RecruitingNAINTERVENTIONAL

Tryptophan for Impaired AhR Signaling in Celiac Disease

This study is investigating if an amino acid supplement, L-tryptophan, can help people with coeliac disease who still have symptoms even after strictly following a gluten-free diet for over a year. Fifty adults, aged 18 to 75, whose symptoms are not getting better will receive either L-tryptophan or a dummy pill (placebo) for three weeks. Researchers will then check if the supplement has a positive effect on their symptoms and gut health. This trial is hoping to find new ways to help those living with coeliac disease whose symptoms persist despite their best efforts with diet.

At a glance

Status

Recruiting

Phase

Sponsor

McMaster University

Enrolment target

Start

01 Dec 2022

Estimated completion

01 Jun 2025

Tryptophan Metabolism Alterations Celiac Disease

What is this study about?

You might have coeliac disease and already follow a strict gluten-free diet. But what if you still feel unwell? This study is exploring a new idea to help people like you. It's looking at whether a supplement called L-tryptophan, which is a building block for proteins found in certain foods, can help improve your symptoms if they haven't gotten better on a gluten-free diet.

Researchers think that for some people with coeliac disease, an important natural process in the body, which involves tryptophan, might not be working as it should. This could be leading to ongoing gut problems and other symptoms. By giving L-tryptophan as a supplement, they hope to get this process working better and ease your discomfort.

This is a 'randomised, double-blind, placebo-controlled' study. This means that participants will be randomly chosen to receive either the L-tryptophan supplement or a 'dummy' pill (called a placebo). Neither you nor your doctor will know which one you're taking, which helps to make the results as fair and accurate as possible. The aim is to see if L-tryptophan really makes a difference compared to not taking it.

Key takeaways

Targets persistent coeliac symptoms despite a gluten-free diet.
Investigates L-tryptophan supplement for three weeks.
Compares L-tryptophan to a dummy pill (placebo).
Requires following a specific low-tryptophan, gluten-free diet.
Involves clinic visits, blood/stool/urine samples, and an endoscopy.

Who may be eligible?

To join this study, you need to be an adult between 18 and 75 years old. You must have a confirmed diagnosis of coeliac disease, meaning it was shown through a biopsy and blood tests. Crucially, you need to have been on a gluten-free diet for at least a year, but still be experiencing significant coeliac-related symptoms.

There are also some reasons why you might not be able to join. For example, if you're taking certain medications like strong antacids or antibiotics, or if you've recently had bariatric surgery. If you have other serious health conditions like inflammatory bowel disease, severe diabetes, or certain allergies, you also wouldn't be able to take part. This is to ensure the study is safe for everyone involved and that the results are clear.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you between 18 and 75 years old?
Do you have a confirmed coeliac disease diagnosis?
Have you been strictly gluten-free for over a year?
Do you still have significant coeliac symptoms despite your diet?
Are you free from certain other long-term health conditions?
Are you not currently taking specific medications like strong antacids or antibiotics?

Answer every question to see your result.

What does participation involve?

If you decide to take part, the study will last for a total of three weeks. During this time, you'll be given either the L-tryptophan supplement or a dummy pill to take. You'll have three visits to the clinic.

At your first visit, you'll learn all about the study and be given your tablets for the entire three weeks. You'll also meet with a dietitian who will help you with a special low-tryptophan, gluten-free diet while you're in the study. You'll need to follow this diet carefully. At your second and third visits, which happen just before and after you take the supplements, you'll be asked to fill out questionnaires about your diet and symptoms. You'll also provide blood, stool (poo), and urine samples. Additionally, you will have an endoscopy, which involves a small camera being passed down your throat to take tiny tissue samples (biopsies) from your gut. This helps us see what's happening inside. We'll also ask you to keep a record of what you eat for a few days to check how well you're following the diet.

Potential risks and benefits

Potential benefits of taking part could include an improvement in your coeliac disease symptoms. While we hope for positive results, there's no guarantee that you will personally benefit from the L-tryptophan supplement. As with any study, there could be some risks, such as side effects from the supplement or discomfort from the procedures like blood tests or the endoscopy. All procedures will be carried out by experienced medical professionals. You are free to withdraw from the study at any time, for any reason, without it affecting your medical care.

Locations (1)

McMaster University
Verified postcode
Hamilton, Canada· Recruiting

Common questions

What is L-tryptophan?

L-tryptophan is a natural substance your body uses to make proteins and other important chemicals. It's found in many foods like turkey, chicken, and milk.

What is a placebo?

A placebo is a 'dummy' pill that looks just like the real supplement but contains no active ingredient. It helps us see if the supplement truly makes a difference.

Will I have to change my diet?

Yes, you will follow a special low-tryptophan, gluten-free diet during the study, advised by a dietitian. This is to make sure we can clearly measure the supplement's effects.

How long does the study last?

The study itself lasts for three weeks, involving three clinic visits during that time.

Will I know if I received the real supplement or the placebo?

No, neither you nor the study team will know which you received until after the study has finished, to avoid influencing the results.

How to find out more

Gaston H Rueda, MD

ruedag@mcmaster.ca 905 521-2100 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.