RecruitingNAINTERVENTIONAL

Mapping the Impact of Gut Microbiota on Brain and Behavior Through the Lens of GABA

This research is investigating a fascinating connection between the tiny bugs living in our gut and our brain function, specifically focusing on a chemical called GABA. We know gut bacteria produce various substances, including brain chemicals, and some studies suggest this 'gut-brain' link plays a role in mental health. However, very little is known about how these gut-produced brain chemicals impact healthy people. This study aims to find out if a specific probiotic, which contains a type of bacteria known to make GABA, can actually change GABA levels in the brain and influence how we think and behave. We'll be comparing the effects of this probiotic to a dummy pill to understand its real impact.

At a glance

Status

Recruiting

Phase

Sponsor

University of Reading

Enrolment target

Start

21 May 2022

Estimated completion

31 Dec 2026

Healthy

What is this study about?

Imagine your gut as a bustling city, full of tiny residents – bacteria! These gut bacteria don't just help digest your food; they also produce various chemicals, some of which are very similar to the ones your brain uses to communicate. One of these important chemicals is called GABA, which plays a role in calming the brain and influencing things like mood and focus.

While animal studies have hinted at a strong link between these gut dwellers and how our brains work, we don't know much about how this all happens in healthy people. We've seen that people with certain health issues like anxiety or gut problems sometimes have different types of gut bacteria. This study wants to explore whether a special probiotic (a supplement containing good bacteria) can actually change the levels of GABA in your brain and affect how you perform on tasks that rely on GABA.

We're trying to answer two main questions: Can a probiotic that makes GABA in the lab actually boost GABA in your brain? And can this change in gut bacteria influence things like your behaviour and personality traits? By understanding this, we hope to learn more about the amazing connection between our gut and our brain.

Key takeaways

Exploring how gut bacteria influence brain health.
Investigating a specific probiotic and its effect on a brain chemical called GABA.
Participation involves taking a daily capsule and regular check-ups over 12 weeks.
Aims to understand the gut-brain connection in healthy individuals.
Your contribution helps advance scientific understanding.

Who may be eligible?

This study is looking for healthy men who are between 18 and 50 years old. You should be right-handed and have grown up in the UK or another European country. Your Body Mass Index (BMI), which is a measure of your weight compared to your height, should be between 18.5 and 30.

There are also some reasons why you might not be able to join. For example, if you've taken antibiotics or certain stomach medications (like PPIs) in the last three months, or if you smoke regularly. We also can't include you if you drink more than 14 units of alcohol a week, or if you're currently using certain medications for mental health or recreationally.

Finally, if you regularly take probiotics or prebiotics, or if you've been diagnosed with certain brain conditions, mental health conditions, or gut problems like inflammatory bowel disease (IBD) or irritable bowel syndrome (IBS), this study isn't suitable for you.

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 a man aged between 18 and 50?
Do you mostly use your right hand for tasks?
Have you grown up in the UK or another European country?
Is your weight generally considered healthy (BMI between 18.5 and 30)?
Have you avoided antibiotics in the last three months?
Do you currently not take probiotic supplements?

Answer every question to see your result.

What does participation involve?

If you decide to take part, the study will last for 12 weeks and involve five visits to the University of Reading. First, you'll have a screening visit to make sure you meet all the requirements. After that, there will be four more visits, at the start, week 4, week 8, and week 12.

During the study, you'll be asked to take a capsule every day – sometimes it will be the special probiotic, and other times it will be a plain dummy pill (a placebo). You won't know which one you're taking at any given time, and neither will the researchers. We'll ask you to take your capsule at least six out of seven days each week.

At your visits, we'll collect samples like poo, blood, and urine. You'll also take part in some fun tasks designed to measure your brain activity and how you behave. Finally, to help us understand your diet, we'll ask you to fill in an online food diary once every four weeks.

Potential risks and benefits

Taking part in research always has a balance of potential benefits and risks. You might not directly benefit from this study, but your contribution will help us learn more about the fascinating connection between our gut bacteria and our brain, which could lead to better understanding and treatments in the future. As with any study involving supplements, there's a small chance of mild side effects, but the probiotic used has been safely studied. You have the right to withdraw from the study at any time, for any reason, without it affecting your medical care.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

University of Reading
Verified postcode
Reading, United Kingdom· Recruiting

Common questions

What is a probiotic?

A probiotic is a supplement containing 'good' bacteria, like those naturally found in your gut, which can help keep your digestive system healthy.

What is GABA?

GABA is a natural chemical in your brain that helps to calm nerves and reduce stress. It plays a role in how you think and feel.

What does 'double-blind placebo-controlled' mean?

It means neither you nor the research team will know if you're taking the probiotic or a dummy pill (placebo). This helps make sure the results are fair.

Will I have to have a brain scan?

Yes, part of the study involves some brain measurements, which may include an MRI scan. We'll check carefully to make sure MRI is safe for you.

What will happen to my samples?

Your samples (blood, urine, poo) will be analysed to look for changes in gut bacteria and other chemicals, helping us understand the effects of the probiotic.

How to find out more

Bhismadev chakrabarti, PhD

b.chakrabarti@reading.ac.uk +44 118 378 5551 Official trial record

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