INTRODUCTION
Lactose intolerance occurs in the case of a partial or total deficiency of the enzyme lactase, which is capable of breaking down lactose, the primary sugar in milk, which is also present in other dairy products or derivatives.
Symptoms arise from 1-2 hours to a few hours after the ingestion of foods containing lactose, and those that most characterize lactose intolerance are as follows:
- Abdominal pain
- Nausea
- Headache
- Abdominal bloating
- Diarrhea or constipation
- Fatigue
- Skin rashes
- Meteorism, flatulence
However, these symptoms are not specific but common to other similar disorders. Furthermore, it is important to specify that it differs from patient to patient, with manifestations of varying intensity depending on the degree of lactase enzyme deficiency.
Under normal conditions, lactose (a disaccharide consisting of glucose and galactose) is digested in the small intestine by an enzyme, lactase, which releases the two monosaccharides, which are then absorbed in the small intestine. The monosaccharides are transported to the liver where galactose is converted with high clearance into glucose, which undergoes oxidation to CO2, which is eliminated in the breath.
In the case of lactose intolerance, the partial/total lack of lactase does not allow for the absorption of lactose, which passes into the gastrointestinal tract, causing distension.
THE TWO TESTS
Until a few months ago, only one type of Breath Test existed, or was at least widespread, for the diagnosis of lactose intolerance: the H2 Breath Test, or Hydrogen test for lactose intolerance.
We will cover this test in the second part of the article, while in this first part we present the innovative C13 Breath Test, or Carbon test for lactose intolerance.
There is a reliable method to determine if you are lactose intolerant, and it is called a Breath Test. I can say from personal experience: it is not pleasant!
It is not pleasant for lactose-intolerant people because the test involves taking a quantity of lactase dissolved in a glass of water on an empty stomach—equal to 30 grams (for adults) for the Hydrogen test and 15 grams for the Carbon test.
It is clear to everyone that a person intolerant to a product who consumes that product will not have a comfortable reaction (LINK to common symptoms). Having a bathroom nearby for the entire duration of the test is therefore essential. The more lactose you consume, the more you will feel the discomfort associated with the intolerance.
What kind of timeframes are we talking about? The duration of the test is 4 hours for the H2 version and 2 hours for the C13 version.
Do you need to arrive on an empty stomach? Yes, for the H2 test you must abstain from food for 8 hours before the test, for the C13 only 3.
So the Carbon test already has 3 advantages over the Hydrogen test: it lasts less time and you have to consume less lactose (less suffering).
This is also why we support and have introduced the new C13 Breath Test on our e-commerce site, in a format that can be easily carried out at home, where we have our favorite bathroom and the assistance of our loved ones.
CARBON BREATH TEST
C13 Breath Test for lactose intolerance
Lactose intolerance now has a new ally: the revolutionary Carbon test to discover the condition of lactose intolerance.
This test is faster, simpler, less "painful," and can be done at home. It is so innovative that we at Lactosolution wanted to offer it to our customers through our website's e-commerce.
It is a breath test based on the oral administration of lactose labeled with the stable, non-radioactive 13C isotope. It is a direct and semi-quantitative method in which the increase in the 13CO2/12CO2 isotopic ratio measured in the breath is directly correlated to the amount of lactose metabolized and absorbed, and therefore to the activity of the lactase enzyme.
The amount of lactose is lower compared to the hydrogen breath test (15 grams versus 25 grams), which allows for fewer disturbances associated with the test.
The test has a low degree of invasiveness and a high degree of safety: it can also be used in pediatric patients (Amarri, 1999; Casellas, 1999) and in pregnant women. The 13C lactose breath test is a more direct method than the hydrogen test, as it gives a measurement of the amount of glucose and galactose absorbed (not the hydrogen emitted due to lack of lactose absorption), and is therefore safer and more precise.
This test, compared to others, is less subject to interference from other pathologies and to false positives in patients with bacterial overgrowth or false negatives in patients defined as “non-H2-producers.”
The novelty also lies in doing it at home. You will no longer have to wait to blow in front of the diagnostics laboratory door, whether at the hospital or clinic; instead, you will be comfortably seated at home... just a few steps from your favorite bathroom!
How does the Carbon 13 exam for lactose intolerance work?
The procedure is similar to that of the Hydrogen Breath Test. That is, you must exhale into a machine that detects the Carbon isotope at regular time intervals, intervals that will be indicated by the assistant or in the package.
Specifically, the machine will be able to understand the metabolization rate of the 13C substrate, expressed in dose/h(%).
After the first breath, the value of which will be called the baseline value, you must consume a quantity of lactose with a percentage of C13-labeled atoms* in liquid form (powder dissolved in water).
*13C lactose is prepared according to a natural process that involves feeding cows corn, separating the lactose from the milk, and freeze-drying. Corn, unlike other plants, has a C4-type photosynthesis metabolic cycle, which determines the preferential use of 13C-labeled molecules compared to 12C, resulting in enrichment. There is no need to be afraid of Carbon-labeled lactose!
The analysis for determining the presence of C13 elements in our breath can be performed using mass spectrometry (IRMS) or infrared spectrometry (IR), which are two different machines that produce the same result.
The values analyzed by the instrument will then be displayed in a graph that can indicate our intolerance condition.
In this graph, we will have time on the abscissa axis (X-axis) and the metabolization rate of the 13C substrate on the ordinate axis (Y-axis), expressed in dose/h(%). This data is called cDPR.
With the C13, when am I lactose intolerant?
A cDPR value greater than or equal to 5 dose/h(%) means that the subject has normal lactose absorption and is therefore not lactose intolerant.
A value of less than 5 dose/h(%) means that the subject has lactose malabsorption and is therefore lactose intolerant.
Unlike H2 tests, in this case, to be intolerant, one must not exceed a certain threshold.
Let’s now look at a couple of examples of real tests found on the web. The first results positive for lactose intolerance, the second negative.
The C13 test at home
If you choose the “test at home” solution, once you open the package you will find a small jar with the lactose powder, some test tubes, and instructions.
The test is simple, and the provided and updated instructions will show you the steps to follow.
Normally, as we have already seen, you must first exhale (blow) into 2 of the 6 provided test tubes, then prepare the drink with the lactose powder (15 g of lactose + 200 ml of water) and drink it. The procedure concludes by exhaling (blowing) every 30 minutes into one of the remaining test tubes until all are finished (2 hours).
Once the material is ready, a simple WhatsApp message is enough to have the test collected directly from your home, in its original packaging. All that remains is to wait for the arrival of the results, which will be sent to your email address within a maximum of 15 days.
Do we need to prepare ourselves to face the Carbon test?
For the test to be valid, it cannot be performed under certain conditions, which leads to the following simple but important rules:
Before the test:
For maximum reliability of the test, the patient:
- Must fast for at least 3 hours; they can only drink still water.
- Must not smoke, sleep, or do intense physical exercise for at least half an hour before and during the test.
- Should not take medications, as some may have consequences on the test result.
- Must not take probiotics (lactic ferments) for at least a week.
During the test:
- Avoid physical exertion;
- Fast (small amounts of water are allowed);
- Do not leave the test location (you are called every 30 minutes if done in a hospital);
- Prepare for any abdominal pain and diarrheal episodes.
After the test:
After completing the test, you can resume all daily activities, including your preferred diet. As with the Hydrogen test, in the first few hours after the test, lactose intolerance symptoms might continue to manifest, with the need to use the restroom frequently.
Purchase link: Breath Test C13
HYDROGEN BREATH TEST
H2 Breath Test for lactose intolerance
The test lasts a long time because, at 30-minute intervals, the amount of Hydrogen (H2) present in the breath is measured with a specific instrument called a gas chromatograph.
Why hydrogen?
In intolerant people—that is, those who, for genetic reasons or due to external factors, lack the enzyme that should metabolize it—lactose ferments in the colon, creating some easily recognizable gases, including hydrogen (H2). The latter enters the bloodstream and, through the circulatory system, reaches the lungs where it is exchanged with the breath air.
During the test, you will in fact have to exhale air into a mouthpiece or a bag connected to the measuring instrument, which will be able to indicate the amount of hydrogen detected in the breath.
This amount, expressed in parts per million (ppm), is plotted on the ordinates of a graph, which has time as its base (abscissa).
The evolution of the amount of Hydrogen over time, compared with the initial value—before lactose intake, also called the baseline value—tells us if, and how much, you are lactose intolerant.
With the H2, when am I lactose intolerant?
An increase in gas production greater than 20 parts per million (ppm) compared to the baseline value (the red line below, varies from person to person), after lactose ingestion, indicates that the subject is lactose intolerant.
Finally, based on the amount of H2 produced, lactose intolerance can be described as mild, severe, or moderate.
Let's look at some example trends and values:
(values are to be understood as a mere example and are in no way binding; it is interesting to observe the deviation from the personal limit value or from the baseline value + 20 ppm shown in red)
Mild lactose intolerance
Moderate lactose intolerance
Severe lactose intolerance
No lactose intolerance
The red line shown above to improve data understanding will not be present in the graphs that will be provided to us as test results (sometimes not even the graph is present, only the numerical values). This can be derived mentally by simply adding "20" to the first value obtained during the test (baseline value). Red line = baseline value + 20.
Let’s now look at a couple of examples of real tests found on the web, both positive for intolerance:
Do we need to prepare ourselves to face the hydrogen test?
For the test to be valid, it cannot be performed under certain conditions, which leads to the following simple but important rules:
Before the test:
- Fast for at least 8 hours and avoid, in the 24 hours preceding the exam, milk, dairy products, and all food products that may contain lactose (water is permitted; only MEAT, FISH, and RICE are recommended);
- Avoid taking antibiotics in the 15 days before the exam;
- Avoid taking laxatives and probiotics (lactic ferments) in the 7 days before the exam;
- Avoid tobacco use for at least 8 hours;
- Do not have ongoing intestinal pathologies or have recently had invasive colon exams;
- Limit the intake of cane sugar, cornflakes, corn derivatives, peanuts, peas, and fiber-rich foods in the 24 hours preceding the exam.
During the test:
- Avoid physical exertion;
- Fast (small amounts of water are allowed);
- Do not leave the test location (you are called every 30 minutes);
- Prepare for any abdominal pain and diarrheal episodes.
After the test:
After completing the test, you can resume all daily activities, including your preferred diet. In the first few hours after the test, lactose intolerance symptoms might continue to manifest, with the need to use the restroom frequently.
CONCLUSIONS
In summary, the Breath Test is a non-invasive and affordable exam approved by the scientific community and offered by major hospital facilities to investigate the ability to digest lactose. It rarely returns false positives, but be careful: a positive result indicates our current intolerance condition, but does not indicate whether we will also be in the future.
As you can read in our guide, in fact, lactose intolerance can also be transient and due to temporary malfunctions of our internal system.
The innovative C13 Breath Test for lactose intolerance is even simpler and faster and is currently the reference exam for diagnosing the presence of milk and dairy intolerance (let's remember that it is not a milk or lactose allergy). It can be performed at home in complete safety and guarantees an excellent result.
On the other hand, a genetic test (DNA Test for lactose intolerance) can tell us if we are genetically predisposed (now or in the future) to lactose intolerance, even if it doesn't tell us when we will become so. In the presence of symptoms of lactose intolerance, the DNA Test is also a valid exam for diagnosing the condition of lactose intolerance.
The sum of the two tests (Breath Test + DNA Test) ensures a complete picture regarding our lactose intolerance conditions. If you want to know about the genetic test for lactose intolerance, click here.
Are you scared of a positive intolerance result?
Or are you already tired of being lactose intolerant? Thanks to the Lactosolution 15000 lactase supplement, the solution is at your fingertips.
Click here to try the revolutionary dietary supplement specifically for lactose maldigestion, or study the functioning of the lactase enzyme here.
Purchase link: Breath Test C13.
Bibliography
- Excellent agreement between genetic and hydrogen breath tests for lactase deficiency and the role of extended symptom assessment. Pohl D, Savarino E, Hersberger M, Behlis Z, Stutz B, Goetze O, Eckardstein AV, Fried M, Tutuian R. Br J Nutr. 2010.
- Adult-type hypolactasia genotyping in Northern Italy: prevalence of C/T-13910 polymorphism and questions after comparison with existing data. Ghidini C, Sottini A, Zanotti C, Serana F, Marini M, Caimi L, Imberti L. Minerva Gastroenterol Dietol. 2010
- Effect of C/T -13910 cis-acting regulatory variant on expression and activity of lactase in Indian children and its implication for early genetic screening of adult-type hypolactasia. Kuchay RA, Thapa BR, Mahmood A, Mahmood S. Clin Chim Acta. 2011
- Meta-analysis: the diagnostic accuracy of lactose breath hydrogen or lactose tolerance tests for predicting the North European lactase polymorphism C/T-13910. Marton A, Xue X, Szilagyi A. Aliment Pharmacol Ther. 2012
- Analysis results provided by Google and friends
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