Leaky Gut

Leaky Gut Assessment
Testing Intestinal Permeability with Lactulose-Mannitol Challenge


Lactulose-Mannitol Urine Test

Leaky Gut can be assessed through the Lactulose/Mannitol test. The two different sized sugar molecules are excreted in the urine which reflects absorption from the gut and is a reliable representation of gut permeability. The smaller molecule (mannitol) freely crosses the gut barrier and is a general measure of small intestinal surface area; while the larger molecule (lactulose) is thought to only cross through the small intestine if pores are enlarged or cells are damaged.

To assess intestinal permeability, lactulose and mannitol excretion is recovered in urine. Variations in transit time in the intestine and renal clearance are normalized through the use of a ratio calculation which reflects the proportion of large to small sugars. This ratio is the researched criteria for assessing suspected intestinal permeability. It is important to note that the accuracy of the results is dependent on patient adherence to test preparations and instructions as well as normal renal function.

What is Leaky Gut?

Leaky Gut describes a condition in which the lining of the small intestine becomes damaged, causing undigested food particles, toxic waste products, and bacteria to penetrate and enter the bloodstream. These foreign substances invading the bloodstream can cause autoimmune responses, including inflammatory and allergic reactions. These agents can cause local and systemic reactions associated with a broad range of diseases.

In addition to Leaky Gut’s role in “letting the bad things in” it also the culprit for keeping out the good; in the form of damaged cells which cannot adequately produce the substances necessary to aid in digestion of nutrients. A failure in the quality of nutrient intake is at the root of a myriad of health problems, including those which impact hormone balance and brain function.

Common Conditions Related to Leaky Gut

Sample Leaky Gut Report
  • Chronic constipation, diarrhea, or gas
  • Weak immune system
  • Headaches
  • Excessive fatigue
  • Depression or anxiety
  • Skin rashes and problems such as acne or eczema
  • Brain fog, memory loss
  • Arthritis or joint pain

Leaky gut can be caused by damage from autoimmune reactions, such as gluten (gliadin) intolerance which destroys the mucosal layer, opens up tight junctions, and increases permeability. It can also be damaged by bacterial toxins related to Small Intestinal Bacterial Overgrowth (SIBO), which contributes to intestinal barrier inflammation.

Additionally, leaky gut can be caused by food sensitivities with the immune system activity in which white blood cells mount attack on undigested food particles. Stress – chronic and acute – will also contribute to a general lack of healthy gut balance.

What Makes BioHealth’s Lactulose-Mannitol Testing Superior?

Peak Excretion Measurement: We’re testing peak excretion and representing the “suspected intestinal permeability” interpretation based on the ratio at this time point. The ratio is in place to account for variations in gastric emptying, intestinal transit, renal clearance, and incomplete urine recovery which are factors that affect the lactulose and mannitol equally.

Test Method: Advanced testing methodology of liquid chromatography–mass spectrometry (LC-MS) has advantages over enzymatic methods given the large analyte concentration range. LC-MS has high accuracy, the ability to detect a broad range of concentrations, and minimal interferences.

Convenient Collection Process: Using a pre/post baseline challenge 4-hour collection- following literature guidelines to capture peak excretion times- instead of a pooled collection – eliminates the need for bulky urine collection containers and inconvenient collection experiences. There is also an easy to use vacuum pressure collection device that eliminates the need for messy pipette transferring and reduces contamination and bacterial growth by reducing sample exposure to air.

Simple Interpretation: Results are explained clearly through the Lactulose-Mannitol Ratio guideline that is well established in research and clinical communities.

Leaky Gut Tests


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