Published online Feb 28, 2018. doi: 10.3748/wjg.v24.i8.894
Peer-review started: December 13, 2017
First decision: December 27, 2017
Revised: January 12, 2018
Accepted: January 20, 2018
Article in press: January 20, 2018
Published online: February 28, 2018
The prevalence of irritable bowel syndrome (IBS) in Western societies is approximately 10%-20%, and the pathology of IBS is complicated. It is believed that multiple factors such as genetics, visceral hypersensitivity, gastrointestinal motility, dysregulation of the brain-gut axis, levels of neuropeptides and hormones, as well as inflammatory changes all contribute to IBS development.
Microbial metabolites regulate biochemical and physiological processes. Certain disorders that alter fecal microbial profiles may cause IBS. Thus, the key topic we wanted to address in this study is the impact of the microbiota on host–microbial interactions. Fecal metabolic compositions and variations not only reflect the status of the intestinal microbiota, but also bridge the relationship between symbiotic microbes and host health.
The study of fecal metabolomics offers a unique insight to investigate IBS. In the present study, differentially expressed metabolites and key metabolic pathways were found in fecal samples from IBS mice, when compared to the control group. The metabolomic profile in the IBS group was significantly altered following Clostridium butyricum treatment.
Fecal samples were analyzed using gas chromatography-mass spectrometry (GC-MS) method. The resulting three-dimensional data involving the peak number, sample name, and normalized peak area were submitted to SIMCA14.1 software package for principal component analysis (PCA) and orthogonal projections to latent structures-discriminate analysis (OPLS-DA). MetaboAnalyst was used to identify the most relevant pathways (http://www.metaboanalyst.ca).
In this study, we found differentially expressed metabolites between the control and IBS groups. C. butyricum administration modulated metabolic profiles and reduced visceral sensitivity and diarrhea symptoms in IBS mice. This study demonstrated the impact of metabolomic studies on the etiology of IBS. Supplementation with probiotics may provide great prospects for the treatment of IBS. In the future, we will focus fecal metabolomic studies in IBS patients to explore the prevalent pathways and mechanisms in humans.
Based on the GC-MS analysis, we found that fecal metabolites were changed during the pathological process of IBS. IBS mice demonstrated disorders in fecal microbial profiles, which led to fecal metabolic changes that may affect the development of IBS. This study also demonstrated the potential of metabolomic studies to provide new insights into the etiology of IBS. Probiotics can be used to improve the symptoms of IBS and alter fecal metabolites, and therefore may be used to treat IBS.
Intestinal microbiota metabolites are very complex. In the future, our research will focus on fecal metabolites in IBS patients to explore the pathophysiological mechanisms in humans. GC-MS combined with liquid chromatography (LC)-MS analysis should be considered for future studies.