Retrospective Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 7, 2018; 24(13): 1464-1477
Published online Apr 7, 2018. doi: 10.3748/wjg.v24.i13.1464
Fecal microbial dysbiosis in Chinese patients with inflammatory bowel disease
Hai-Qin Ma, Ting-Ting Yu, Xiao-Jing Zhao, Yi Zhang, Hong-Jie Zhang
Hai-Qin Ma, Ting-Ting Yu, Xiao-Jing Zhao, Yi Zhang, Hong-Jie Zhang, Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu Province, China
Author contributions: Ma HQ and Zhang HJ conceived the study; Ma HQ and Yu TT performed the research; Zhao XJ and Zhang Y analyzed the data; Ma HQ wrote this manuscript; Zhang HJ supervised the report.
Supported by the National Natural Science Foundation of China, No. 81470827.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of the First Affiliated Hospital of Nanjing Medical University.
Informed consent statement: All study participants provided informed written consent prior to study enrollment.
Conflict-of-interest statement: All authors declare no conflicts of interest related to this article.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Hong-Jie Zhang, MD, PhD, Professor, Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, Jiangsu Province, China.
Telephone: +86-25-83718836-6920 Fax: +86-25-83674636
Received: January 10, 2018
Peer-review started: January 10, 2018
First decision: February 5, 2018
Revised: March 5, 2018
Accepted: March 7, 2018
Article in press: March 7, 2018
Published online: April 7, 2018
Research background

Inflammatory bowel disease (IBD) is generally defined by two nonspecific inflammatory disorders, Crohn’s disease (CD) and ulcerative colitis (UC), which are characterized by chronic persistent inflammation of the intestinal mucosa lining the intestinal tract. Recently, distinctive microbial composition and its interaction with the host immunological response are believed to play critical roles in the pathogenesis of IBD. Although the intestinal microbial composition of Western IBD patients has been extensively studied, there are conflicting reports about changes of the bacterial abundance. What’s more, the intestinal microbial profiles of Chinese IBD patients are not well characterized. In the present study, we use 16S rDNA amplicon-based analysis to analyze the alterations of fecal microbiota in Chinese patients with IBD.

Research motivation

Although the microbial community is gaining increasing attention for its influence on IBD, there is a lack of data on global alteration of microbiota in Chinese patients and the relationship is poorly understood. This study would characterize the important differences of fecal microbiota between Chinese IBD patients and healthy controls based on a 16S rDNA sequencing analysis, hoping to explore which kinds of the microbiota could be involved in the pathogenesis of IBD or providing important references for diagnosis or treatment of IBD.

Research objectives

The research aimed to investigate the differences in quantity, diversity and similarity of the fecal bacterial population taken from Chinese IBD patients at different stages of disease and healthy individuals.

Research methods

Twenty-nine IBD patients (11 active CD, 4 inactive CD and 14 active UC patients) from the First Affiliated Hospital of Nanjing Medical University (Jiangsu, China) and 13 sex and age well-matched healthy individuals were enrolled in the study. 16S rDNA amplicon-based sequencing was used to analyze the fecal microbiota of each sample.

Research results

In this study, community richness (chao) and microbial structure in IBD were significantly different from those in normal controls. The relative abundance of Bacteroidetes in the active CD group was significantly lower than that in the inactive CD group, and it showed a negative correlation with Crohn’s disease activity index (CDAI). At the phyla level, the abundance of Proteobacteria was significantly higher in IBD than in controls. At the genera level, 8 genera in CD and 23 genera in UC (in particular, the Escherichia genus) showed significantly greater abundance as compared to that in normal controls.

Research conclusions

Our study presented a comprehensive analysis of fecal microbiota in the gut of Chinese patients with IBD. Significant differences in microbial composition of patients with IBD and controls were observed. Additionally, the negative correlation between Bacteroidetes and CDAI suggested that Bacteroidetes might have a negative impact on development of inflammation.

Research perspectives

Fecal microbial examination is noninvasive and easily collected compared with the mucosal biopsy, which may increase the risk of unexpected bleeding.However, the mucosa-associated microbiota is believed to directly affect epithelial and mucosal function. In the future, both the fecal and mucosa-associated microbiota should be investigated together to better understand the role of the intestinal microbiota in health and disease.