Crohn's disease causes chronic inflammation of the intestines. Common symptoms include abdominal pain and diarrhoea. Probiotics are living microorganisms that are thought to benefit health by altering the growth and activity of bacteria in the intestines thereby reducing inflammation. Seven small studies of variable quality were reviewed. The studies tested the effect of maintenance treatment with probiotics (e.g. Lactobacilli GG, Escherichia coli strain Nissle 1917, VSL#3, Saccharomyces boulardii) among patients with Crohn's disease in remission. Remission was induced by medical or surgical treatment. The studies lasted for 6 months to a year. The studies did not demonstrate any benefit for probiotic treatment. Probiotics were generally well tolerated and few side effects were reported. Reported side effects include bloating, diarrhoea, constipation, nausea and epigastric pain. Currently, there is no evidence to support the use of probiotics for the maintenance treatment of Crohn's disease. It is possible that larger studies might show that this approach to treatment is effective.
There is no evidence to suggest that probiotics are beneficial for the maintenance of remission in CD. All of the included studies enrolled small numbers of patients and may have lacked statistical power to show differences should they exist. Larger trials are required to determine if probiotics are of benefit in Crohn's disease.
Crohn's disease (CD) is characterised by episodes of disease activity and symptom-free remission. Probiotics are microorganisms that can potentially benefit health, and have been evaluated as an alternate means of preventing relapse in patients with CD.
To assess the effectiveness of probiotics for the maintenance of remission in CD.
The following databases were searched: the Cochrane Database of Systematic Reviews (2005, Issue 3); the Cochrane Central Register of Controlled Trials (2005, Issue 3); the Cochrane IBD/FBD Group Trials Register (2005), MEDLINE (1966 - 2005); EMBASE (1980 - 2005); ISI Web of Knowledge (BIDS) 1981 - 2005; On-line clinical trials databases (2005); and review articles. Experts in the field were contacted for unpublished data.
Randomised controlled trials of probiotic therapy.
Two independent reviewers performed data extraction and assessment of methodological quality. The primary outcome was the relative risk (RR) of relapse after maintenance treatment (and 95% confidence intervals [CI]).
Seven small studies were identified and varied according to probiotics tested, methodological quality and medication regimen. No studies were pooled for statistical analysis.
There was no statistically significant benefit of E. coli Nissle for reducing the risk of relapse compared to placebo (RR 0.43, 95% CI 0.15 to 1.20), or Lactobacillus GG after surgically-induced remission (RR 1.58, 95% CI 0.30 to 8.40) or medically-induced remission (RR 0.83, 95% CI 0.25 to 2.80).
There was no statistically significant benefit of probiotics for reducing the risk of relapse compared to maintenance therapy employing aminosalicylates or azathioprine (RR 0.67, 95% CI 0.13 to 3.30), and in this study the probiotic Lactobacillus GG was associated with adverse events.
In children, there was there was no statistically significant difference between Lactobacillus GG and placebo for reducing the risk of relapse (RR 1.85, 95% CI 0.77 to 4.40).
A small study using the yeast Saccharomyces boulardii demonstrated a difference that was not statistically significant in favour of probiotic combined with a reduced level of maintenance therapy over standard maintenance treatment alone (RR 0.17, 95% CI 0.02 to 1.23).