Side by side

1. 1.Acts on the protein zonulin, which opens the tight junctions between intestinal lining cells.
2. 2.By opposing zonulin, it keeps those junctions closed and reduces paracellular permeability — the gaps through which larger fragments cross the gut wall.
3. 3.In coeliac disease, gluten fragments crossing that barrier trigger the immune reaction that damages the intestine.
4. 4.The peptide works upstream of the immune response; it does not suppress the immune system or repair existing damage.

• Coeliac disease in people already on a gluten-free diet
• Persistent symptoms despite a gluten-free diet
• Intestinal permeability in healthy volunteers
• Irritable bowel syndrome (early-stage only)

• Reduced intestinal permeability markers in early studies
• Some improvement in gastrointestinal symptom scores in a phase 2b trial
• Phase 3 trial did not meet its primary endpoint, which ended the development programme
• No meaningful change in intestinal villous architecture

• Adverse events were similar to placebo in the published trials
• Mild gastrointestinal symptoms
• Headache
• Long-term safety was never established because development stopped

Research context only — there is no approved product. Trials used oral capsules of 0.125–1 mg taken three times daily before meals for 12–52 weeks. It was always investigated as an add-on to a gluten-free diet, never as a replacement.

Research context only