Alterations of Enteric Microbiota in Patients with a Normal Ileal Pouch Are Predictive of Pouchitis.
To examine whether patients with a mature normal pouch [> 1 year post ileostomy closure] have microbial stool characteristics that can predict pouch inflammation.



Patients undergoing pouch surgery were recruited prospectively. Microbiota analysis of faecal samples was by 16S rRNA gene pyrosequencing. All patients had a normal pouch at baseline [T1]. Those without pouchitis during the first year of follow-up [T2] comprised the 'Normal Pouch-sustained' group and those who had experienced an episode of pouchitis comprised the 'Pre-Pouchitis' group.



Twenty patients were recruited (age 53.6±13.1 years, pouch age [time from ileostomy closure] 8.1±5.1 years). Seven patients developed pouchitis during follow-up [within 265±93.6 days] and they were assigned to the Pre-Pouchitis group at T1: they had a decreased microbial diversity at T1 compared with the Normal Pouch-sustained patients [n = 13]. The Shannon diversity index for the Pre-Pouchitis patients was 3.4 vs 4.23 for the Normal Pouch-sustained patients [p = 0.011]. There were no substantial group differences in high taxonomic levels [order or above]. The genus Ruminococcus was significantly decreased in the Pre-Pouchitis patients' samples compared with those of the Normal Pouch-sustained patients (0.19% vs 0.78%, respectively, false discovery rate [FDR] = 0.05). The linear discriminant analysis with effect size estimation algorithm revealed that Lachnospira and Coprococcus genera were also decreased among Pre-Pouchitis patients compared with Normal Pouch-sustained patients [0.6% vs 1.95% and 2.1% vs 4%, respectively].



Patients with a normal mature pouch may be predisposed to acute pouchitis when faecal microbial diversity and certain microbial groups are decreased. These findings may aid in risk stratification of those patients.
Department of Gastroenterology and Liver Diseases, Tel Aviv Sourasky Medical Center, Tel Aviv University, Tel Aviv, Israel.
Nitsan
N
Maharshak
Department of Gastroenterology and Liver Diseases, Tel Aviv Sourasky Medical Center, Tel Aviv University, Tel Aviv, Israel.
Nathaniel Aviv
NA
Cohen
Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.
Leah
L
Reshef
Department of Surgery, Tel Aviv Sourasky Medical Center, Tel Aviv University, Tel Aviv, Israel.
Hagit
H
Tulchinsky
Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.
Uri
U
Gophna
Department of Gastroenterology and Liver Diseases, Tel Aviv Sourasky Medical Center, Tel Aviv University, Tel Aviv, Israel.
Iris
I
Dotan
D000328:Adult; D000368:Aged; D000068016:Eubacteriales / Q000302:isolation & purification; D039021:Colonic Pouches; D064806:Dysbiosis / Q000150:complications* / Q000382:microbiology; D005243:Feces / Q000382:microbiology*; D005260:Female; D000069196:Gastrointestinal Microbiome; D006801:Humans; D008297:Male; D008875:Middle Aged; D019449:Pouchitis / Q000382:microbiology*; D011237:Predictive Value of Tests; D012336:RNA, Ribosomal, 16S / Q000032:analysis*; D012307:Risk Factors; D045857:Ruminococcus / Q000302:isolation & purification
D012336:RNA, Ribosomal, 16S
Pouchitis; inflammation; inflammatory bowel disease; microbial diversity; microbiota