Novel Breath Tests
Over the last 20 years, the staff of Metabolic Solutions has developed many unique stable isotope breath tests including measurement of hepatic function (phenylalanine and methionine), small intestinal bacterial overgrowth (xylose and sorbitol), gastric emptying, vitamin B12 status, and a pancreatic breath test to detect early-stage chronic pancreatitis. Our breath tests utilize stable isotope analysis of labeled carbon dioxide. Academic and pharmaceutical scientists are currently using these breath tests in research applications. A discussion of two newly developed tests follows:
Vitamin B12 Breath Test
Vitamin B12 deficiency is a common problem that affects the general US population and the elderly in particular. Current approaches to clinical diagnosis of vitamin B12 deficiency are inadequate because they lack specificity, have poorly defined reference ranges and are expensive. To address these shortcomings, we developed a low cost and accurate, simple to interpret diagnostic breath test for this important clinical condition. We call our test the B12 Breath Test (BBT).
The scientific principle behind the BBT is to follow the metabolism of propionate to carbon dioxide (CO2) which requires vitamin B12 as a co-factor. The stable isotope probe (1-13C-sodium propionate) is metabolized first to methylmalonic acid-CoA, then catalyzed by vitamin B12 to succinyl CoA, and ultimately metabolized to 13CO2 via the TCA cycle. The amount of 13CO2 appearing in the breath is indicative of the propionate metabolizing activity and the vitamin B12 status of an individual.
We have published the results of our work with individuals at risk of vitamin B12 deficiency. Please review this Vitamin B12 Breath Test paper.
Pancreatic Breath Test
Due to a lack of a useful screening test, chronic pancreatitis (CP) is a challenging disease to diagnose when patients present with chronic abdominal pain. Imaging tests also do not detect early CP changes. The most sensitive indicator of early-stage CP is the secretin stimulation test (SST), a direct pancreatic function test. However, the procedure is too complex to be used routinely and is only available in a limited number of medical centers.
We recognized the limitations of current tests to diagnose early CP and developed an alternative direct pancreatic function test named the Pancreatic Breath Test (PBT). The test is modeled after the secretin stimulation test but employs a novel isotope dilution technique. The PBT detects bicarbonate released from the pancreas by dilution of a 50 mg oral 13C-bicarbonate dose after stimulation with a 250 calorie liquid meal. The test uses four breath samples and is conducted within 1 hour, suitable for administration in a primary care office. Subjects with abnormal pancreatic function show little dilution of the breath 13CO2 levels. We reported our phase 1 results at the May 2012 Digestive Disease Week in San Diego that the PBT detects both mild and severe pancreatitis.