** NOTE: All laboratory testing requires an authorizing physician. DHA Laboratory offers a patient direct program that partners you with an authorizing physician. If you have any additional questions regarding the availability of testing, please contact our laboratory by telephone or email. **
This test measures the ability of two sugar molecules, lactulose and mannitol, to permeate the intestinal epithelial barrier. Ordinarily, mannitol is efficiently absorbed but lactulose, a larger molecule, is not. This test can help to identify malabsorption and “leaky gut” syndrome (abnormal intestinal permeability), which is often associated with inflammation specifically in the gastrointestinal tract. This test requires a baseline urine collection followed by a six-hour timed urine collection after ingesting a lactulose and mannitol solution.