Variation Of Intestinal Microbiota In Irritable Bowel Syndrome (IBS)Patient With A Preliminary Study, And Probiotics For Treatment Of IBS:a Systematic Review Of Randomized Controlled Trials

Objective:To analyze variations in the intestinal microbiota composition of irritable bowel syndrome (IBS) patients subjects applying PCR-DGGE, and to evaluate the efficacy of probiotics in treating IBS.Methods:Firstly, obtained fecal and intestinal juice from patient with IBS(n=18) and from physical examination people (n=10, n=9) and store the samples in-20℃. Then extact the total genomic DNA from feces, amplifing the V3region of16S rRNA genes with PCR products were used for denaturing gradient gel electrophoresis(DGGE). Clone and sequence a representative band, comparing its sequence whit sequences in GenBank database in order to indentify the type of the bacteria. Meanwhile, search PubMed, Cochrane Library, Web Of Sicence, EMbase, MD Consult, CNKI, CMB, Wang fang Data were searched for the randomized controlled trials (RCTs) of probiotics for treatment of IBS from the data of establishment of databases to June2011. Data were extracted independently by two reviewers. After evaluating the quality of documentations and retrieving of trials was evaluated data based on the standard of Cochrane Handbook5.0.2independently, two researchers cross-check the result of their research. They conduct Meta-analysis with the software RevMan5.1and assess the quality of evidence using GRADE system.Result:The DGGE profiles of the samples show the complex diversity of microflora. IBS patients’ intestinal microflora structure has distinct characteristics that were significantly different from healthy persons. With a total of20trials involving1713patients were included. Meta-analysis results show that:Probiotics were statistically significantly better than placebo in improving global symptom (SMD=-0.18,95%CI-0.28to-0.09) and the symptom of abdominal pain/discomfort (SMD=-0.18,95%CI-0.21to-0.02) and bloating (SMD=-0.11,95%CI-0.28to-0.09). Based on GRADE system, all the evidence is at low level. However, comprehensiving pros and cons, the recommendation rate is strong.Conclusions:Intestinal microflora in IBS change significantly. The current evidence shows that probiotics have a certain role in improving some of IBS symptoms. But further studies are required to confirm its efficiency as a result of disparities among different researches in aspects such as diagnostic standard, evaluating method, dose and period of treatment.