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.