Do any treatments work for irritable bowel syndrome?

Review article: probiotics for the treatment of irritable bowel syndrome--focus on lactic acid bacteria

BACKGROUND

Irritable bowel syndrome (IBS) is a poorly understood, yet highly prevalent functional gastrointestinal disorder (FGID). The withdrawal, due to adverse events, of a number of pharmacological agents that were approved for the treatment of IBS has left a therapeutic vacuum for patients suffering from the disorder.

AIM

To review, summarise and critically evaluate current knowledge of lactic acid bacteria (LAB) used to treat IBS.

METHODS

We assessed a comprehensive range of relevant literature from Pubmed, Medline and online sources based on our definition of LAB which included both typical and atypical species, covering Lactobacilli, Bifidobacteria, Enterococci, Streptococci and Bacilli.

RESULTS

Of the 42 trials evaluated examining the efficacy of LAB in IBS, 34 reported beneficial effects in at least one of the endpoints or symptoms examined, albeit with tremendous variation in both the magnitude of effect and the choice of outcome under consideration. However, numerous concerns have been expressed over deficits of trial design and execution relating to strain selection, optimum dosage, mode of action, safety and long-term tolerability in a disorder that can persist throughout the lifetime of affected individuals.

CONCLUSIONS

Progress in the field will require an improved understanding of how the microbiota impacts on health and disease, adequately powered long-term multicentre trials and the embracing of bench to bedside approaches. Recent incremental advances suggest these areas are being addressed and that the future holds much promise for the use of lactic acid bacteria in the treatment of irritable bowel syndrome.

Irritable bowel syndrome: towards biomarker identification

Irritable bowel syndrome (IBS), the most common functional gastrointestinal disorder referred to gastroenterologists, affects 7-10% of the general population worldwide. The lack of suitable disease-defining biological markers coupled with a poorly understood underlying pathophysiology complicates patient diagnosis and seriously hampers drug discovery efforts. Over the past few years, a number of potential biomarkers have emerged, and in this review we critically evaluate such candidates. In particular, we highlight the increasing number of studies supporting a low-grade immune activation in IBS and consider how the latest preclinical developments can contribute to the development of more robust and reliable biological markers of this disorder. The successful identification of biomarkers is critical to progressing our understanding of IBS and addressing the unmet therapeutic needs of this debilitating condition.