People with inflammatory bowel disease show increased leakage of a sugar molecule called 13C-mannitol through the small intestine during both active flare-ups and periods of remission, compared to...

Pro

Against

Mechanism

Synthesis from 1 study

How it works

Even when people with inflammatory bowel disease feel better, the tiny gaps between cells in their small intestine stay looser than normal, letting small sugars leak through into the blood and then into urine. Larger molecules don’t leak, which means it’s not a total breakdown — just a specific...

Most probable mechanism

In Simple Terms

The barrier between cells in the small intestine becomes looser, allowing small molecules like mannitol to slip through the gaps between cells and enter the bloodstream, which then shows up in urine — even when there’s no active inflammation.

Causal chain

Structural alterations in tight junction proteins reduce the integrity of the epithelial barrier in the small intestine

Supported by evidence

Evidence from Studies

Supporting (1)

Community contributions welcome

Intestinal Permeability In Vivo in Patients With Inflammatory Bowel Disease: Comparison of Active Disease and Remission.

Cross-Sectional Study

Human

2025 Sep 1

Contradicting (0)

Community contributions welcome

No contradicting evidence found

Gold Standard Evidence Needed

According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.

Source Study

Intestinal Permeability In Vivo in Patients With Inflammatory Bowel Disease: Comparison of Active Disease and Remission.

Score: 44

DOI: 10.1093/ibd/izaf043

Similar Assertions

In people with inflammatory bowel disease, the level of intestinal permeability measured by a specific urine test is similar whether their disease is active or in remission, suggesting that the barrier function of the gut remains altered regardless of symptom status.

91%

People with inflammatory bowel disease have a more permeable intestinal barrier than healthy people, even when they are not experiencing symptoms. This is measured by higher levels of two sugars, 13C-mannitol and lactulose, appearing in their urine after ingestion.

90%

Measuring the ratio of lactulose to mannitol in urine does not reliably detect changes in intestinal permeability in people with inflammatory bowel disease compared to healthy individuals or between disease states. However, the individual amounts of 13C-mannitol and lactulose excreted in urine are higher in people with inflammatory bowel disease.

84%

In people with inflammatory bowel diseases, the lining of the intestines becomes more porous, and this change is linked to several other long-term health conditions.

76%