RecruitingNAINTERVENTIONAL

The Role of METhanogens in the PROgression Of Parkinson's Disease and Related Neurological Conditions

This study aims to understand the link between gut health and conditions like Parkinson's disease, dementia, and mild cognitive impairment. We know that gut problems like constipation are common in these conditions and might even speed up their progression, but the exact reasons are unclear. Methane gas, produced by gut microbes, can be measured with a simple breath test and has been linked to constipation and movement issues in Parkinson's. This research will compare methane levels in different groups: people with Parkinson's, those at high risk (with REM sleep behaviour disorder), people with memory problems, and healthy individuals. We'll follow participants over time to see how methane levels relate to gut function and symptoms. A smaller part of the study will also test if a probiotic can reduce methane in people with Parkinson's who have high levels.

At a glance

Status

Recruiting

Phase

Sponsor

University of Cambridge

Enrolment target

215

Start

01 Nov 2025

Estimated completion

01 Mar 2028

What is this study about?

This study is exploring an interesting connection between your gut health and brain conditions like Parkinson's disease and memory issues (like dementia or mild cognitive impairment). Many people with these conditions also experience gut problems, especially constipation. We’ve noticed that constipation might be linked to a faster progression of both Parkinson’s and Alzheimer’s disease, but we don't fully understand why these two parts of the body are so connected.

Our bodies naturally produce methane gas in the gut, made by tiny organisms. We can measure these methane levels with a simple breath test. We've seen that people with Parkinson's disease often have higher methane levels than healthy people, and this can be linked to constipation and even worse movement problems. However, we know less about how methane levels relate to memory and thinking problems. This research wants to get a clearer picture of these gut changes and how they might influence conditions affecting movement and memory.

To do this, we have two main parts to the study. The first part will observe 200 people over 18 months. We'll look at 50 people with Parkinson's, 50 people at high risk of Parkinson's (due to a sleep condition called REM sleep behaviour disorder), 50 people with memory problems, and 50 healthy individuals. We'll compare their methane levels, check blood and stool samples, and see how their gut works and how their symptoms change over time. The second, smaller part of the study will involve 15 people with Parkinson's who have high methane levels. We will give them a probiotic supplement (Lactobacillus reuteri) to see if it can help reduce the amount of methane they produce.

Key takeaways

This study explores how gut health, particularly methane gas, relates to Parkinson's and memory conditions.
It aims to understand if gut issues might affect how these conditions develop and progress.
The study involves comparing methane levels in people with Parkinson's, those at risk, people with memory problems, and healthy individuals.
A smaller part of the study will test if a probiotic can reduce methane in people with Parkinson's.
Your participation could help improve future understanding and care for these conditions.

Who may be eligible?

To join this study, you need to be 55 years old or older. We are looking for people in a few different groups: those with Parkinson's disease (diagnosed by specific criteria), those who have a sleep condition called REM sleep behaviour disorder (which can increase the risk of Parkinson's), and people with memory problems such as dementia or mild cognitive impairment. We also need healthy volunteers to compare results.

There are some reasons why you might not be able to join. For example, if you have other serious brain conditions, long-term inflammatory or autoimmune diseases, active cancer, diabetes, or an active infection. You also can't be taking certain medications like immunosuppressants, steroids (within the last few months), or regularly taking anti-inflammatory drugs or high-dose aspirin. We also can't include you if you've been in another trial recently, regularly use laxatives or certain supplements, or if you currently smoke. You must also be able to understand and speak English fluently.

If you are interested in the second part of the study, which involves taking a probiotic, you'd also need to make sure you're not allergic to any of its ingredients, such as isomalt, xylitol, L. reuteri DSM 17938, strawberry flavouring, or citric acid.

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 55 years old or older?
Do you have Parkinson's disease, REM sleep behaviour disorder, or a memory problem like dementia or mild cognitive impairment? (Or are you a healthy volunteer?)
Do you have any other serious health conditions like diabetes, cancer, or inflammatory diseases?
Are you currently smoking?
Have you used laxatives, certain supplements, or specific medications (like steroids or immunosuppressants) in the last few months?
Can you understand and speak English well?

Answer every question to see your result.

What does participation involve?

If you take part in the main observation study (Component 1), you would need to visit the study team twice over 18 months. During these visits, we would ask you questions about your health, perform some simple assessments, and collect breath, blood, and stool samples. You wouldn't be given any medication as part of this observation study.

If you are invited to take part in the smaller probiotic study (Component 2), you would also have specific visits. During this part, you would be given a probiotic supplement to take for a set period. We would then check to see if it changes your methane levels and how you feel. The total time you'd be involved would depend on which part of the study you join, but for the main study, it's 18 months of follow-up after your first visit.

Potential risks and benefits

There are no direct personal benefits from taking part in this study. However, your involvement will greatly help us understand the links between gut health and brain conditions, which could lead to better ways to help people in the future. The risks of taking part are generally low, mainly related to the minor discomfort of blood tests or collecting samples. If you take the probiotic, there's a small chance of mild side effects, but it's generally considered safe. Remember, you can choose to withdraw from the study at any time, for any reason, without it affecting your usual medical care.

Locations (1)

John Van Geest Centre for Brain Repair - Forvie Site, Robinson Way
Verified postcode
Cambridge, United Kingdom· Recruiting

Common questions

What is 'methane' in this study?

Methane is a gas produced by tiny living things (microbes) in your gut. We can measure it with a simple breath test.

What is a 'probiotic'?

A probiotic is a type of 'good' bacteria or yeast that you can take as a supplement, like those found in some yoghurts, that might help your gut health.

Why is 'REM Sleep Behaviour Disorder' mentioned?

This sleep condition is important because people with it have a higher chance of developing Parkinson's disease later on, so we're studying them as a 'high-risk' group.

Will I have to take any new medicines?

Only if you join the second, smaller part of the study where we are testing a probiotic supplement. The main study involves observations only.

How long will I be involved if I join?

If you join the main observation study, you'll be followed for 18 months with two visits. The probiotic study would involve a shorter period of taking the supplement and follow-up.

How to find out more

Marta Camacho, Dr.

msc72@cam.ac.uk +4401223334121 Official trial record

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