242 Diet Wise
stool. Bile acid deficiency and bacterial overgrowth usually do not produce
fecal fat of more than 30 gm per day. Patients with celiac disease will rarely
produce more than 60 gm of fat per day in the stool. Severe steatorrhea (80
- 100 gm of fat per day) is seen in patients with pancreatic insufficiency or
in patients who have had large chunks of bowel removed.
The D-xylose test is a very useful test to evaluate the integrity of
the intestinal mucosa and its ability to absorb. D-xylose is a sugar that is
absorbed across the intestinal mucosa and can be measured in the urine and
blood. After a patient drinks the Xylose, urine or blood are collected over
the next several hours. Low Xylose levels in the blood or urine are highly
suggestive of a abnormality of the intestinal mucosa.
Pancreatic function tests are more elaborate but could add value
in difficult cases. A tube is placed through the nose or mouth so that its
tip is lying next to the opening of the pancreatic duct into the duodenum.
Secretions are collected and the content of bicarbonate and enzymes are
measured after the pancreas has been stimulated with a hormone called
secretin or with a test meal. Pancreatic insufficiency is indicated if the
bicarbonate and enzyme concentrations are very low.
Another pancreatic function test, the Bentiromide test, involves
ingestion of a chemical called bentiromide. This is broken down by
pancreatic enzymes and one constituent (para-aminobenzoic acid, PABA)
is absorbed and excreted in the urine. Pancreatic insufficiency is suspected
when urinary PABA levels are low.
[Medical University of South Carolina website: http://www.ddc.musc.edu/ddc_
pub/index.htm
Leaky gut syndrome
Finally, a third model of intestinal health and disease, concerning the way
food residues are dealt with by the gut.
It is important to realize that the contents of the bowel are technically
outside the body. If you imagine a piece of string entering at the mouth and
emerging from the anus, you will readily see this is true. The defined space
of the bowel (or lumen) contains a considerable immunological and toxic
burden, including potentially allergenic food residues, waste toxins, food
toxins (both natural toxins and artificially added man-made chemicals),
bacteria, parasites and free radicals released by many processes taking place.
Precisely because of our very intimate entanglement with this space, our
bodies need to be protected from these deleterious substances.