Recruiting

Tryptophan

Sponsor:

McMaster University

Code:

NCT05576038

Conditions

Tryptophan Metabolism Alterations

Celiac Disease

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Interventions

L-Tryptophan

Freedom SimpleCap Powder

Study Details

Brief summary:

This is a prospective, randomized, double-blind, placebo-controlled exploratory trial to evaluate the effect of L-tryptophan supplementation on celiac-related symptoms in individuals who have biopsy-confirmed celiac disease (CeD) and symptoms non-responsive to a gluten-free diet (GFD). Fifty participants, aged 18 to 75 years, who self-report persistent CeD-related symptoms despite taking a GFD for more than 1 year and who score > 40 on the Celiac Symptom Index (CSI) will be randomized to receive L-tryptophan or placebo for 3 weeks.

Conditions

Tryptophan Metabolism Alterations

Celiac Disease

Study ID

NCT05576038

Start date

Dec 1, 2022

Status verified date

Jan, 2025

Completion date

Jun 1, 2025

Anticipated

Primary completion date

Apr 1, 2025

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Inclusion criteria:

  • 18 and 75 years of age
  • Celiac disease (CeD) diagnosis: Individuals with histological and serological evidence of CeD serology (positive biopsy and anti-tTG IgA)
  • Persistent CeD related symptoms (>40 on the Celiac Symptom Index) despite >1 year of a gluten free diet (GFD)

Exclusion criteria:

  • Acid anti-secretory and antacid medications
  • Antibiotics, antibacterial agents or probiotics, currently, or within the last 8 weeks
  • Current organic gastrointestinal or other autoimmune diseases, such as inflammatory bowel disease or diabetes mellitus (type 1)
  • Lactose and/or fructose intolerance
  • History of bariatric surgery, fundoplication or gastrectomy (partial or complete)
  • Connective tissue disease
  • Concurrent organic GI pathology other than benign polyps, haemorrhoids, lipomas, Helicobacter pylori infection, diverticulosis and melanosis coli
  • Chronic treatment with high dose opioids
  • Alcohol or drug abuse
  • Concurrent systemic disease and/or laboratory abnormalities considered by investigators to be a risk or that could interfere with data collection
  • Allergy or sensitivity to any component of the study medication or placebo
  • Use of lithium and monoamine oxidase inhibitors (MAOIs)
  • Participation in another dietary treatment study within the last 4 weeks

Study Design

Enrollment

50 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

active comparator: L-Tryptophan

L-tryptophan\* supplements (Tryptan, Valeant Canada LP): each treatment capsule contains 500 mg of L-Tryptophan; talc and magnesium stearate.

Study participants will be instructed to take 2 x 500 mg capsules (1000 mg) every 8 hrs, three times a day. (total daily dose: 3000 mg) for a total of 3 weeks.

Instructions will be printed on the label of the pill container.

placebo comparator: Freedom SimpleCap Powder

500 mg of SimpleCap Powder. Study participants will be instructed to take 2 x 500 mg capsules (1000 mg) every 8 hrs, three times a day. (total daily dose: 3000 mg) for a total of 3 weeks.

Instructions will be printed on the label of the pill container.

Interventions

L-Tryptophan

L-tryptophan is an essential amino acid responsible for activating the aryl hydrocarbon receptor (AhR). Dietary tryptophan is metabolized by the gut microbiota producing several 'indoles' such as (indole-3-aldehyde (IAld), indole-3-acetic acid (IAA), indole-3 propionic acid (IPA), indole-3-acetaldehyde (IAAld), indole-3-lactic acid (ILA) and indole-acrylic acid) and tryptamine, which are ligands for the AhR, a nuclear transcription factor involved in activating target genes responsible for maintaining gut integrity. Prior literature suggests that patients with active celiac disease have a lower functional capacity to produce these AhR ligands, which further impairs the AhR pathway. Hence, the aim of this study is to assess the effects of tryptophan supplementation in patients with celiac disease, non-responsive to a GFD for more than 1 year compared with the effects of an inactive, placebo comparator, L-leucine.

Freedom SimpleCap Powder

Freedom SimpleCap Powder is a high functionality capsule and tablet excipient composite comprised of filler, glidant, disintegrant and lubricant (ingredients include: Microcrystalline Cellulose, Silicon Dioxide Colloidal, Sodium Starch Glycolate, Sodium Stearyl Fumarate). This capsule is dye, lactose and gluten free and will not interfere with the AhR pathway. Freedom SimpleCap Powder makes oral capsule formulation convenient, quick and simple Thus, this SimpleCap Powder will be an appropriate placebo comparator for this study.

Primary outcome measure

  • Measurement of Celiac Symptom Index (CSI) [ Time Frame: 3 weeks ]

Central Contacts and Locations

Central contacts

Gaston H Rueda, MD

905 521-2100ruedag@mcmaster.ca

Utkarshini N Kirtikar, MSc

905 521-2100kirtikau@mcmaster.ca

Locations

McMaster University

Recruiting

Hamilton, Ontario, Canada, L8N3Z5

More Information

Sponsor

McMaster University

Last update posted

Jan 10, 2025

Last verified

Jan, 2025

Keywords

  • Tryptophan
  • Celiac disease
  • Aryl Hydrocarbon Receptor

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by McMaster University on 2025-01-10.