Larazotide for Intestinal Permeability & Gut Barrier Repair — Gut
Zonulin antagonist peptide that tightens intestinal tight junctions to reduce gut permeability and gluten-related symptoms.
Overview
Larazotide acetate (AT-1001, INN-202) is a synthetic octapeptide derived from Vibrio cholerae zonula occludens toxin that acts as a zonulin receptor antagonist, tightening intestinal tight junctions and reducing paracellular permeability. Developed by Alba Therapeutics and later Innovate Biopharmaceuticals (now 9 Meters Biopharma), larazotide has completed multiple Phase 2 and Phase 3 clinical trials for celiac disease. The Phase 2b trial (Leffler et al., Gastroenterology 2015, PMID: 26004136, n=342) demonstrated significant reduction in celiac symptoms at 0.5mg TID vs placebo during gluten challenge. A Phase 3 trial (CeliAction, n=525) showed trends in symptom improvement but did not meet the primary endpoint using a novel PRO instrument. However, post-hoc analyses and earlier trials consistently showed efficacy in reducing intestinal permeability and symptom scores. Larazotide is the first-in-class tight junction regulator to reach Phase 3 for celiac disease. It works locally in the gut lumen with minimal systemic absorption (<1%), providing an excellent safety profile. Being investigated for non-celiac gluten sensitivity and general intestinal hyperpermeability.
Indications
- Celiac disease symptom management (adjunct to gluten-free diet)
- Intestinal hyperpermeability (leaky gut syndrome)
- Non-celiac gluten sensitivity (investigational)
- Tight junction dysfunction and gut barrier repair
Mechanism of Action
Zonulin release (triggered by gliadin/gluten) opens paracellular tight junctions, increasing intestinal permeability
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Larazotide Acetate | 0.5 mg | Three times daily (15 min before meals) | Dose showing best efficacy in Phase 2b (PMID: 26004136); take before each meal |
| Larazotide Acetate | 1 mg | Three times daily (15 min before meals) | Higher dose tested in Phase 2; 0.5mg showed better results than 1mg or 2mg |
Evidence Grade
GRADE B
Safety & Contraindications
- Minimal systemic absorption (<1%) - acts locally in the gut lumen
- Well-tolerated across all clinical trials; adverse event profile similar to placebo
- NOT FDA-approved; Phase 3 trials completed but primary endpoint not met
- Does NOT replace gluten-free diet in celiac disease - adjunctive therapy only
- Most common side effects: headache, abdominal pain, nausea (similar to placebo rates)
- Not a substitute for celiac disease diagnosis or standard management