CR05 BACTERIA NOT COMMONLY ASSOCIATED WITH HUMAN FAECES IMPLICATED IN ETIOLOGY OF POUCHITIS

Purpose  Chronic pouchitis is an important long-term complication following ileal pouch formation. Antibiotics reduce symptoms indicating bacteria play a role in pathogenesis. We analyzed and compared the bacterial content (microbiota) of stool collected from chronic pouchitis and familial adenomatous polyposis patients. Additionally, we compared the microbiota of chronic pouchitis patients on and off antibiotics. We aimed to determine which of the bacterial inhabitants of pouches had a role in the pathogenesis of pouchitis. Methods  The stool microbiota of 17 patients with chronic pouchitis and of 15 familial adenomatous polyposis patients were analyzed by nucleic acid-based methods (temporal temperature gradient gel electrophoretic profiles, fluorescence in situ hybridization with flow cytometry). Results  The composition of the stool of chronic pouchitis and familial adenomatous polyposis patients was markedly different. Electrophoretic profiles of the stool microbiota of familial adenomatous patients clustered at the 80% level of similarity, whereas those of chronic pouchitis patients were disparate. The results of fluorescence in situ hybridization analysis showed that bacteria not commonly present in human faeces, nor in the stool of familial adenomatous polyposis patients, comprised about 50% of the stool microbiota of untreated chronic pouchitis patients. Antibiotic treatment reduced the proportion of these unknown bacteria in the stool of every chronic pouchitis patient. Conclusion  Chronic pouchitis is associated with a microbiota that contains bacteria not commonly associated with human faeces. These bacteria are reduced with antibiotics and are likely to be the pathogenic agents of chronic pouchitis.