Background – Irritable bowel syndrome (IBS) is one of the most common diagnoses in gastroenterology, but current therapies are inefficient. Recent clinical trials suggest beneficial effects of certain probiotics in IBS. Objective – The aim was to evaluate the clinical efficacy of a probiotic combination (L. rhamnosus GG, L. rhamnosus Lc705, P. freudenreichii ssp. shermanii JS and a bifidobacterium) in IBS patients.
Design – Two randomised, double-blind, placebo-controlled clinical intervention trials were conducted. In the first trial, altogether 103 IBS patients received during six months daily either probiotic supplementation or placebo. In the second trial, 86 IBS patients received during five months daily either probiotic supplementation or placebo. IBS symptoms (bowel movements, abdominal pain, distension, flatulence, rumbling) were followed by symptom diaries. Outcomes – In the first trial, the total symptom score (abdominal pain+distension+flatulence+rumbling) was 7.7 (95% CI 13.9 to 1.6) points lower in the probiotic group compared to placebo (p=0.015) at six months. This means a median reduction of 42% in the symptom score of the probiotic group compared to 6% in the placebo group. The total symptom score decreased significantly also in the second trial when the probiotic group was compared to placebo (14 points vs. 3 points; p=0.0083). When each symptom was analysed separately the probiotic combination had a beneficial effect on abdominal pain (p=0.052) and bloating (p=0.023).
Conclusions – Two long-term clinical interventions indicate that the combination of these four probiotics is a useful and safe treatment option for IBS. Studies on the mechanisms of the beneficial effects are in progress.