title: The effects of probiotics on barrier function and mucosal pouch microbiota during maintenance treatment for severe pouchitis in patients with ulcerative colitis.
abstract: BACKGROUND
  A total of 10-15% of patients with an ileoanal pouch develop severe pouchitis necessitating long-term use of antibiotics or pouch excision. Probiotics reduce the risk of recurrence of pouchitis, but mechanisms behind these effects are not fully understood.
  
  
  OBJECTIVE
  To examine mucosal barrier function in pouchitis, before and after probiotic supplementation and to assess composition of mucosal pouch microbiota.
  
  
  METHODS
  Sixteen patients with severe pouchitis underwent endoscopy with biopsies of the pouch on three occasions: during active pouchitis; clinical remission by 4 weeks of antibiotics; after 8 weeks of subsequent probiotic supplementation (Ecologic 825, Winclove, Amsterdam, the Netherlands). Thirteen individuals with a healthy ileoanal pouch were sampled once as controls. Ussing chambers were used to assess transmucosal passage of Escherichia coli K12, permeability to horseradish peroxidase (HRP) and ⁵¹Cr-EDTA. Composition and diversity of the microbiota was analysed using Human Intestinal Tract Chip.
  
  
  RESULTS
  Pouchitis Disease Activity Index (PDAI) was significantly improved after antibiotic and probiotic supplementation. Escherichia coli K12 passage during active pouchitis [3.7 (3.4-8.5); median (IQR)] was significantly higher than in controls [1.7 (1.0-2.4); P < 0.01], did not change after antibiotic treatment [5.0 (3.3-7.1); P = ns], but was significantly reduced after subsequent probiotic supplementation [2.2 (1.7-3.3); P < 0.05]. No significant effects of antibiotics or probiotics were observed on composition of mucosal pouch microbiota; however, E. coli passage correlated with bacterial diversity (r = -0.40; P = 0.018). Microbial groups belonging to Bacteroidetes and Clostridium clusters IX, XI and XIVa were associated with healthy pouches.
  
  
  CONCLUSIONS
  Probiotics restored the mucosal barrier to E. coli and HRP in patients with pouchitis, a feasible factor in prevention of recurrence during maintenance treatment. Restored barrier function did not translate into significant changes in mucosal microbiota composition, but bacterial diversity correlated with barrier function.
authors: Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors: M
authors: M
authors: Persborn
authors: J
authors: J
authors: Gerritsen
authors: C
authors: C
authors: Wallon
authors: A
authors: A
authors: Carlsson
authors: L M A
authors: LM
authors: Akkermans
authors: J D
authors: JD
authors: Söderholm
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001706:Biopsy; D003093:Colitis, Ulcerative / Q000601:surgery*; D039021:Colonic Pouches / Q000382:microbiology* / Q000473:pathology; D004926:Escherichia coli; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000382:microbiology; D008297:Male; D064307:Microbiota; D008875:Middle Aged; D010539:Permeability; D019449:Pouchitis / Q000188:drug therapy* / Q000473:pathology; D019936:Probiotics / Q000627:therapeutic use*; D012008:Recurrence
chemical_list: D000900:Anti-Bacterial Agents