Published online Oct 28, 2016. doi: 10.3748/wjg.v22.i40.8929
Peer-review started: June 24, 2016
First decision: August 8, 2016
Revised: August 15, 2016
Accepted: August 30, 2016
Article in press: August 30, 2016
Published online: October 28, 2016
Processing time: 124 Days and 10 Hours
To investigate the changes in microbiota in feces of patients with ulcerative colitis (UC) and pouchitis using genomic technology.
Fecal samples were obtained from UC patients with or without an ileal pouch-anal anastomosis (IPAA) procedure, as well as healthy controls. The touchdown polymerase chain reaction technique was used to amplify the whole V3 region of the 16S rRNA gene, which was transcribed from DNA extracted from fecal samples. Denaturing gradient gel electrophoresis was used to separate the amplicons. The band profiles and similarity indices were analyzed digitally. The predominant microbiota in different groups was confirmed by sequencing the 16S rRNA gene.
Microbial biodiversity in the healthy controls was significantly higher compared with the UC groups (P < 0.001) and IPAA groups (P < 0.001). Compared with healthy controls, the UC patients in remission and those in the mildly active stage, the predominant species in patients with moderately and severely active UC changed obviously. In addition, the proportion of the dominant microbiota, which was negatively correlated with the disease activity of UC (r = -6.591, P < 0.01), was decreased in pouchitis patients. The numbers of two types of bacteria, Faecalibacterium prausnitzii and Eubacterium rectale, were reduced in UC. Patients with pouchitis had an altered microbiota composition compared with UC patients. The microbiota from pouchitis patients was less diverse than that from severely active UC patients. Sequencing results showed that similar microbiota, such as Clostridium perfringens, were shared in both UC and pouchitis.
Less diverse fecal microbiota was present in patients with UC and pouchitis. Increased C. perfringens in feces suggest its role in the exacerbation of UC and pouchitis.
Core tip: Dysbiosis in pouchitis might be similar to that observed in ulcerative colitis (UC). This study aimed to determine the altered microflora in patients with UC and pouchitis, and to investigate the relationship between them. We demonstrated the reduced biodiversity of the fecal microbiota in UC and pouchitis patients. The altered composition of the intestinal microbiota in UC and pouchitis included decreased numbers of two bacteria commonly observed in UC, and higher levels of Clostridium perfringens in both UC and pouchitis. The increase of this bacterium in feces suggested that it plays a role in exacerbating UC and pouchitis.