Histamine stool test – histamine in stool for histamine intolerance

Histamine is a messenger substance produced in the body and found in foods such as aged cheese, wine or fermented vegetables. In the gut, bacteria also form histamine from the amino acid histidine. Histamine from food is mainly broken down by the enzyme diamine oxidase (DAO) in the intestinal lining (PubMed 33921522).

A raised value in stool shows that there is a lot of histamine in the gut, for example from food, from histamine-producing bacteria or from reduced breakdown. The value alone does not show which source is responsible. The measurement of histamine in stool has been little studied scientifically; the report states the laboratory's reference range.

No, this cannot be concluded from it. Histamine intolerance describes an imbalance between histamine taken in and the ability to break it down (PubMed 17490952). The stool value is a snapshot of the amount of histamine in the gut; it also depends on what you ate in the days before. This is why you should not eat an unusually histamine-rich meal before the sample: the value should reflect your everyday life.

Histamine in blood fluctuates strongly and over short periods. A review describes histamine intolerance as a disorder that arises mainly in the gut (PubMed 33921522). The stool test therefore measures the amount of histamine where histamine from food and bacteria accumulates.

To be honest: neither a stool value nor a blood value can prove histamine intolerance on its own. The German guideline considers laboratory values not conclusive enough for this question (PubMed 34651098).

There is no generally defined normal value for histamine in stool; each laboratory states its own reference range for its method. In our partner laboratory's sample report, the value in ng/ml is shown next to the laboratory's reference range (there “below 959 ng/ml”). If your value lies outside it, this is a measurement to be interpreted in the context of diet, symptoms and previous findings.

Histamine intolerance refers to more histamine reaching the body than can be broken down. The balance between intake and breakdown is disturbed, and complaints resembling an allergic reaction can occur (PubMed 17490952). Unlike an allergy, the immune system is not involved.

The condition is controversial: one review is titled “the more we know the less we know”, because symptoms in the same person differ after similar triggers (PubMed 34209583).

The main cause is considered to be reduced activity of diamine oxidase (DAO) in the gut. A review names diseases of the intestinal lining and certain medications as possible reasons for lower DAO activity (PubMed 33921522). Alcohol and medications that release histamine or block DAO can favour symptoms (PubMed 17490952). Other reviews also mention genetic factors (PubMed 38674909).

If you take medication regularly, do not stop it on your own; talk to your doctor.

There is no single laboratory test that reliably proves histamine intolerance. The guideline of the German-speaking allergy societies describes a practicable approach to diagnosis and treatment; it considers measuring DAO in blood not conclusive (PubMed 34651098). Another review describes the assessment as time-consuming and multidisciplinary (PubMed 34209583).

The histamine stool test is therefore a measurement that can feed into this assessment, not proof. If you also want to know how active the breakdown enzyme is, there is the histamine and DAO analysis.

Some gut bacteria can produce histamine. In a study in mice, histamine produced by gut bacteria increased the pain sensitivity of the gut (PubMed 35895832). Whether this applies to humans is still open. Reviews increasingly view histamine intolerance as a disorder that originates in the gut (PubMed 33921522).

This test does not show whether histamine-producing bacteria are present; stool profiles with gut flora analysis are available for that.

Research describes very different complaints in histamine intolerance, often after histamine-rich meals or alcohol; the evidence varies in strength:

• Bloating, abdominal pain, fullness and diarrhoea: in an evaluation of people with suspected histamine intolerance, bloating was the most common and most severe symptom; observed in studies (PubMed 30836736).
• Headache: described in reviews (PubMed 17490952).
• Flushing, itching and hives: described in reviews (PubMed 17490952).
• Runny or blocked nose, asthma-like symptoms: described in reviews (PubMed 17490952).
• Palpitations, heart rhythm disturbances and low blood pressure: described in reviews (PubMed 17490952).

These complaints are non-specific and vary greatly even in the same person (PubMed 34209583). The German guideline points out that symptoms often cannot be reproduced in provocation tests (PubMed 34651098). Allergies and other illnesses are also possible causes.

These are associations from studies, not causes in an individual person. The test cannot explain symptoms and does not provide a diagnosis. Persistent symptoms should first be assessed by a doctor.

If you have difficulty breathing, swelling of the face, lips or tongue, circulatory problems or fainting after eating, call the emergency number 112 immediately. If you have blood in your stool or black stool, unintended weight loss, fever, diarrhoea at night, severe or new abdominal pain, persistent vomiting or difficulty swallowing, the first step is a doctor’s practice, not a self-test. The same applies to new palpitations or a racing heart.

Complaints after certain foods may be a food allergy; this belongs in an allergy assessment. A stool test does not replace bowel cancer screening.

This page does not give treatment advice. Whether a result means anything at all and which steps make sense depends on your whole situation: symptoms, previous findings, medication and diet. The German guideline warns against restricting the diet unnecessarily strictly for years and recommends a professionally supported, personal approach (PubMed 34651098).

What makes sense for you belongs in a conversation with the ORY expert team or with your doctor or naturopath, for example from the ORY expert network. The results consultation is included in the price.

Before taking the sample, do not eat an unusually histamine-rich meal, for example aged cheese, red wine or fermented vegetables; the value should reflect your everyday life. Do not take the sample during menstruation, and postpone it if you have acute gastrointestinal complaints or a bleeding haemorrhoid. Ideally take the sample in the morning.

The stool must not come into contact with toilet water, as this distorts the histamine value; a stool catcher is included for this. Insert the dosing stick into the stool at three points and put it back into the tube only once. Do not send on a Friday or before public holidays.

The analysis usually takes 7–21 days from the time the sample arrives at the laboratory. You will be notified as soon as your report is ready. The results consultation with the ORY expert team is included in the price.

The histamine stool test costs €55 including VAT, shipping, return shipping within Germany and the results consultation.

Statutory health insurance in Germany does not usually cover stool analyses that you order yourself. With private insurance, reimbursement may be possible; the process is described under “Reimbursement by private insurance”.

The histamine stool test (€55) measures only histamine in stool. The histamine and DAO analysis (€93) adds the activity of the breakdown enzyme DAO in dried blood. The basic gut profile (€285) and the gut profile microbiome & gut barrier (€315) combine histamine with gut flora and the gut barrier. For milk or fruit sugar there are the lactose breath test and the fructose absorption analysis (€65 each).

Which test makes sense for you can be clarified in the free initial consultation.