Studies of how and which types of probiotics improve IBS symptoms have yielded contradictory results. Some studies have shown that probiotics improve IBS, while others have resulted in less promising findings. This variance reflects, in part, differences in the studies, such as trial design, the limited number of participants, and the type, dose and formulation of the probiotics used in a particular study.
The term “probiotics” refers to the beneficial bacteria that are ingested to improve intestinal health. Some probiotic supplements contain just one bacterial strain whereas others have up to 8 different strains. It is reasonable that different studies will reach different conclusions, directly dependant upon the type of strains used. Similarly, the quantity of bacteria in each probiotic supplement can vary from a low of about one million to more than 400 billon organisms per dosage – and this too will also influence results.
In order to determine whether there is a statistical benefit of probiotics in easing the symptoms of IBS, researchers will review hundreds of studies and select those that have been done following specific guidelines for creditability.
The selected studies are then evaluated using a statistical method called meta-analysis. This involves combining all the studies and measuring the outcome for a specific issue. For example, there may be 20 studies evaluating the effects of probiotics on IBS. Some studies may have positive results and others negative. Combining all the results can give an overall statistical evaluation of whether probiotics are beneficial.
Over the last 18 months there have been four major meta-analysis reports published in respected medical journals (1,2,3,4).
All four meta-analysis studies concluded that probiotics benefit individuals suffering with IBS. They all found that probiotics could ease the symptoms of:
- Abdominal pain
- Improve the passage of stools
Only a few minor adverse side effects were reported, the most common being a temporary increase in abdominal bloating and flatulence. No serious health or safety issues were identified.
The Conclusion: Probiotics are Promising
The general conclusion from these reports is that probiotics offer promise in the treatment of IBS. Further studies of longer duration and use of specific strains and dosages of probiotics are needed to determine which probiotics are statistically better in treating IBS.
Because the drug therapies currently available to IBS sufferers have shown limited success, a trial of probiotics certainly seems worthwhile.
Take Home Message
Probiotics are helpful in treating the symptoms of IBS. Look for one that has at least 5 billon bacteria in a serving size and contains multiple strains of lactobacillus and bifidobacteria…like EndoMune.
Eat healthy, exercise and stay well!
(1) A systematic review and meta-analysis: probiotics in the treatment of irritable bowel syndrome.Hoveyda N, Heneghan C, Mahtani KR, Perera R, Roberts N, Glasziou P. BMC Gastroenterol. 2009 Feb 16;9:15.
(2) Meta-analysis of probiotics for the treatment of irritable bowel syndrome. McFarland LV, Dublin S. World J Gastroenterol. 2008 May 7;14(17):2650-61.
(3) The efficacy of probiotics in the therapy of irritable bowel syndrome: a systematic review.Moayyedi P, Ford AC, Talley NJ, Cremonini F, Foxx-Orenstein A, Brandt L, Quigley E. Gut. 2008 Dec 17
(4) Effectiveness of probiotics in the treatment of irritable bowel syndrome. Wilhelm SM, Brubaker CM, Varcak EA, Kale-Pradhan PB. Pharmacotherapy. 2008 Apr;28(4):496-505.