The Leaky GUT Test


The Leaky Gut test is a unique and comprehensive test to determine increased intestinal permeability ('leaky gut'), damage to the lining of the intestines, gut function, lactose intolerance, sucrose intolerance, and the health of intestinal villi on the gut lining. 

More info

The theory behind the Leaky Gut test has been comprehensively reviewed, and by evaluating the past 30 years scientific literature, it is now possible to obtain a more in-depth understanding of intestinal function.

This Leaky Gut test provides an indication as to whether a patient suffers from one or more of the following clinical conditions: reduced absorption capacity; increased gastrointestinal permeability; inflammation; or lactose and sucrose intolerance – knowledge not previously obtainable from the two sugar tests. The test is carried out following the ingestion of a sugar solution containing the different types of sugar: mannitol, sucrose, lactose and cellobiose. The concentrations of the different sugars are identifiable in urine. The levels or their mutual ratios indicate whether the above clinical conditions are prevalent.

Increased Intestinal Permeability 

Increased intestinal permeability syndrome ('Leaky Gut') is a condition caused by damage to the mucosal lining of the intestines. The intestines are designed to absorb nutrients as small molecules. When the bowel lining is altered or damaged, larger, undigested molecules are absorbed into the bloodstream and cause an immune reaction and further inflammation, consequently hampering the absorption of beneficial nutrients.

Increased intestinal permeability is primarily caused by overconsumption of alcohol, carbonated drinks, pharmaceutical drugs, and diets consisting of low-fiber, high-fructose, preserved, gluten, dairy, food allergies and sensitivities, and processed foods.

The effects can be varied and severe, ranging from fatigue and bloating to heightened food allergies, protein damage, detoxification inhibition, and a weakened immune system. Unfortunately, many of these symptoms are unrecognised, and many cases of increased intestinal permeability are undiagnosed.

Benefits | Features

  • Unlike many other Leaky Gut tests, this test analyses five types of sugar and their corresponding enzymes as opposed to only two
  • Tests that only use 2 two sugars show two-fifths of the clinical picture

Tests for

Intestinal permeability or a 'leaky gut'.

Who would benefit from this test?

Anyone with 1 or more of these symptoms or conditions:

  • Abdominal discomfort
  • Bloating
  • Coeliac disease
  • Crohn's disease
  • Constipation
  • Diarrhoea
  • Eczema
  • Fatigue
  • Food allergies and intolerances
  • Gas
  • Irritable bowel syndrome, including bloating, rumbling and flatulence
  • Migraine
  • Nutrient deficiency
  • Reiter's syndrome
  • Rheumatoid arthritis, joint and muscle pain
  • Schizophrenia and autism
  • Ankylosing spondylitis

      Contributing | Causal factors

      Possible causes of increased intestinal permeability:

      • NSAIDs
      • Antibiotics
      • Intestinal tract infections
      • Bacterial overgrowth and dysbiosis
      • Food reactions to, for example, gluten or dairy
      • Chemotherapy and radiation damage

        Pair with these tests

        Based on your symptoms and your results of the Leaky Gut test, you may want to do a follow-up test to obtain a clearer picture of a possible cause of your symptoms.

        Other tests you could consider:

        • Comprehensive Stool Analysis + Parasitology  

        This test identifies imbalanced intestinal flora such as bacteria, fungus and parasites. It also provides information on the pancreatic production of enzymes, and whether faecal protein and fat levels are too high, which may be an indication of low production levels of gastric acid and/or bile. Furthermore, the test reveals any elevated inflammation markers related to micro-inflammation, Crohn's disease, colitis and levels of sIgA and short-chain fa y acids. This test combined with the IPA test provides a comprehensive overview of function throughout the gastrointestinal tract.

        • Organic acids

        This test provides an insight into a wide variety of nutrition-related metabolic processes in the body, e.g. problems with detoxification, oxidative stress and, specifically, whether the pa ent has a dysbiosis (fungal and bacterial overgrowth in the small intestine). It is this dysbiosis which may be implicated in the function of the small intestine and is therefore advisable if the IPA test reveals abnormalities. 

        Test analytes

        Raffinose/mannitol ratio
        Lactose/raffinose ratio
        Sucrose/raffinose ratio

        More info about the analytes

        • Mannitol level - a measure of intestinal absorption capacity

        Mannitol is a sugar alcohol and has a small molecular size.

        Under normal conditions, it is easily absorbed in the upper part of the small intestine through the epithelial cells, via the small pores in the brush borders (passive diffusion). Once absorbed, it can be found in urine.

        When the absorption of mannitol is suboptimal, it will not be found in the urine. This is an indication the gut lining has a reduced absorption capacity. This can indicate that the intestinal uptake of important nutrients is also hindered, which could ultimately lead to vitamins and minerals deficiencies.

        • Cellobiose level - a measure of intestinal permeability

        Cellobiose is a disaccharide consisting of two glucose molecules. Cellobiose is not broken down by the enzymes in the gastrointestinal tract.

        Under normal conditions, it will not be absorbed and will, therefore, not be found in urine. Instead, it will pass through to the large intestine, in which it serves as a substrate (food) for the beneficial intestinal flora.

        However, if cellobiose is found in the urine, it means that it has been absorbed through the lining of the intestines. This shows that the intestinal mucosa is damaged and that the gut is 'leaky'. This increased intestinal permeability could ultimately lead to increased absorption of unwanted toxic substances and molecules, including food. If food is absorbed in a partially broken down form, it can enter the blood cause an immune response. Among other things, this can lead to various autoimmune diseases. 

          • Sucrose level – a measure of gastric permeability

          Sucrose, also known as white table sugar, is a disaccharide consisting of glucose and fructose. In the duodenum (small intestine), it is broken down by the small-intestinal brush border enzyme, sucrase.

          Under normal conditions, sucrose is not traceable in urine. However, if sucrose is detected in the urine, it may indicate a leaky gut caused by irritation or mucosal inflammation.

          • Raffinose/mannitol ratio - a measure of damage to the small intestine


          Raffinose is a trisaccharide consisting of galactose, fructose and glucose. Raffinose is not broken down by enzymes in the gastrointestinal tract.

          Under normal conditions, it will not be found in urine. It should pass straight through to the large intestine, where it serves as a substrate (food) for the intestinal flora.

          However, if raffinose is absorbed via passive diffusion, it will be found in urine. This indicates a reduced capacity in the tight junctions and possible intestinal inflammation.

          More raffinose than mannitol is an indication of damage to the epithelial tissue in the duodenum, possible intestinal inflammation, and a leaky gut.


          As mentioned above, mannitol is a small sugar molecule, the absorption of which is limited in cases of intestinal inflammation or damage, as in coeliac disease or Crohn’s disease.

          • Lactose/raffinose ratio – a measure of lactose intolerance

          Lactose is a disaccharide which is broken down into galactose and glucose (in the small intestine, primarily the jejunum) by the brush border enzyme lactase.

          Under normal conditions, lactose will not be found in urine.

          If lactose is found in the urine, it means there is not enough lactase in the small intestine to break down lactose properly. This can lead to increased intestinal permeability or a 'leaky gut'.

          More lactose than raffinose indicates a lactose intolerance.

          • Sucrose/raffinose ratio – a measure of sucrose intolerance

          The ratio between sucrose and raffinose is interpreted in comparison to the lactose/raffinose ratio.

          More sucrose than raffinose is an indication of low activity of the digestive enzyme sucrase (in the small intestine, primarily the duodenum) and of a sucrose intolerance.  

          More raffinose than sucrose, can indicate that there is intestinal damage lower down in the intestines.

          Test sample report

          Test sample type

          Urine sample

          Processing time

          About 2 weeks

          Lab's name for test

          Intestinal Permeability & Absorption (IPA) test