Published online Nov 14, 2014. doi: 10.3748/wjg.v20.i42.15657
Revised: May 11, 2014
Accepted: June 26, 2014
Published online: November 14, 2014
Ulcerative colitis (UC) is a leading form of inflammatory bowel disease that involves chronic relapsing or progressive inflammation. As a significant proportion of UC patients treated with conventional therapies do not achieve remission, there is a pressing need for the development of more effective therapies. The human gut contains a large, diverse, and dynamic population of microorganisms, collectively referred to as the enteric microbiota. There is a symbiotic relationship between the human host and the enteric microbiota, which provides nutrition, protection against pathogenic organisms, and promotes immune homeostasis. An imbalance of the normal enteric microbiota composition (termed dysbiosis) underlies the pathogenesis of UC. A reduction of enteric microbiota diversity has been observed in UC patients, mainly affecting the butyrate-producing bacteria, such as Faecalibacterium prausnitzii, which can repress pro-inflammatory cytokines. Many studies have shown that enteric microbiota plays an important role in anti-inflammatory and immunoregulatory activities, which can benefit UC patients. Therefore, manipulation of the dysbiosis is an attractive approach for UC therapy. Various therapies targeting a restoration of the enteric microbiota have shown efficacy in treating patients with active and chronic forms of UC. Such therapies include fecal microbiota transplantation, probiotics, prebiotics, antibiotics, helminth therapy, and dietary polyphenols, all of which can alter the abundance and composition of the enteric microbiota. Although there have been many large, randomized controlled clinical trials assessing these treatments, the effectiveness and safety of these bacteria-driven therapies need further evaluation. This review focuses on the important role that the enteric microbiota plays in maintaining intestinal homeostasis and discusses new therapeutic strategies targeting the enteric microbiota for UC.
Core tip: The human gut is comprised of a large, diverse, and dynamic microbiota. The enteric microbiota plays an important role in regulating anti-inflammatory and immunoregulatory activities. An imbalance of the normal enteric microbiota composition, termed dysbiosis, underlies the pathogenesis of ulcerative colitis (UC). Therefore, manipulation of the dysbiosis is an attractive strategy for UC therapy. This review discusses new therapies associated with the regulation of enteric microbiota for UC patients.