New Research on Biomarkers and MRI Imaging Suggests Directions for Future Diagnosis and Treatment of Irritable Bowel Syndrome (IBS)
January and February 2014 appear to have been good months for IBS research, which may be encouraging to those of us with IBS that scientists around the globe continue to work hard on our behalf. Multiple news reports and newly published study results from separate teams in different countries are intriguing and worthy of mention here.
In one recently published study, involving a collaboration of researchers from Macquarie University and the University of Newcastle, both in Australia, as well as from the University of Michigan at Ann Arbor and Prometheus Laboratories, a pharmaceutical and diagnostic products company in San Diego, California, both in the United States, evaluated 244 research subjects. This group included people with identified IBS with diarrhea, IBS with constipation, IBS with mixed subtype, and without any other known functional gastrointestinal disorders. The researchers selected 34 possible genetic and serological (immune) markers based on factors known to be problematic in IBS as well as whole genome analysis. They also considered 4 additional psychological markers related to depression, anxiety and somatization (psychological distress expressed as physical symptoms). They found that a combination of the 34 biological markers was effective in distinguishing those who had IBS from those who did not have it, and that the addition of the 4 psychological factors increased this ability to distinguish IBS from the healthy controls. Furthermore, the biological factors were relatively effective in distinguishing subtypes of IBS, most successfully between IBS-D and IBS-C. However, in this case, the psychological factors had almost no effect. The findings of this study open the door to the potential development of reliable diagnostic tests for IBS in the future.
A second team of researchers from the University of Nottingham, a major center for IBS research in the United Kingdom, recently published three separate studies in which they successfully used MRI imaging techniques. Previously, researchers were limited to X-rays of the colon, which did not allow as detailed observation as MRIs, and might present radiation risks, especially to children and to women of childbearing age, who are a large proportion of people with IBS. In one study, the Nottingham researchers were surprised to discover that their study subjects with faster than normal transit times, such as in IBS-D, had colons about the same size as volunteers with normal transit. However, in those with IBS, the first part of the colon, known as the ascending colon, was unable to expand as much as normally to allow the contents to move down the colon. The MRI technique now allows researchers to measure the difference, and potentially, in the future, use medications to address this specific problem. The Nottingham researchers were also able to use MRI imaging to study gastrointestinal motility in a second study, and in a third study on healthy volunteers and FODMAPS. It is already known by IBS researchers that a low-FODMAP diet is helpful to many people with IBS. Now that the Nottingham team has data on healthy volunteers, it plans to follow up with studies on people with IBS that will hopefully shed more insight into absorption or malabsorption of specific foods, colonic distension and the mechanisms of how the low-FODMAP diet works.
Finally a recent news item from the website Medical News Today reports the creation of an interdisciplinary network of 70 research groups from 19 European countries known as GENIEUR (Genes in Irritable Bowel Syndrome Europe) to study the genetic factors that may lead the development of IBS. Presently, according to the article, only a few genes that predispose an individual to IBS are known. GENIEUR, led by top IBS researchers from the University of Gothenburg and the Karolinska Institutet, both in Sweden, and the University of Heidelberg in Germany, hopes to set up a biobank that includes samples from a large number of people with IBS and healthy controls that will eventually assist them in further identifying genetic influences and biomarkers for IBS. It should be emphasized that all of the research mentioned above is still preliminary, and much more study is needed before usable and reliable diagnostic tests and targeted treatment for IBS are available and well accepted by the medical community at large. However, each of the reports cited above appears promising, with the potential to lay the groundwork for major progress in the diagnosis and treatment of irritable bowel syndrome worldwide in the future.
Two frustrating things about irritable bowel syndrome for people who have it and the health care professionals who provide care to us are that there are currently no laboratory tests that can be done in a clinical setting to diagnose IBS or determine the most effective treatment options for any given individual with IBS. Although several decades of research have established numerous known and possible abnormalities that exist in people with IBS, none of this is obvious by examining a person’s colon, blood work or other tests outside of a research context. For over 20 years, international experts in functional gastrointestinal disorders have recommended the use of the Rome criteria, which uses patterns of symptoms to diagnose IBS. They estimate that a Rome III diagnosis is 98% accurate. However, as written on this blog on October 9, 2011, a 2010 study unfortunately showed that large numbers of primary care physicians, gastroenterologists and nurse practitioners still believe the outdated notion that IBS is a diagnosis of exclusion to be given only when everything else that could cause similar symptoms is ruled out. This enduring misconception, which also exists among the general public and many people with IBS themselves, can be very damaging to individuals with IBS who may not get appropriate medical care, sufficient social support from family and friends, accommodations from schools or employers, despite legal protections in the U.S. and some other countries, or disability benefits if needed because of the belief that medical tests are “normal” and nothing serious is wrong. Even when IBS is quickly and correctly diagnosed and the health care provider is knowledgeable, because there is no way to test for each person’s specific needs, many people with IBS face months or years of trial and error with various treatment interventions that have been shown to be helpful for some subset of people with IBS, not necessarily us. Any scientific breakthroughs that allow doctors to demonstrate readily observable structural, metabolic or genetic changes, will ultimately help them to diagnose and treat those of us with IBS more precisely and further legitimate our medical condition and needs as individuals and as the IBS community.