INFORMATION ABOUT OUR BREATH TESTING
Breath Testing for hydrogen and methane has been used for decades in the diagnosis of digestive disorders of carbohydrate absorption, and more recently for small intestinal bacterial overgrowth (SIBO). They are based on the principle that when bacteria (in the intestine) digest carbohydrates (sugars, starches or vegetable fibers), they produce CO2 (as all other cells do) and hydrogen (H2) as well as methane (CH4). Some bacteria also produce hydrogen sulfide (H2S) but the clinical significance of this is still under investigation, and measurement of this gas has not yet a firmly established role in diagnostics. These gases get absorbed into the bloodstream and are exhaled, paving the way for end-expiratory analysis of breath samples for the diagnosis of associated disorders. When either hydrogen or methane appear in the exhaled air, it is a sign that such carbohydrates have been exposed to bacterial metabolism.
Since absorption of glucose and fructose, as well as the disaccharides lactose and sucrose (after enzymatic splitting) occur in the small intestine, where bacteria are ordinarily not present in significant numbers, these absorptive processes do not lead to a significant rise in hydrogen or methane in breath samples of normal individuals. If, however, absorption is impaired, the unadulterated sugars reach the colon, are fermented and the hydrogen/methane production is significantly increased. The same holds true if there are abnormally high bacterial counts in the small bowel.
Some patients produce more hydrogen, some others more methane, in part because their bowel flora contains more methanogenic bacterial strains that convert hydrogen to methane. Measuring hydrogen alone (older breath-test analyzers) would therefore miss such patients, increasing the false negative test result rate.
Our Technology
We utilize state-of-the-art gas chromatography analyzers that measure both hydrogen and methane concentrations very precisely and accurately. The analyzer also measures the CO2 concentration in the breath sample and applies a correction factor to the measured hydrogen and methane values to normalize these to a standardized CO2 concentration – and therefore adjust for potential variations of gas concentrations during sampling. This is necessary because during the breath cycle CO2 concentrations (and those of the other gases) vary, due to potential mixing with air in the dead space/room air). In alveolar air the “normal” concentration of CO2 is around 5.5.% (equivalent to 40 mm Hg partial pressure) at sea level – and our machines are calibrated with this value to account and correct for improper sampling variations. Our analyzers are regularly calibrated with standardized gas mixtures to assure quality of analysis.
All our technicians are trained by a board-certified gastroenterologist in the on-site sampling technique, performance of the analysis and in the interpretation of the test results. Results are also submitted to the gastroenterologist for review to assure correct interpretation. The customer receives the results from our company and can of course share them with a provider of their choice. Because of HIPAA regulations we will not regularly share results with providers directly, except if specific arrangements are made to comply with such regulations.
For our customers who choose to do the sampling in the comfort of their home, (and mail in their sample) they will receive a complete sampling kit with detailed instructions, including a video explaining the sampling technique, and return-mail supplies. The samples are then processed in our facility using the system that assures accurate sample processing in the same analyzers used for our in-house samples.
The most common application of these breath tests is for the diagnosis of Lactose Intolerance. This is a very common condition, not only in various ethnic groups, but also in older age, and associated with other illnesses (Celiac disease, Diabetes mellitus etc.).
More recently, SIBO has received a lot of attention – and is considered relatively common in patients after antibiotic therapy, after intestinal surgery, or as a result of medical therapies for a variety of conditions (e.g., acid reflux treatment etc.). It also seems to be associated with diseases that lead to gut motility problems or alter the intestinal environment, e.g., Scleroderma, Diabetes (especially with neuropathy, gastroparesis etc.), Hypothyroidism, Inflammatory bowel disease, Diverticulosis and many others.
Other disorders that can be diagnosed by breath testing are less well known, but are nevertheless rather common contributors to common GI-symptoms:
Fructose Malabsorption
Sorbitol Sensitivity
>> Patients with these sensitivities may in fact be erroneously lumped into having a diagnosis of irritable bowel syndrome, rather than having a specific and treatable diagnosis of their specific carbohydrate-related disorder.
Hydrogen breath tests (and more recently methane) has been used for decades in the diagnosis of digestive disorders of carbohydrate absorption, and more recently for small intestinal bacterial overgrowth (SIBO). They are based on the principle that when bacteria (in the intestine) digest carbohydrates (sugars, starches or vegetable fibers), they produce CO2 (as all other cells do) and hydrogen (H2) as well as methane (CH4).
Some bacteria also produce hydrogen sulfide (H2S) but the clinical significance of this is still under investigation, and measurement of this gas has not yet gained a firmly established role in diagnostics.
These gases get absorbed into the bloodstream and are exhaled, paving the way for end-expiratory analysis of breath samples for the diagnosis of associated disorders.
Stool testing, for example a stool microbiome assay, is an important tool in gut health diagnostics, but it is NOT suitable as a first test when dealing with common GI symptoms, like bloating, intermittent loose stools/diarrhea, constipation, or cramping. Simple hydrogen/methane breath tests are much more helpful as a first-line test for such patients, since they are particularly useful to exclude or diagnose common disorders such as lactose intolerance, SIBO/IMO, Fructose malabsorption and other carbohydrate digestion/absorption disorders. As such they are also a big part in differentiating such patients from “true” IBS patients, who share many of these common symptoms. This is well documented in the peer-reviewed literature. These tests are rapid (24-hour turnaround), very accurate, and significantly more affordable, and can help directly in identifying a root cause such as SIBO/IMO, lactose intolerance, fructose malabsorption, or sucrose intolerance. These conditions, although similar in their symptoms, each require dramatically different clinical interventions for therapy —e.g. specific antibiotic therapy +/- diets/probiotics for IMO or bacterial overgrowth, Lactose Intolerance requires a lactose free diet or lactase-supplements. Breath testing therefore provides precise, actionable insights to advance patients toward optimal care.
Stool microbiome testing on the other hand does not generally diagnose specific diseases (aside from possible detection of specific pathogenic organisms in infectious diarrhea patients). It can reveal imbalances in the stool flora, even though there is no widespread agreement, yet about what a normal microbiome has to look like. It can reveal clues about inflammatory or autoimmune processes but generally does not pinpoint to a specific disorder. In addition, it cannot localize the illness or disorder (e.g. small intestine versus colon) – whereas breath testing can help pinpoint the exact source of the issue (e.g. small intestinal bacterial overgrowth, lactose intolerance etc.). Stool microbiome testing and other stool-based tests may therefore be employed later in the work-up of GI symptoms, to gain insight into what general process is contributing to the symptoms – after excluding the common disorders mentioned above, that are easily diagnosed with the simple hydrogen/methane breath tests.