Scientist - News - 22-10-2009:

Inflammatory bowel disease and probiotics: reviews leave no doubt
Beintema, Nienke

October saw the publication of two major reviews on inflammatory bowel disease and probiotics. Both underline the potential benefits of probiotics in this context, but call for additional research.

While the European Food Safety Authority (EFSA) recently rejected all probiotic health claims it reviewed, evidence in support of probiotics continues to grow. The October issue of the International Journal of Medical Microbiology provided an important contribution: it published two major reviews on the potential effect of probiotics on inflammatory bowel disease (IBD).

Crosstalk
The first review was written by two researchers from the Rowett Institute of Nutrition and Health in Aberdeen, UK. Its conclusions are clear: probiotics have been shown to affect intestinal microbiota, intestinal barrier function and immune responses, and as such, they have a clear positive effect in the context of IBD. However, the researchers acknowledge that a lot of work remains to be done: "The future challenge is to gain an understanding of the mechanisms of crosstalk between microbes and host tissues," they write, "in addition to unravelling the underlying pathways driving probiotic-mediated anti-inflammatory effects." The article calls for integrated approaches using sophisticated microbiological, genomics and proteomics tools, and for tests to validate the outcomes both experimentally and clinically.

Evidence quite strong
The second article was published by two researchers from the Technische Universität München, Germany. This review, first of all, is very clear about the health effects of probiotics outside of the intestinal system: "Recent studies demonstrated the profound impact of the intestinal microbiota on the manifestation of diseases like type 1 diabetes, [...] type 2 diabetes as well as adipositas." It also refers to effects on chronic liver diseases and atopic dermatitis.
In the context of IBD, the article leaves no doubt that probiotics have a sufficiently proven effect. It notes, however, that "although clinical evidence for protective probiotic effects in colonic IBD is quite strong, randomized and placebo-controlled studies with higher numbers of study participants are necessary to clarify the efficacy of probiotic therapy in the reduction of active disease or in the context of Crohn’s Disease."

More information:
Aberdeen article in the International Journal of Medical Microbiology
München article in the International Journal of Medical Microbiology