I Spy IBS in Your Urine
Scientists have discovered chemical signatures, or biomarkers, in urine that are associated with irritable bowel syndrome (IBS). This signifies not only great potential for the development of accurate and less invasive diagnostic tools, but may also provide new mechanistic insights into the pathology of IBS.1
Plagued with symptoms of abdominal pain, bloating, constipation, and/or diarrhea, IBS is one of the most diagnosed, yet poorly understood, gastrointestinal conditions. It is a chronic disorder that can begin at any point in life. Due to the lack of an accurate lab test for the disorder itself, patients may undergo a series of symptom questionnaires and tests to rule out other diseases in the gut. These exclusionary tests might also include analysis of blood and stool samples, allergy tests, questions on bowel movements, and colonoscopies, to name a few. It may take weeks or months to see a specialist and there may be feelings of embarrassment, anxiety, and discomfort when going through some of the tests mentioned above. To further complicate IBS diagnosis, the use of questionnaires is subjective and is not always definitive since IBS can vary in symptoms between patients and over time for the same individual.
Scientists from McMaster University, in collaboration with Dr. Premysl Bercik, from the Farncombe Family Digestive Health Research Institute and Associate Professor in the Department of Medicine, Division of Gastroenterology of McMaster University, have identified a panel of biomarkers in urine that are characteristic for individuals who have IBS. We were fortunate to speak with the lead author of the study, Philip Britz-McKibbin, a Professor in the university’s Department of Chemistry & Chemical Biology. He shared with us his insights on the findings of their research exploration.
“The main goals of the study were to better understand the underlying mechanisms of the disorder, as well as identify potential biomarkers to complement standard tools, improving timely diagnosis and allowing for better treatment monitoring of patients,” Britz-McKibbin said.
Scientists gathered a group of patients with IBS (n = 42) and a control group of healthy participants (n = 20). After collecting repeat urine samples from two different occasions, they found that there were ten urinary metabolites elevated in IBS patients as compared to the control group, including several unknown compounds that were subsequently identified. These signatures were likely associated with altered gut function and low-grade colon inflammation that are indicative of IBS and accelerated collagen degradation. When asked why they chose urine as the basis for profiling, Britz-McKibbin explained that, “not only does urine provide an encompassing snapshot of the gut microbiota and dietary patterns, but it is also the most convenient and non-invasive biospecimen with better patient compliance.”
“Urine-based tests are easier to acquire and far more accessible for patients as compared to blood or stool samples. They provide insights on IBS progression that can be readily monitored,” Britz-McKibbin continued.
Some of the major limitations of the study are that participants were all adult IBS patients with other illnesses, such as depression, and had a higher intake of prescribed medications compared to the control group. Britz-McKibbin would like to see future studies incorporate recently diagnosed patients with fewer confounding factors to potentially establish causal links to the disease, including longitudinal studies.
Urine-based profiling also creates the possibility of developing screening tools for early detection of IBS that are urgently needed for validation of dietary interventions to effectively treat IBS for individual patients. “With these findings, we hope to reduce the need for colonoscopies and other invasive and expensive procedures, while providing better diagnostic and therapeutic monitoring tools for gastroenterologists,” Britz-McKibbin concluded.
Professor Britz-McKibbin disclosed that he is involved in another study which is set to be published in fall 2019. He, along with a team of scientists, are building on their findings on urine testing to detect new biomarkers that can differentiate Crohn’s disease and ulcerative colitis in children. Stay tuned!