Jim Poggi
By Jim Poggi
The future for non-invasive breath-based tests
A decade ago, there was not much to talk about when it came to breath tests. On the lab side, alcohol breath tests were by far the most widely known and used breath test. Recently, H. pylori breath tests for diagnosis of peptic ulcer joined the small list of lab breath tests. On the non-lab diagnostic front, spirometry was widely used. Both alcohol and spirometry tests found their way into our primary care, ER, urgent care and other markets. They are well understood and accepted by both the distribution community and the clinicians we serve, but hardly represent a large product portfolio or clinical or revenue opportunity with our customers.
However, due to a variety of factors, including new non-invasive measurement technology and a better understanding of gastrointestinal bacteria (GI microbiota), the list of new and soon-to-be launched non-invasive tests using the breath as a sample are coming to market. In this article I intend to share information on some of these new and emerging breath-based tests.
Will all be applicable to our primary care customers? No. At the same time, some of the tests are still somewhat controversial, and clinical opinion is divided upon just how useful they are. So, there is some uncertainty about where these developments will lead us. One thing I am confident of: non-invasive breath testing is coming to our market. Each test will be judged on clinical utility, workflow efficiency and potential economic benefits.
There are three classes of new non-invasive breath based diagnostic methods entering the market:
- Gastrointestinal health assessment
- General health and cancer markers
- Gas exchange/pulmonary function tests
Gastrointestinal health assessment
- pylori testing led the charge and has been well accepted as an alternative to stool tests to detect active H. pylori infection in the GI tract. It’s used to help diagnose peptic ulcer as well as to determine whether H. pylori has been effectively eliminated from the GI tract following antibiotic therapy. Other hydrogen breath tests measure lactose and fructose intolerance to help understand whether intolerance for either of these is the cause of diarrhea, nausea, vomiting or other relatively common chronic GI disturbances. Effective use of these tests can lead to dietary modifications to improve GI and overall health. While these tests are typically not done in primary care settings, they are well established tests and improve patient care. They have potential to move into the primary care market since there is a substantial need for better diagnosis of general GI distress complaints, and public awareness is high with a range of prebiotic and probiotic nutritional supplements claiming relief of GI symptoms.
Another hydrogen breath test targeted to diagnose a cause of GI disease and discomfort is known as Small Intestinal Bacterial Overgrowth (SIBO). This test is also typically hospital based and intended to determine whether the relative amount of small intestine bacteria is normal or excessive. If determined to be excessive, the patient is put onto antibiotic therapy to remedy the bacterial overgrowth. The key consideration in this therapy is to avoid lowering the normal intestinal microbiota too much and create an invitation for C. difficile. For this reason, I don’t expect this technique to migrate out of the hospital and gastroenterology specialty market.
General health and cancer markers
There is emerging evidence that certain cancers can be detected by measuring volatile organic compounds (VOC) in breath. The principle is that certain VOC expression patterns in breath are normal and others may indicate cancer or other diseases. Further, there is evidence that different cancers have different VOC expression patterns. While research is early, it looks promising and I expect we will learn more in short order as clinical testing proceeds.
Ketone (acetone) measurements have been around in urine and serum for many years. They are used to help assess whether a person is in a state of ketosis, which is associated with the ability to selectively burn fat preferentially to carbohydrates. Ketosis is different from the dangerous condition of ketoacidosis, associated with excessive concentrations of glucose for long periods of time. Ketosis measurements are commonly used by bariatric physicians and even some home fitness users and others on diets to manage their diet to lose weight as part of an overall health program.
New breath-based products are coming to market to provide an accurate, easy-to-use system to assess nutritional status. I expect breath measurements of ketones to migrate into wellness centers and bariatric patient care practices. The test is fast, simple, accurate and helps the patient to understand their nutritional status to actively manage their weight loss program.
Gas exchange/pulmonary function tests
Traditionally, acute respiratory conditions have been diagnosed in emergency rooms with arterial blood gas (ABG) and electrolyte measurements to understand the patient’s respiratory status. While effective and offering a wide range of testing parameters including O2, CO2, pH and others, ABG has its challenges. It is particularly invasive, requires high skill in acquiring a good arterial blood sample and can take at least 15-30 minutes for a result. In acute respiratory distress, time is the enemy. It also carries some risk of infection due to its invasive nature.
Recent advances in technology have resulted in new breath-based measurements of most of the same parameters offered by ABG, but non-invasively and in under two minutes. This technology can potentially expand the usefulness of respiratory testing beyond the ER into pre-surgical patient assessment, and other clinical areas. It is just entering the hospital market and offers an interesting option to respiratory assessment in the hospital. Future in primary care? Maybe for smoking cessation clinics and management of chronic respiratory conditions.
The future for non-invasive breath-based tests is just beginning to become clear. What’s it going to take for new tests to emerge? A few factors come to mind. A better understanding of the GI tract and role of microbiota in health and disease. A deeper understanding of which substances can be reliably assessed in breath samples and development of clinical proof for new technologies. Trust your gut; it knows more than it’s telling. But we are learning more each day.