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Intestinal Dysfunction Assays

Alterations in the bowel flora are now believed to be contributing factors to many chronic diseases such as allergies, autoimmune and inflammatory disorders, or degenerative diseases.

A number of factors such as antibiotic use, stress, certain dietary components, can have a detrimental impact on the gut microflora. Overgrowth of pathogenic bacteria results in the production of toxic bacterial compounds (such as endotoxins) which are absorbed into the bloodstream and cause abnormal immune activation. Gut inflammation, that may result from food intolerances or allergies, leads to an increased permeability of the intestinal wall (“leaky gut”), facilitating the passage of bacterial compounds to the blood.
Intestinal dysbiosis is very often found in CFS patients, and may significantly contribute to the development of the disease.

We use the following assays to investigate intestinal dysfunction:

  • IgA/IgM against intestinal bacteria
  • Lactase deficiency assay

A new, state of the art procedure for stool microbial population analysis is now available at RED Laboratories. Our metagenomics stool analysis provides a complete overview of bacterial populations present in a stool sample, including aerobes, anaerobes, and bacterial species which cannot be analyzed by traditional culture techniques. For more information visit the MSA test page.


The Immunobilan test is an antibody screening assay for antibodies (IgA and IgM) directed against antigens from intestinal pathogens. IgA are secreted from intestinal cells, IgM are produced by immune cells in the blood. In healthy individuals pathogenic bacteria are only found in low quantities in the gut, and antibody titers in the blood are very low. In case of bacterial overgrowth however, large quantities of IgA are produced and some IgA will be found in the bloodstream. In case of leaky gut, bacterial proteins may make their way to the bloodstream, and specific IgM will be produced. Therefore, high titers of IgM for intestinal bacteria is an indicator of increased intestinal permeability. All Immunobilan bacteria are strictly associated with the gut, with the exception of Klebsiella, which is also associated with respiratory and urinary tract infections.


Intolerance to lactose (dairy products) can lead to strong intestinal dysfunction. This relatively common condition (10-20% of the population in Northern Europe) has a genetic origin: a polymorphism in the gene coding for lactase, an enzyme responsible for the digestion of lactose (C/T-13910 polymorphism). In affected people, production of the enzyme declines during or shortly after childhood, resulting in lactose malabsorption. Undigested lactose sugars affect the development of gut microflora, leading to dysbiosis.

Two copies (alleles) of the lactase gene are present in the genome. Each allele can be either T-type (normal, production of lactase), or C-type (abnormal, lactase deficiency). A patient can have three possible genotypes:

- T/T: normal expression of the enzyme, patients are lactose tolerant.

- C/T: only one functional copy, however this is sufficient for lactose metabolism, therefore these patients can be considered lactose tolerant.

- C/C: these patients are lactase deficient, their tolerance to lactose is limited.