Fructose Intolerance Test

Why take a fructose intolerance test?

Complaints such as bloating, diarrhoea and stomach pain can have various causes. One possible cause could be fructose intolerance, an intolerance.

However, fructose is also found in many foods that contain many valuable nutrients, such as many types of fruit and vegetables. That is why it is not a good idea to cut fructose out of your diet if you suspect an intolerance.

If you experience regular digestive discomfort, you should ideally take a test to find out whether you really have an intolerance. With more certainty, you can then consciously change your diet in a healthy way.

How does the Fructose Intolerance Test work?

Fill a glass with 420 millilitres of apple juice (room temperature). Before you drink the apple juice, take a breath sample – and then four more, each at half-hour intervals.

To collect the samples, blow hard into a mouthpiece – it is connected to a sample bag. You then send the five breath samples to our specialised laboratory for analysis.

What do my results tell me?

The results report informs you of the concentration of hydrogen and methane in your breath. Values that have significantly increased indicate that the apple juice has triggered a reaction in your intestine, meaning that it is likely you are fructose-intolerant.

For people without an intolerance, fructose is broken down in the small intestine. With fructose intolerance, however, fructose reaches the large intestine, where methane and hydrogen, among other things, are then produced.

How long does the analysis take in the laboratory?

Once your sample has arrived at the laboratory, it will be analyzed there by specialists. How long the analysis takes depends on the exact measuring method and the processes in the laboratory.

If the sample is sent on the correct days (Sunday to Tuesday), this makes it easier for the laboratory to adhere to the times.

For the Fructose Intolerance Test, the laboratory analysis is usually completed within 5 working days after the sample is received in the laboratory.  

Which recommendations will I receive?

The results report gives you recommendations about which foods you should avoid from now on and how you can still ensure a sufficient intake of nutrients.

Changing your diet in three phases can help you in two ways – you can find out more specifically what you can tolerate and what you cannot. And you can gradually adapt your diet to your needs.

What leads to fructose intolerance?

Normally, fructose is absorbed in the small intestine before it can enter the large intestine. But if you eat too much food containing fructose, your digestive system may not be able to keep up, and fructose enters our large intestine, leading to discomfort. This is why too much fruit, for example, can cause stomach aches – even for healthy people.

For people with digestive fructose intolerance, however, even small amounts of fructose are enough to trigger symptoms. The transprotein GLUT-5 is not present enough in their intestines. As a result, fructose is not properly transported out of the small intestine and ends up in the large intestine. There, bacteria feed on the fructose, producing several byproducts. These byproducts include fatty acids, which greatly dilute stool, methane, which contributes to bad breath, and carbon dioxide and hydrogen gas, which cause bloating.

What are the signs of fructose intolerance?

Fructose intolerance is noticeable through digestive discomfort. If you have ingested fructose, symptoms usually appear within 30 minutes and can last up to nine hours.

Typical symptoms of fructose intolerance are:

• Flatulence
• Diarrhoea and vomiting
• Abdominal cramps
• Fatigue

What should I do if I am fructose-intolerant?

If you are diagnosed with fructose intolerance, you should first avoid fructose in your diet as much as possible. It is also better to leave out the sugar substitutes sorbitol and inulin for the time being. After that, you can come up with a long-term diet plan with a three-phase dietary change.

Fructose intolerance can be very restrictive. You should therefore make sure that your intake of sufficient vitamins and minerals is still optimal. Nutritional advice from an expert is usually recommended to ensure your diet remains balanced, nutritious and tasty.

Which foods contain fructose?

Fructose is found in many fruits and also in some vegetables and ready-made foods. Fructose is usually labelled as an ingredient on food packaging – sometimes as fructose or fructose syrup, for example.

The following foods are particularly rich in fructose:

• Apples, pears and kiwi
• Strawberries, raspberries and currants
• Dried fruit, especially apricots and dates
• Maple syrup, agave syrup and honey

Foods that contain both fructose and glucose, such as apricots, plums, bananas, lemons, avocados and potatoes, are often well tolerated. When you consume these foods, fructose passes out of the small intestine via the glucose transport proteins.

Who should NOT take the test?

The Fructose Intolerance Test is not or only partially suitable for certain groups of people:

• People with infectious diseases, like hepatitis and HIV, may not use the Fructose Intolerance Test.
• Pregnant and breastfeeding women should only take the Fructose Intolerance Test under medical supervision. The given reference ranges and recommendations do not apply to people in this group; consult your medical professional for advice concerning your test results.
• The Fructose Intolerance Test is not intended for children under 18 years of age.

The test is not intended for diagnosing illnesses or diseases. For example, if you suffer from chronic diarrhoea or extreme pain, consult a doctor.

Why are children under 18 not allowed to take the test?

Our tests are not suitable for underage children and adolescents under the age of 18. Under 18s cannot activate the tests online and therefore cannot receive a test result. We ask that you do not administer the tests to your children either.

Children and adolescents need much closer supervision and counselling regarding medical tests and their interpretation. Testing with lancets and chemicals is not without risk and would need to be closely supervised by guardians. In addition, the reference values we give are always based on adult data. In the case of children, the risk of misinterpreting the results would be very high.

We want to fulfil our responsibility as a provider of medical products and ensure that children and adolescents are not unsettled by measurement results that are difficult for them to interpret. Since we cannot control whether the minors' legal guardians actually consent to the test being carried out and supervise them, we exclude tests for under 18s altogether.

If you are under 18 and have purchased a test, please contact our customer support.