Grant: CAG/CCFC/CIHR Summer Studentship for Research in Gastroenterology

Crohn¿s disease (CD) is a chronic inflammatory disease of the gastrointestinal tract. Canadian incidence and prevalence estimates are amongst the highest in the world. Left untreated, CD can be associated with substantial morbidity which results in significant direct health care costs. The etiology of CD is believed to be multifactorial involving genetic and environmental components. Given the high and rising disease incidence of CD, many experts believe that some environmental factor may be playing a role in disease pathogenesis. Western diets are laden with microparticular additives, including alumina-silicates (an anti-caking agent) and titanium dioxide (a food brightener). Preliminary studies have shown that low microparticle diets decrease disease symptoms, and that microparticles can cause macrophage dysfunction, increased cell death and immune system dysregulation. Our pilot study proposes the use of a novel approach for the detection and quantification of the presence of these microparticles in tissue samples taken from patients with CD in comparison to healthy intestinal control samples. Sample biopsies will be taken during endoscopy, processed according to standard pathological sample protocol in paraffin blocks, and then subjected to beamline experimentation at the Canadian Light Source (CLS) Synchrotron. A variety of beamlines will be used to deliver a micro-focused X-ray beam to the samples. The use x-ray diffraction, fluorescence and absorption spectrometry will allow for the detection of different chemical elements in the sample volume. The quantitative abundance of microparticles will also be determined. The results of this study will serve as a ¿proof of concept¿ and may lead to further studies which characterize diet microparticle presence and quantitation in vivo. This could have important implications for understanding the cause and mechanism of CD, as well as developing novel treatments for those suffering from CD.