Long-term treatment with probiotics in primary care patients with irritable bowel syndrome – a randomised, double-blind, placebo controlled trial

Abstract

Objective. Meta-analyses have indicated effect of probiotics on irritable bowel syndrome (IBS). However, few long-term trials have been conducted and uncertainty remains as to effectiveness and long-term effect in a primary care setting. We aimed to investigate the effect of probiotics compared with placebo in the management of IBS in primary care during a 6-month treatment period and with a 6-month follow-up. Material and methods. We randomized IBS patients fulfilling Rome III criteria to receive two capsules twice daily either containing placebo or a probiotic mixture of Lactobacillus paracasei ssp paracasei F19, Lactobacillus acidophilus La5 and Bifidobacterium Bb12 in an amount of 1.3 × 10¹⁰ CFU per capsule. Primary endpoint was proportion of responders defined as patients reporting adequate relief (AR) at least 50% of the time in the 6-month treatment period. Secondary outcomes were proportions of patients reporting AR at different time points, and change in gastrointestinal symptoms and health-related quality of life (HrQOL) from baseline to 6 and 12 months. Results. A total of 131 patients were included in this study. The proportion of responders in the treatment period was 52% (35/67) in the probiotic group versus 41% (26/64) in the placebo group, p = 0.18. Overall we found no difference between the groups in change in gastrointestinal symptoms after treatment. Patients improved in HrQOL, but with no statistically significant difference between the groups. Conclusion. During a 6-month treatment period, we were not able to detect a positive effect of probiotic when compared with placebo.

Key Words::

• irritable bowel syndrome
• primary health care
• probiotics
• randomized controlled trial

Acknowledgement

The authors wish to thank all patients who participated in the study. Further, we wish to thank Professor Jakob Kragstrup, DMedSci, PhD, for contributions during the planning of the study and the ARLA Food employees Ulla Svensson, PhD and Eva Ohman, who handled the supply of capsules and the fecal analyses. We also thank Lise Stark for the English proofreading. The study was funded by The Danish Dairy Research Foundation, The Mads Clausen Foundation, The Foundation of the Danish Medical Association and Trygfonden to LMB; from the Council for Quality Assurance in Primary care in the Region of Southern Denmark to DEJ, and from The Research Fund of Odense University Hospital to ODM. Arla Foods supplied the capsules for the study and analysed the fecal samples. The entire funding source had no involvement in the study.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.