Active not recruitingNAINTERVENTIONAL

Prebiotic Effects on Anxiety, Cortisol, and Emotional Processing in Mild-to-Moderately Stressed Adults

Living with stress can be tough, impacting our health and how we feel. This study is exploring whether a type of fibre called a prebiotic, which helps good gut bacteria grow, could reduce feelings of stress. Researchers are inviting adults aged 25-40 who experience mild to moderate stress to take part. Participants will take either a prebiotic supplement (Bimuno®) or a dummy supplement (placebo) for six weeks. They'll also complete questionnaires and simple tests at the University of Reading, and collect saliva samples to check stress hormone levels. The aim is to see if prebiotics can be a helpful way to support people dealing with everyday stress.

At a glance

Status

Active not recruiting

Phase

Sponsor

University of Reading

Enrolment target

Start

31 Mar 2025

Estimated completion

01 Feb 2026

Mild-to-Moderate Stress

What is this study about?

Many of us face stress in our daily lives because of things like work, money, or family. When stress goes on for a long time, it can make us feel unwell both mentally and physically. Scientists are always looking for new ways to help people manage stress.

This study looks at something called 'prebiotics'. Prebiotics are special plant fibres that you can find in certain foods or supplements. They act like food for the good bacteria in your gut. When these good bacteria thrive, they produce helpful substances that research suggests might be linked to feeling less stressed. The researchers want to find out if taking a prebiotic supplement can actually help people who are feeling mild to moderate stress.

The main goal of this research is to see if a specific prebiotic supplement, called Bimuno®, can improve how stressed people feel, boost their overall mental well-being, and even help them sleep better. They will also collect saliva samples to measure 'cortisol', which is a hormone your body releases when you're stressed. By comparing people who take the prebiotic to those who take a dummy supplement (a placebo), the team hopes to understand if prebiotics could be a simple, helpful way to support people in managing their stress.

Key takeaways

This study explores if a prebiotic supplement can help reduce stress.
It targets adults aged 25-40 experiencing mild to moderate stress.
Participants take a supplement (prebiotic or placebo) for six weeks.
The study involves visits to the University of Reading for tests and questionnaires.
Saliva samples will be collected to check stress hormone levels.
Participation could help future understanding of stress management.

Who may be eligible?

This study is looking for volunteers who are between 25 and 40 years old. You should feel like you are experiencing at least mild stress in your daily life. The researchers will ask you some questions to make sure your stress levels fit what they are looking for.

There are also some things that would mean you can't take part. For example, if you've recently taken antibiotics or regularly use other gut-health supplements. You also can't participate if you've been diagnosed with a mental health condition, or used antidepressant medication in the last six months.

Also, if you smoke, follow a vegan diet, have certain allergies like dairy or lactose intolerance, or work unusual shifts, you wouldn't be able to join. People with certain health conditions like diabetes, heart problems, stomach issues (like IBS), or chronic fatigue would also not be eligible. This is to make sure the study results are clear and not affected by other health factors.

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 25 and 40 years old?
Do you feel you experience mild to moderate stress?
Have you avoided antibiotics in the last three months?
Do you avoid regular use of prebiotics, probiotics, or similar supplements?
Have you not been diagnosed with a mental health condition in the past six months?
Do you not smoke and are not on a vegan diet?

Answer every question to see your result.

What does participation involve?

If you decide to take part, you'll first read some information and sign a consent form, then answer some health and lifestyle questions online to see if you're suitable. If you are, you'll come to the University of Reading for a short 'practice' visit. Here, you'll get used to the questionnaires and tests you'll complete later, and learn how to collect saliva samples at home.

After that, you'll have two main study visits at the University, about six weeks apart. In between these visits, you'll need to remember to take either the prebiotic supplement or a dummy pill once a day at home for six weeks. You'll also be asked to collect saliva samples on four different days during this time. For these main visits, you'll be asked to eat a specific light breakfast before coming in. The whole study will involve these visits and taking the daily supplement for about six weeks in total.

Potential risks and benefits

Taking part in any study has potential benefits and risks. You might not directly benefit from this study, but your contribution could help scientists learn more about how prebiotics affect stress, which might help others in the future. As with any supplement, there's always a small chance of mild side effects, though prebiotics are generally considered safe. You will be monitored throughout the study. Remember, your participation is completely voluntary, and you can 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.

Nutrition, Cognition & Health Lab, School of Psychology and Clinical Language Sciences, University of Reading
Verified postcode
Reading, United Kingdom

Common questions

What is a 'prebiotic'?

A prebiotic is a special fibre that acts like food for the good bacteria in your gut, helping them grow and thrive.

What is 'mild-to-moderate stress'?

This refers to stress levels that are noticeable and impactful, but not severe enough to be a diagnosed mental health condition. The study will assess this to make sure you fit.

Will I know if I'm taking the real prebiotic or the dummy pill?

No, this is a 'blinded' study, meaning neither you nor the researchers will know who is getting the active prebiotic and who is getting the placebo until the study is over. This helps keep the results fair.

What does collecting saliva samples involve?

You'll be given kits and shown how to collect a small amount of your saliva at specific times at home. It's a simple, non-painful process.

How long will the study last?

Your active involvement, including taking the supplement and attending visits, will last for about six weeks.