Intestinal Permeability Assessment

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Turnaround Time: 7 days
Test Type: Kit Based, Urine


Intestinal Permeability Assessment is a powerful noninvasive gastrointestinal test assessment of small intestinal absorption and barrier function in the bowel. The small intestine uniquely functions as a digestive/absorptive organ for nutrients as well as a powerful immune and mechanical barrier against excessive absorption of bacteria, food antigens, and other macromolecules. Both malabsorption and increased intestinal permeability ("leaky gut") are associated with chronic gastrointestinal imbalances as well as many systemic disorders.

Increased intestinal permeability (leaky gut) of the small intestine can:

• Increase the number of foreign compounds entering the bloodstream

• Allow bacterial antigens capable of cross-reacting with host tissue to enter the bloodstream, leading to auto-immune processes

• Enhance the uptake of toxic compounds that can overwhelm the hepatic detoxification system and lead to an overly sensitized immune system

Leaky gut has been observed in a range of disorders such as:

• Inflammatory Bowel Disease (IBD)

• Food allergy • Inflammatory joint disease

• Chronic dermatologic conditions

Studies have demonstrated that the increased intestinal permeability observed in patients with ankylosing spondylitis, rheumatoid arthritis, and vasculitis may be an important factor in the pathogenesis of these disorders.

Decreased permeability, on the other hand, appears as a fundamental cause of malabsorption, subsequent malnutrition, and failure to thrive. In certain disease states of the small intestine, such as gluten-sensitive enteropathy, permeability to large molecules may increase while permeability to small molecules decreases - a result of damage to the microvilli. As a result, nutrients become even less available to assist in the detoxification of antigens flooding the system.

Possible causes of increased intestinal permeability (leaky gut) include:

• Intestinal infection • Ingestion of allergenic foods or toxic chemicals

• Deficient secretory IgA

• Trauma and endotoxemia


The Intestinal Permeability Assessment gastrointestinal test directly measures the ability of two non-metabolized sugar molecules to permeate the intestinal mucosa. The patient drinks a premeasured amount of lactulose and mannitol. The degree of intestinal permeability or malabsorption is reflected in the levels of the two sugars recovered in a urine sample collected over the next 6 hours.

Collection Details:

Collection Instructions:

1.     After your overnight fast (of at least 8 hours), collect your first morning urine in the small plastic cup. (Note: If you wake up to urinate during the night within six hours before your rising time, collect your urine and refrigerate it; then add that refrigerated sample to the urine you collect when you rise for the day.)
2.     Using the pipette, fill the white-top tube to 1cm below the top of the tube with the urine collected in Step 2. Screw the cap tightly on the tube and invert several times. Write your name, the time, and date of collection on the tube label. Place tube in Biohazard bag and refrigerate. Discard remaining urine and pipette. Rinse collection cup and let air-dry.
3.     Open the Lactulose/Mannitol drink mix. Fill bottle up to the fill line with water. Replace bottle lid and close bottle. Mix drink by shaking bottle vigorously.
4.     Drink all the Lactulose/ Mannitol solution.
5.     Note the time here: _______________
6.     Collect all of your urine for six hours after taking the test drink. Use the small plastic cup to collect your urine and pour it into the large container. Keep refrigerated.
7.     Five to six hours after drinking the test drink, collect a final urine sample and pour it into the large container. (Note: Do not collect any urine after the 6 hour time frame. Doing so may compromise the test results.)
8.     Cap the container securely. Place the container on a flat surface and read the amount of urine in the container.
9.     Write the total amount of urine in the container on the requisition form in the space labeled “Total Urine Volume.” The analysis cannot be completed without this information.
10.     Make sure cap is on tight and shake large container vigorously at least 10 times to mix urine with sugars that settle to the bottom.
11.     Using the other pipette, fill the purple-top tube to 1cm below the top of the tube with urine from the large collection container. Tightly screw cap on tube and invert several times. Write your name, the time, and date the specimen was collected on the tube label. Discard the pipette, the remaining urine, and the large container. Place tube in the biohazard bag and keep the tubes refrigerated until shipment.
12.     Place refrigerated tubes in biohazard bag inside the flexfoil pack with frozen Gel Freezer Pack just prior to shipping.