Diagnosis

The diagnosis should always begin with a detailed and thorough anamnesis (taking the patient’s medical history). In the case of complaints affecting the gastrointestinal tract, a travel anamnesis (question about stays abroad) is also useful. A physical examination can then provide valuable information about the underlying disease and decide which tests and further measures can be usefully supplemented afterwards.

Various stool and blood tests can confirm or disprove the corresponding diagnosis. If a Leaky Gut Syndrome is suspected, a stool examination can be performed first. On the one hand, the presence of pathogenic (disease-causing) intestinal germs such as Clostridium difficile, shigella, etc.

is tested. On the other hand, an examination of the intestinal microbiome (the “intestinal flora“) takes place. Here the ratio of the different intestinal germs is determined, i.e. whether there are enough “good/healthy” types of bacteria.

In addition, if food intolerances are suspected, appropriate targeted tests should be carried out, for example an H2-lactose breath test in case of lactose intolerance. If there are indications of an underlying inflammatory process in the intestine, calprotectin in the stool can be useful as a marker. Blood tests for so-called “inflammation parameters” such as the CRP (C-reactive protein), the number of leukocytes or a BKSG (blood cell sedimentation rate) can also be helpful.

A specific test for increased intestinal permeability is the lactulose mannitol test. The basis for this test is that both sugars are not metabolized and can therefore be measured unchanged in the urine of healthy persons. While mannitol is absorbed through the cells, lactulose is absorbed paracellularly, i.e. between the cells.

In the Leaky gut syndrome, it is primarily the terminal strips that are affected and limit the transport between cells. Therefore, lactulose appears more in the urine of affected individuals than mannitol.The quotient of lactulose and mannitol in the urine after drinking a solution containing both substances is thus significant for a disturbance of the permeability of the intestine. In addition, secretory immunoglobulin A in the stool can also be determined. It is produced by the plasma cells in the intestine and is primarily responsible for the defence on mucosal surfaces. All of the above tests should be performed by all means depending on the symptoms and after consultation with a physician regarding the necessity.