Published online Aug 28, 2019. doi: 10.5497/wjp.v8.i3.26
Peer-review started: January 23, 2019
First decision: January 30, 2019
Revised: July 5, 2019
Accepted: July 16, 2019
Article in press: July 16, 2019
Published online: August 28, 2019
Core tip: Ulcerative colitis and Crohn’s disease are two clinical forms of inflammatory bowel disease (IBD) causing recurring diarrhea, abdominal bleeding, pain and inflammation. Scientific evidence clearly indicated the role of heredity in IBD, but an accurate cause of IBD is still unclear. However, complex interactions between genes, environmental factors and the immune system could be one of the leading causes in IBD. Gut microbiome is a key link between these factors and progression of IBD. This article reviews all contributing factors and pathogenic association in IBD. Identifying such microbial causes of the onset of IBD can help researchers to develop effective treatment strategies.