Larazotide Acetate
Larazotide acetate (AT-1001) is a synthetic 8-amino-acid peptide that regulates tight junction proteins in the intestinal epithelium. It is the leading research compound for intestinal permeability ('leaky gut'), with completed Phase 2 clinical trials in celiac disease and active investigation in other gut-barrier conditions.
Common Dosage
0.5mg - 2mg oral (research phase dosing)
Category
Recovery
- Tight junction restoration
- Intestinal permeability reduction
- Celiac disease symptom management
- Reduced gut inflammation
- Gut microbiome barrier support
Larazotide acetate (originally designated AT-1001) was developed by Alba Therapeutics based on foundational research by Dr. Alessio Fasano at the University of Maryland. Fasano's lab identified zonulin — an endogenous protein that regulates intestinal tight junction permeability — and discovered that gliadin (a component of gluten) triggers zonulin release, opening tight junctions and increasing intestinal permeability. Larazotide was engineered as a tight junction regulator that competes with zonulin and prevents excessive permeability. It entered clinical development for celiac disease — one of the first drugs designed specifically to target intestinal permeability as a mechanism — and completed Phase 2b trials that demonstrated statistically significant reductions in celiac symptoms compared to placebo.
Larazotide acetate works locally in the gastrointestinal tract by regulating occludin and zonula occludens proteins in intestinal epithelial tight junctions. It acts as a tight junction regulator — preventing the opening of paracellular spaces that would normally allow luminal antigens (gluten peptides, lipopolysaccharides, pathogens) to cross the epithelial barrier and trigger immune activation. Unlike immunosuppressants that blunt downstream inflammation, larazotide acts at the barrier level to prevent the initiating event. It is minimally absorbed systemically, meaning its primary action is confined to the intestinal lumen. It also inhibits gliadin-induced zonulin release and myosin light chain kinase (MLCK) activation — a key enzyme in tight junction contraction.
- Celiac disease — reducing GI symptoms and intestinal inflammation triggered by inadvertent gluten exposure
- Non-celiac gluten sensitivity — barrier restoration in symptomatic patients without autoimmune markers
- Inflammatory bowel disease — Crohn's disease and ulcerative colitis barrier permeability reduction
- Leaky gut syndrome — general intestinal permeability restoration across multiple etiologies
- Type 1 diabetes prevention research — zonulin-intestinal permeability-autoimmunity connection
- SIBO (Small Intestinal Bacterial Overgrowth) — barrier maintenance post-eradication
- Non-alcoholic fatty liver disease — gut-liver axis permeability reduction
Phase 2b Celiac Trial (CeDeX Study)
The CeDeX Phase 2b trial enrolled 342 symptomatic celiac patients on a gluten-free diet. The 0.5mg three-times-daily dose of larazotide achieved the primary endpoint of reducing celiac disease patient reported outcomes (CeD PRO) scores compared to placebo. The drug was well-tolerated with a safety profile similar to placebo, making it a leading candidate for celiac disease management of breakthrough symptoms.
Intestinal Permeability Biomarkers
Multiple studies measured lactulose:mannitol ratio (a direct intestinal permeability test) in larazotide-treated patients and found significant reductions compared to placebo in both celiac and non-celiac populations. Normalization of serum zonulin levels was also observed, validating the mechanistic target.
Autoimmunity Prevention Research
Based on Fasano's 'three-hit hypothesis' (genetic susceptibility + triggering factor + intestinal permeability), researchers have explored whether larazotide can interrupt autoimmune progression in type 1 diabetes. Animal model data shows delay in diabetes onset in NOD mice when larazotide is administered early — a finding with significant implications for human prevention trials.
- Not yet FDA-approved despite promising Phase 2b data — Phase 3 trial completion and regulatory filing pending
- Research primarily in celiac disease — extrapolation to other conditions is mechanistically supported but not clinically validated
- Oral bioavailability is minimal by design — it is not a systemic drug and should not be expected to have systemic effects
- Long-term safety data beyond 12-week trial periods is limited
- Some study participants reported headache as the most common adverse event above placebo rates
- Well-tolerated in clinical trials
- Mild GI discomfort in some subjects
- Headache (low frequency)