P736 Composition of faecal microbiota in former UC patients after restorative proctocolectomy with and without episodes of pouchitis
P. Bours*1, S. Fuentes2, C. Gerritsen2, 3, A. Masclee1, H. Smidt2, M. Pierik1, D. Jonkers1
1Maastricht University Medical Centre, Gastroenterology and Hepatology, Maastricht, Netherlands, 2Wageningen University, Laboratory of Microbiology, Wageningen, Netherlands, 3Winclove Probiotics B.V., Amsterdam, Netherlands
Pouchitis is a common complication after proctocolectomy with ileal pouch-anal anastomosis (IPAA) in former ulcerative colitis (UC) patients. The frequency of episodes of pouchitis varies markedly between patients. We hypothesized that IPAA patients with a documented history of pouchitis have altered faecal microbiota as compared with asymptomatic IPAA patients, and that changes in microbiota are most pronounced in those with a frequent history of pouchitis. The aim of this cross-sectional study was to evaluate faecal microbiota composition between IPAA patients with and without (recurrent) pouchitis.
UC patients with IPAA construction between 1990 and 2009 were invited to complete a questionnaire on medication usage, symptom,s and history of pouchitis, which was cross-checked by hospital records. Patients were stratified by frequency of pouchitis episodes (no [PO], 1 [P1] or >1 episode [P2]). Faecal samples were used for analysis of calprotectin and for characterisation of faecal microbiota using the Human Intestinal Tract chip (HITChip). The Shannon Diversity Index (SDI) was compared between groups (P0 vs P1 vs P2) and P0 versus a combined group of P1+P2. Group-wise comparisons were corrected for false discovery rate (FDR). Multivariate analyses using redundancy analysis (RDA) were performed to determine associations between microbiota composition and host variables.
In total, 50 IPAA patients were analysed, with a mean (SD) age of 48.2 (12.6) yr and follow-up after IPAA of 11.5 (6.5) yr, of which 26 (52%) P0, 9 (18%) P1, and 15 (30%) P2. No significant differences were observed between demographics (age, gender, BMI, and smoking) and medication use, except for more biological use in P2 (p < 0.01). In P1+P2, higher faecal calprotectin levels (p < 0.01) and a lower SDI (p = 0.05) were found versus P0. Faecal microbiota in P1+P2 showed lower levels of members of the Bacteroidetes phylum (ie, Prevotella melaninogenica), as well as butyrate-producing Clostridium cluster XIVa species, whereas increased relative abundance was observed for potential pathogenic bacteria belonging to the Proteobacteria (ie, Haemophilus, Klebsiella pneumoniae, or Serratia), as well as Actinobacteria and Bacilli phyla. Using RDA, only classification of group P0 versus P1+P2 (p = 0.01, FDR = 0.28) significantly influenced sample distribution, with alterations being most pronounced in P2 versus P0.
In patients with a known history of pouchitis, faecal microbiota diversity is reduced and associated with decreased levels of potentially beneficial bacteria. Further research on therapeutic strategies to restore these perturbations is warranted and might decrease the risk of developing pouchitis.