Probiotics are a common supplement taken by people with irritable bowel syndrome. Despite their widespread use, the latest review of the evidence does not build a strong a case for a benefit.

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder affecting around 10 percent of people. Symptoms of IBS include including abdominal pain and changes in the pattern of bowel movements. The cause of IBS is unknown, but environmental factors such as changes in routine, emotional stress, infection and diet can all trigger an attack.

Medication, diet and lifestyle are the main treatment options for IBS. There is good evidence for a therapeutic benefit of supplementing the diet with 10 grams of psyllium per day. A low FODMAP diet is also gaining attention as a treatment option.

One emerging treatment for IBS is probiotics. The research field for the use of probiotics in IBS is mixed. There is also mixed views at to which bacterial species and the form they are found in are best.

Seeking further resolution on whether probiotics should be a recommended option for IBS, the British Dietetic Association produced a systematic review on the topic. Nine systematic reviews and 35 randomised controlled trials using 29 different probiotic formulations informed the conclusion. The results showed that no strain or dose-specific probiotic was consistently effective in improving any symptoms of IBS or quality of life.

Because of the large degree of variation in the studies, there just weren’t enough clinical trials to build a case for any one strain. High-quality trials of probiotics in IBS that focus in on just a few select strains are needed.

Implications

For someone wishing to try probiotics to manage IBS, consider selecting one product at a time and then monitor the effects. Give the probiotic time to work; a minimum four weeks at the dose recommended by the manufacturer is advised.

Last Reviewed: 16/11/2019

Norman Swan Medical Communications



References

McKenzie YA et al. British Dietetic Association systematic review of systematic reviews and evidence-based practice guidelines for the use of probiotics in the management of irritable bowel syndrome in adults (2016 update). Journal of Human Nutrition 2016;29:576-592.