Breath Hydrogen Testing FAQ’s
Overview:
Chronic bloating, flatulence, loose stools, diarrhea, abdominal cramping, and
constipation represent some of the most common digestive complaints encountered in
medicine. Yet too often, treatment based on guesswork is implemented before
identifying the underlying cause of symptoms. This often results in poor outcomes, a
prolonged period of illness, decreased quality of life, increased healthcare costs, and
both patient and physician dissatisfaction.
Breath Hydrogen Testing (BHT) is an accepted technology used in the diagnosis of 3
common causes of these GI symptoms - small intestinal bacterial overgrowth, fructose
malabsorption, and lactose malabsorption. BHT is a standard of care, is quick and easy
to use, is convenient and non-invasive, and can dramatically improve outcomes in a
short period of time. This primer covers pertinent information related to the clinical
applications of breath hydrogen testing.
FAQ’s
Q.
A.
What is the breath hydrogen test?
The breath hydrogen test measures the amount uses the measurement of hydrogen in
the breath to diagnose several conditions that cause gastrointestinal symptoms. Only
anaerobic bacteria in the colon are capable of producing hydrogen. The bacteria
produce hydrogen mainly when they are exposed to undigested sugars and
carbohydrates.
Although limited hydrogen is produced from the small amounts of unabsorbed food
that normally reach the colon, large amounts of hydrogen may be produced when there
is a problem with the digestion or absorption of food in the small intestine that allows
more unabsorbed food to reach the colon.
Large amounts of hydrogen also may be produced when the colonic bacteria move back
into the small intestine, a condition called small intestinal bacterial overgrowth (SIBO).
In this latter instance, the bacteria are exposed to foodstuffs that have not been fully
digested or absorbed. Some of the hydrogen produced by the bacteria is absorbed into
the blood flowing through the wall of the small intestine and colon. The hydrogen-
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containing blood travels to the lungs where the hydrogen is released and exhaled in the
breath where it can be measured.
Q.
A.
When is breath hydrogen testing used?
Breath hydrogen testing is used in the diagnosis of two conditions:
1. Small intestinal bacterial overgrowth (SIBO)
2. Carbohydrate malabsorption (i.e. lactose, fructose, sorbitol, sucrose)
The first condition for which breath testing is used is for diagnosing bacterial
overgrowth of the small bowel. Bacterial overgrowth of the small bowel is a condition
in which larger-than-normal numbers of colonic bacteria are present in the small
intestine. The treatment for this condition is a course of antibiotics (Metronidazole,
Neomycin, Xifaxin, Rifaximin, Amoxicillin, Augmentin, Ciprofloxacin etc.), however, any
one antibiotic may be effective at eliminating the overgrowing bacteria only 50-60% of
the time. Therefore, if symptoms do not disappear in an individual following treatment
with antibiotics, it may be useful to repeat the breath test to determine if the antibiotics
have eliminated the bacteria. If not, a different antibiotic or non-antibiotic treatment
can be tried.
The second is a condition in which dietary sugars are not digested normally. The most
common sugar that is poorly digested is lactose, the sugar in milk. Individuals who are
unable to properly digest lactose are referred to as lactose intolerant. Testing also may
be used to diagnose problems with the digestion of other sugars such as fructose,
sucrose, and sorbitol. Symptoms such as bloating, distention, gas, abdominal pain,
urgency, frequent stools, loose stools, and diarrhea are often caused by the inability to
properly digest commonly eaten sugars. Breath hydrogen testing can help identify the
cause of these symptoms.
Q.
A.
How does breath hydrogen testing work?
The bacteria in the colon, including the anaerobic bacteria, are able to digest and use
sugars and carbohydrates as food. When the anaerobic bacteria digest sugars and
carbohydrates, they convert some of them into gases, most commonly hydrogen. They
also may produce and release into the colon other substances, for example, substances
that cause the colon to secrete water and cause diarrhea. As previously discussed, some
of the hydrogen gas is absorbed by the colon into the blood and is eliminated in the
breath where it can be measured. As long as little sugar or carbohydrate reaches the
colon, the small amounts of gas and other substances that are produced do not cause a
problem. When larger amounts of sugar or carbohydrate reach the colon because they
are not digested and absorbed in the small intestine, larger amounts of gas and
substances are formed in the colon.
For example, if an individual digests and absorbs the sugar in milk (lactose) normally,
then none of the lactose that is given for the test reaches the colon, and no increase in
the concentration of hydrogen in the breath is seen during the breath test. On the other
hand, if the individual does not digest and absorb the lactose completely, that is, he or
she is lactose intolerant, the lactose travels through the small intestine and enters the
colon where the bacteria digest it and produce hydrogen. An increase in hydrogen in
the breath then is seen. Other sugars for which poor digestion can be diagnosed by
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breath testing include sucrose and fructose (found in corn syrup), and sorbitol (a sugar
that is used as a low-calorie sweetener).
There are ways other than abnormal digestion of dietary sugars by which the bacteria
can cause problems. Unlike in the colon, the number of hydrogen-producing, anaerobic
bacteria in the small intestine is small. If, however, large numbers of hydrogenproducing bacteria migrate into the small intestine from the colon (a condition called
small intestinal bacterial overgrowth), the bacteria may digest the sugars and
carbohydrates before the small bowel has had a chance to digest and absorb them and
produce large amounts of hydrogen.
Finally, if individuals have abnormally rapid passage of food through the small intestine,
there may not be enough time for the small intestine to digest and absorb sugars and
carbohydrates. This results in the entry of larger amounts of sugar and carbohydrate
into the colon where the bacteria can digest and convert them to gas.
To diagnose rapid transit through the small intestine, a sugar that is not digested and
absorbed by man, such as lactulose, usually is used. In the case of rapid passage through
the small intestine, the sugar passes quickly through the small intestine and into the
colon so that hydrogen is found in the breath very soon after ingestion of the sugar. In
the case of bacterial overgrowth, glucose has been found to be more sensitive than
lactulose.
Q.
A.
How is hydrogen breath testing performed?
Q.
A.
What should the patient do prior to testing?
Q.
A.
How are the results of hydrogen breath testing interpreted?
HBT is performed with the use of a device that measures hydrogen in the breath, such
as the HydroStat Hydrogen Breath Tester. After following the pre-test protocol, a fasted
patient will breathe into the HydroStat device for a baseline measurement. Subsequent
measurements are taken after challenge with lactose, fructose, glucose, or other sugars
and recorded in the patient’s chart.
Patient pre-test preparations are important to ensure accurate results. Each patient
should follow the recommendations listed below.
The interpretation of the results of hydrogen breath testing depends on the sugar that
is used for testing and the pattern of hydrogen production after the sugar is ingested.
After ingestion of test doses of the dietary sugars lactose, fructose, sucrose or sorbitol,
any production of hydrogen means that there has been a problem with digestion or
absorption of the test sugar and that some of the sugar has reached the colon. When
rapid intestinal transit is present, the test dose of non-digestible lactulose reaches the
colon more quickly than normal, and, therefore, hydrogen is produced by the colonic
bacteria soon after the sugar is ingested.
Q.
A.
What are the limitations of hydrogen breath testing?
There are several limitations to hydrogen breath testing. Some individuals do not have
bacteria that produce hydrogen, and in these individuals hydrogen breath testing will
not be clinically relevant. Most of these individuals have bacteria that produce methane
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(an estimated 25-30% of cases). There also are individuals who produce both hydrogen
and methane. Methane can be measured in the breath just like hydrogen, and the
production of methane can be used for diagnosis in the same way as hydrogen. There is
much less experience with methane, however, and the production of methane is more
complex than the production of hydrogen. Therefore, it is not clear if the pattern of
methane production after ingestion of sugars can be interpreted in the same way as
hydrogen production, particularly for the diagnosis of bacterial overgrowth.
A pattern of hydrogen production that is typical for bacterial overgrowth does not
necessarily mean that an individual's symptoms are caused by the overgrowth. For
example, there may be anatomic abnormalities of the small intestine such as narrowing
or functional abnormalities in the way the muscle of the small intestine works. These
abnormalities can cause symptoms of bloating, distention, pain, and diarrhea
themselves, but they also can lead to bacterial overgrowth with its similar symptoms.
Therefore, it may be an underlying abnormality that is responsible for the symptoms
and not the bacterial overgrowth. The only way to differentiate between the two causes
of symptoms-an underlying problem or bacterial overgrowth--is to treat and eradicate
the bacteria. If the symptoms disappear, then it is more likely that it is the overgrowth
rather than the underlying abnormality that is responsible for the symptoms.
Any condition that results in the delivery of undigested or unabsorbed food to the colon
may result in abnormal breath tests when dietary sugars are used for testing. Both
pancreatic insufficiency and celiac disease can cause abnormal breath tests, in the
former instance because pancreatic enzymes that are necessary for the digestion of
carbohydrates are missing, and in the latter instance because the lining of the small
intestine is destroyed, and digested food cannot be absorbed. It may be necessary to
exclude these causes of abnormal breath tests by additional tests-pancreatic function
tests and small intestinal biopsy.
Q.
A.
Are there other ways in which hydrogen breath testing can be used?
Q.
A.
What are the side effects of hydrogen breath testing?
Q.
A.
What are the alternatives to hydrogen breath testing?
Antibiotics are used for treating bacterial overgrowth of the small bowel; however, any
one antibiotic may be effective at eliminating the overgrowing bacteria only 50-60% of
the time. Therefore, if symptoms do not disappear in an individual following treatment
with antibiotics, it may be useful to repeat the breath test to determine if the antibiotics
have eliminated the bacteria. If not, a different antibiotic or non-antibiotic treatment
can be tried.
The side effects of hydrogen breath testing are exactly what one would expect to see in
individuals who poorly digest and absorb sugars and carbohydrates, i.e., bloating,
distention, pain, and diarrhea. When lactulose is used these symptoms are unlikely to
occur or are mild because the dose of lactulose used for testing is small.
For diagnosing lactose intolerance, an alternative procedure to breath testing requires
blood samples to be taken after the ingestion of lactose. If the digestion and absorption
of lactose is normal, the levels of glucose in the blood should rise. The elevation of
blood glucose occurs because the lactose is broken down into its two component
sugars, galactose and glucose, as it is absorbed into the blood. A second alternative is to
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give a dose of lactose (or other dietary sugar) and observe an individual for symptoms.
If the individual is intolerant, bloating, distention, pain, flatulence, and diarrhea are
likely to occur. A third alternative is a trial of a diet in which the potentially-offending
sugar is strictly eliminated. All of these alternatives, however, have limitations and
problems.
Bacterial overgrowth can be diagnosed by culturing (growing) the bacteria from a
sample of fluid from the small intestine and counting the numbers of colonic bacteria
that are present. This procedure requires a tube to be passed through the nose, throat,
esophagus and stomach under x-ray guidance so that fluid can be obtained from the
small intestine. It is an uncomfortable and expensive procedure, and most laboratories
are not able to accurately culture the samples.
An alternative method for diagnosing rapid transit through the small intestine involves
eating food that is labeled with a radioactive marker and determining the time it takes
for the marker to reach the colon. Progress of the marker through the bowel is assessed with
a scanner that acts like a Geiger counter.
Q.
A.
Do I need CLIA certification to run the testing in my office?
Q.
A.
Who can administer the test?
Q.
A.
Is breath hydrogen testing covered by insurance?
Breath hydrogen testing is completely non-invasive involving breath only. As such it is
CLIA exempt. There are no special certifications governing the administration of breath
hydrogen testing in a physician’s office or clinic.
The HydroStat Breath Hydrogen Tester is extremely easy to use. Any employee can be
trained to administer the test. No certification is required, and full training is provided
free of charge.
Breath hydrogen testing is typically reimbursable for various diagnosis codes, with the
most commonly used codes listed below. Coverage varies from state to state.
Therefore it is important to contact your local Medicare and Medicaid offices, and other
local insurance companies to determine which codes are excluded from the list below,
prior to doing to any testing.
ICD-9 Codes
Abdominal Bloating
Diarrhea:
Fermentative
Dietetic
Abdominal Pain
Flatulence, Abdominal Distention
CPT Code
Breath Hydrogen test (e.g. for detection of
lactase deficiency, fructose malabsorption,
5
787.3
787.91
787.91
789.0# (use fifth digit
based on site)
787.3
91065
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small intestinal bacterial overgrowth
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