Breath Analysis Shows Promise in Distinguishing IBD Types

By Marilynn Larkin

May 10, 2019

NEW YORK (Reuters Health) - A breath analyzer can identify inflammatory bowel disease (IBD) in affected individuals and distinguish ulcerative colitis (UC) from Crohn's disease (CD), a pilot study reveals.

"There is a real drive in both research and industry to make breath analysis a reality," Dr. James Covington of University Hospitals Coventry in Warwickshire, UK, told Reuters Health by email. "IBD is an area that could really benefit from the technology and hopefully not only diagnose people quicker and without having such invasive processes, but eventually to be (used) in the home, where such technology could...monitor health, inform of potential clinical episodes and ultimately improve quality of life."

"The technology used in our study is a commercial system, which is still too expensive for primary care," he noted. "But it could be used in hospitals across the world and would be available to all."

Dr. Covington and colleagues recruited 14 individuals with CD, 16 with UC and nine controls to investigate whether volatile organic compounds exhaled in breath could be used as a noninvasive diagnostic tool, and whether fecal calprotectin (FCP), a biomarker in stool, would add diagnostic value.

As reported online April 12 in Biosensors, breath samples were analyzed using an in-house-built electronic nose (Wolf eNose) and a commercial gas chromatograph-ion mobility spectrometer (G.A.S. BreathSpec GC-IMS).

Both technologies could consistently separate IBD and controls. Areas under the curve, sensitivity and specificity were 0.81, 0.67, 0.89, respectively, for the eNose - and 0.93, 0.87, 0.89 for the GC-IMS.

Further, both the eNose (0.88, 0.71, 0.88) and the GC-IMS (0.71, 0.86, 0.62) could separate CD from UC.

Adding FCP to the eNose results did not improve the distinction between CD versus UC (0.74, 1.00, 0.56). However, it did improve separation of CD versus controls and UC versus controls: without FCP, 0.77, 0.55, 1.00 and 0.72, 0.89, 0.67, respectively; with FCP, 0.81, 0.73, 0.78 and 0.90, 1.00, 0.78.

Dr. Covington concluded, "Our next projects will look into expanding the scale of this study, but also look more closely at how to use it to improve the quality of life of IBD sufferers - eventually targeting personalized home use."

Dr. Robert Hirten an assistant professor of medicine at the Icahn School of Medicine at Mount Sinai in New York City and a gastroenterologist at its Inflammatory Bowel Disease Center, said by email, "While their initial results are very interesting, this requires further evaluation in a larger group of patients to confirm the results."

"One concern I have is that the patients with IBD in this study had some degree of gastrointestinal symptoms. This group was compared to healthy control subjects who had no symptoms at all," he told Reuters Health. "This raises the possibility that the test isn't showing a difference between patients with inflammatory bowel disease and no inflammatory bowel disease, but rather between those with symptoms and those without symptoms."

"Some gastrointestinal symptoms can be due to differences in the bacterial makeup of the intestines, such as with small intestine bacterial overgrowth, and I would want to be sure that this test isn't reflecting another variable," he concluded.


Biosensors 2019.