Clinical trial to evaluate the correlation between variation in intestinal lactase activity measured with LacTEST 0.45g and alteration of intestinal barrier integrity and/or intestinal permeability in patients with celiac disease

Coeliac disease is an autoimmune condition where eating gluten—a protein found in wheat, barley, and rye—causes the body to attack its own gut lining. Over time, this flattens the tiny finger-like projections (villi) in the small bowel that help absorb nutrients. One of the key enzymes found on healthy villi is lactase, which helps break down dairy sugars. When the gut is damaged, lactase levels drop, and the gut barrier can become leaky.

The only effective treatment for coeliac disease is a lifelong gluten-free diet. As the gut heals, the villi grow back, lactase levels recover, and the gut lining becomes stronger. At present, the main way doctors check if the gut has truly healed is by performing an endoscopy—passing a small camera down into the gut to take tiny tissue samples (biopsies). Because endoscopies can be uncomfortable, doctors are looking for gentler ways to track healing.

This trial investigates a testing product called LacTEST. It is a powdered drink that contains a sugar compound broken down specifically by the lactase enzyme. If your gut is healing and producing lactase, the sugar is processed and later filtered out into your urine. By checking urine samples over five hours after having the drink, doctors can see how much enzyme activity is present.

Over the course of a year, researchers will track participants to see if the LacTEST urine results match up with standard gut biopsies, blood antibody tests, and stool checks. If proven accurate, this test could provide a much easier way to monitor gut recovery and barrier strength in people with coeliac disease.