Food and irritable bowel syndrome

Irritable bowel syndrome (IBS) has always seemed like a bit of an odd term to me. Odd because whilst it is used to describe various symptoms related to the bowel, 'irritable' to me implies angry and annoyed. Assuming that a similar meaning is denoted for IBS, various notions perhaps acquire new meaning. If for example, we assume that the gut is the second brain, and our first brain (the one in our head!) is the part of us that becomes irritable, angry or annoyed in response to whatever, then one can see some sense in its use when applied to the gut.

I digress. There is quite a lot of speculation as to what causes IBS and what are the most effective ways of reducing or managing symptoms. Outside of psychological factors such as stress, diet and food have been consistently related to some cases of IBS and the suggestion that sensitivity or intolerance might be tied into symptoms. I wrote a post about this not so long ago following the publication of quite an important piece of research where non-celiac gluten intolerance seemed to be linked to some cases of IBS. Removing gluten, or rather reintroducing gluten after having previously been excluded from the diet, seemed to be linked to the appearance of various IBS symptoms over placebo.

A recent article adds to the dietary connection. The paper by Carroccio and colleagues* suggested that a quarter of their participant group were found to have a food hypersensitivity to cow's milk protein and/or gluten wheat protein. Furthermore levels of tryptase, an enzyme normally released as part of an allergic-immune response, and fecal eosinophil cationic protein (ECP), related to inflammation, were higher in those participants with IBS and food hypersensitivity. This indicating some possibility of identifying those cases of IBS with a potential dietary effect involved.

Whilst complicated, dare I say spectral, conditions such as IBS are never going to be caused by one factor and one factor alone, there is some reliable evidence emerging implicating a dietary effect as being involved. Much like lifestyle and stress-reduction treatments and pharmacotherapy, such a dietary effect if linked, provides another possible intervention route to potentially alleviating symptoms, at least for a proportion of those affected.

* Carroccio A. et al. Fecal assays detect hypersensitivity to cows milk protein and gluten in adults with irritable bowel syndrome. Clinical Gastroenterology & Hepatology. August 2011.

Milk, gut bacteria and coeliac disease

Coeliac disease (CD), that exquisite sensitivity to dietary gluten, has long been the focus of quite a bit of research. That's not to say that in all those years we don't know a little bit about CD; some of its genetics, its diagnostic markers, its treatment, but there are still lots of things we don't know about CD as well as the various non-coeliac forms of gluten sensitivity which seem to be emerging.

When it comes to early markers or risk factors for CD, there are quite a few already in the research literature. I covered some of them on one of the sister blogs (here and here). Indeed the last link including this paper on your choice of entry into the world and subsequent gut bacteria, provides a good example of what might affect your start-up gut bacteria and potentially your subsequent risk of things like CD on the back of my previous post.

Enter a new potential player into the world of CD risk; surprisingly enough from your earliest form of nourishment post-partum, milk. The research by Sanchez and colleagues* postulated a connection between the genetic risk of CD and the type of bacteria from the Bacteroides species identified in fecal samples from infants with a parent with CD. An overview of the results can be found here.

The results from this study point towards two important points:

• Genetic risk of CD as measured by the HLA-DQ genotype might influence the composition of the gut bacteria.
• The type of early feeding practices (breast vs. bottle) might also influence gut bacterial composition at different times of infancy.

Whilst there are some interesting links made in this and other studies in this area, as always we need to be cautious in jumping to conclusions. Several authors have speculated that the type of early feeding pattern might alter the risk of developing CD. The evidence is however far from conclusive; indeed whilst there may be some effect in delaying the onset of CD, delay does not mean the condition will not develop. Indeed we will have to wait for studies like this one to formally reports before we can draw any firmer conclusions.

Still what studies like this offer is an insight into the complicated world of genetics and environment in conditions like CD and how our gut bacteria might well be king-maker (or at least a prince/princess) when it comes to conferring risk and protection against lots of conditions.

* Sanchez E. et al. Influence of environment and genetic factors linked to celiac disease risk on infant gut colonization by Bacteroides species. Applied & Environmental Microbiology. August 2011.