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‘Leaky Gut’ Might Be an Early Warning Sign of Crohn’s Disease, New Research Shows

Crohn's Disease Leaky Gut

No one knows exactly what causes Crohn’s disease, a chronic, inflammatory condition in which the body’s immune system mistakenly attacks the digestive tract, causing such symptoms as diarrhea and abdominal pain. But experts do know that diagnosing Crohn’s as soon as possible offers the best chance of preventing the disease from worsening and avoiding serious complications.

New research suggests that a test used to measure intestinal permeability — often referred to as a “leaky gut” — might help identify Crohn’s disease earlier.

When everything in the gastrointestinal tract is working properly, food that travels through your GI tract largely stays there, though tiny holes allows nutrients to pass through the gut wall and into your bloodstream. If those holes are too large, however, bacteria and other substances that shouldn’t cross the boundary of the gut wall end up reaching the bloodstream. This is thought to contribute to inflammation.

People who have a leaky gut sometimes report experience digestive distress, headaches, rashes, or other symptoms, but many Western medical professionals do not consider “leaky gut syndrome” to be a valid diagnosis or consider it dangerous.

Now, new research published in the journal Gastroenterology might lead them to think differently. In the study, researchers measured intestinal permeability in 1,420 healthy first-degree relatives of Crohn’s disease patients between 2008 and 2015. People with a close relative of someone with Crohn’s have a higher than average risk of developing it themselves.

Intestinal permeability was assessed by having study participants drink a solution containing two types of sugars, lactulose and mannitol, then measuring quantities of both in their urine. In people with a healthy gut, these sugars mainly stay in the intestines and aren’t excreted in urine.

Within three years, 50 study participants were diagnosed with Crohn’s disease. The researchers determined that members of this group were significantly more likely to have had abnormal intestinal permeability during the earlier phase of the study than people who were not diagnosed with Crohn’s disease.

“Abnormal gut barrier function might serve as a biomarker for risk of [Crohn’s disease] onset,” the researchers wrote.

Future studies will be needed to confirm these findings.

Denno MD, et al. Use of the Lactulose to Mannitol Ratio to Evaluate Childhood Environmental Enteric Dysfunction: A Systematic Review. Clinical Infectious Diseases. November 2014. doi:

Turpin W, et al. Increased Intestinal Permeability is Associated With Later Development of Crohn’s Disease.Gastroenterology. August 10, 2020. doi:

Swift D. Study ID’s Possible Crohn’s Disease Prodrome. MedPage Today. August 11, 2020.