Copyright ©2014 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Oct 28, 2014; 20(40): 14805-14820
Published online Oct 28, 2014. doi: 10.3748/wjg.v20.i40.14805
Intestinal microbiota pathogenesis and fecal microbiota transplantation for inflammatory bowel disease
Zi-Kai Wang, Yun-Sheng Yang, Ye Chen, Jing Yuan, Gang Sun, Li-Hua Peng
Zi-Kai Wang, Yun-Sheng Yang, Gang Sun, Li-Hua Peng, Department of Gastroenterology and Hepatology, Chinese PLA General Hospital, Chinese PLA Medical Academy, Beijing 100853, China
Ye Chen, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangdong Provincial Key Laboratory of Gastroenterology, Guangzhou 510515, Guangdong Province, China
Jing Yuan, Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China
Author contributions: Wang ZK drafted this manuscript; Yang YS, Chen Y, Yuan J, Sun G and Peng LH edited and revised this manuscript; all authors have approved the final version of the manuscript.
Correspondence to: Yun-Sheng Yang, MD, PhD, Department of Gastroenterology and Hepatology, Chinese PLA General Hospital, Chinese PLA Medical Academy, 28 Fuxing Road, Beijing 100853, China.
Telephone: +86-10-55499005 Fax: +86-10-55499005
Received: April 26, 2014
Revised: June 16, 2014
Accepted: July 16, 2014
Published online: October 28, 2014

The intestinal microbiota plays an important role in inflammatory bowel disease (IBD). The pathogenesis of IBD involves inappropriate ongoing activation of the mucosal immune system driven by abnormal intestinal microbiota in genetically predisposed individuals. However, there are still no definitive microbial pathogens linked to the onset of IBD. The composition and function of the intestinal microbiota and their metabolites are indeed disturbed in IBD patients. The special alterations of gut microbiota associated with IBD remain to be evaluated. The microbial interactions and host-microbe immune interactions are still not clarified. Limitations of present probiotic products in IBD are mainly due to modest clinical efficacy, few available strains and no standardized administration. Fecal microbiota transplantation (FMT) may restore intestinal microbial homeostasis, and preliminary data have shown the clinical efficacy of FMT on refractory IBD or IBD combined with Clostridium difficile infection. Additionally, synthetic microbiota transplantation with the defined composition of fecal microbiota is also a promising therapeutic approach for IBD. However, FMT-related barriers, including the mechanism of restoring gut microbiota, standardized donor screening, fecal material preparation and administration, and long-term safety should be resolved. The role of intestinal microbiota and FMT in IBD should be further investigated by metagenomic and metatranscriptomic analyses combined with germ-free/human flora-associated animals and chemostat gut models.

Keywords: Inflammatory bowel disease, Intestinal microbiota, Probiotics, Fecal microbiota transplantation, Synthetic microbiota transplantation

Core tip: Several lines of evidence strongly support the link between intestinal microbiota and inflammatory bowel disease (IBD). This review discusses the potential microbial pathogens, disturbance of intestinal microbiota, and immune interactions between host and microbes in IBD. Furthermore, alternative IBD treatment approaches aimed at restoring the disturbed intestinal microbiota have become a major interest in recent years. This article also reviews the present literature concerning the clinical use of probiotics, especially fecal microbiota transplantation and its barriers, and future directions in the management of IBD.