Probiotics Improve the Irritable Bowel Syndrome (IBS)

There’s been controversy as to whether altering the intestinal bacterial content has any benefit in patients with irritable bowel syndrome (IBS).  So a meta-analysis of published studies of probiotic treatment is most welcome; it’s published in the journal Gut.  And, by the way, April is Irritable Bowel Syndrome Awareness Month.

The medical literature was combed for randomized, controlled clinical studies at least one week in duration; probiotics had to be compared with placebo or no treatment in adults diagnosed with IBS.  To measure the effectiveness (or lack of it) across different studies, the researchers determined the relative risk for symptoms not improving during each study.  In addition, an IBS symptoms score was established for each study.

There were 19 trials involving 1,650 patients in the analysis; in general, the trial methodology was good. Six of the studies were blinded, i.e. the patients were unaware of whether they were taking a probiotic or a placebo.  The relative risk of not improving with a probiotic was 0.71, a statistically significant result.  Thus there was evidence that probiotics are effective.  This was confirmed by 15 of the studies showing improvement in IBS symptom scores.  

Problems remain, however.  Which of several commonly-used bacilli are effective?  The analyses don’t reveal this.  And how great is the benefit?  Is it a relevant benefit?  Again, this in’t obvious from the study results.  Nevertheless, the findings are sufficiently encouraging to persuade IBS patients to make their own trial of different probiotic-containing foods, yogurts, drinks, and so on.  (My personal favorite is the yogurt Activia®, which contains bifidus regularis®, but only because it tastes so good!)