Background: Therapy trials with bacterial compounds in irritable bowel syndrome (IBS) have produced conflicting results and, so far, an E.-coli preparation has not been used.
Methods: Two hundred and ninety-eight patients with lower abdominal symptoms diagnosed as IBS were treated for 8 weeks by the compound Symbioflor-2 (Symbiopharm GmbH, Herborn, Germany), an Escherichia coli product (N = 148), or placebo (n = 150) in a double-blinded, randomized fashion. Patients were seen weekly by the physician, who assessed the presence of core IBS symptoms. Both an abdominal pain score (APS) as well as a general symptom score (GSS) were used as primary endpoints. Responders had to have complete absence of IBS core symptoms at > or = 1 visit during treatment.
Results: The responder rate in GSS to the drug was 27 / 148 (18.2 %) in comparison to placebo with 7 / 150 (4.67 %) (p = 0.000397). The improvement in APS was 28 / 148 (18.9 %) and 10 / 150 (6.67 %) for placebo (p = 0.001649). The response was reached from visit 3 onwards with both medication and placebo. Post-hoc analysis revealed no significant differences in efficacy of the drug between the gender and different age groups.
Conclusion: Treatment of IBS with the probiotic Symbioflor-2 is effective and superior to placebo in reducing typical symptoms of IBS patients seen by general practitioners and by gastroenterologists.