contribution of T-RFs to the microbiota between D-IBS patients and healthy controls. Further analysis revealed a significantly lower (1.2-fold) biodiversity of microbes within fecal samples from D-IBS patients than healthy controls ( P = 0.008). No difference in biodiversity in mucosal samples was detected between D-IBS patients and healthy controls. Multivariate analysis of T-RFLP profiles demonstrated distinct microbial communities between luminal and mucosal niches in all samples. Our findings of compositional differences in the luminal- and mucosal-associated microbiota between D-IBS patients and healthy controls and diminished microbial biodiversity in D-IBS fecal samples further support the hypothesis that alterations in the intestinal microbiota may have an etiological role in the pathogenesis of D-IBS and suggest that luminal and mucosal niches need to be investigated.