RecruitingNAINTERVENTIONAL

CALM Study: Can A Prebiotic Fibre bLend Improve Stress, Mood, and Anxiety?

The CALM Study is investigating whether a specific powdered fibre supplement, known as a prebiotic blend, can help reduce stress in healthy adults experiencing mild to severe stress. There's growing interest in how our gut health might affect our brain and feelings, often called the 'gut-brain axis'. This study aims to see if this prebiotic fibre can make a difference to perceived stress. Researchers will also look at how this supplement might impact other areas of health, including mood, anxiety, how we think, inflammation in the body, and the balance of bacteria in our gut. Participants will either receive the prebiotic fibre blend or a non-active powder to compare the effects.

At a glance

Status

Recruiting

Phase

Sponsor

Myota GmbH

Enrolment target

156

Start

02 Oct 2025

Estimated completion

30 Dec 2026

Stress

What is this study about?

The CALM Study is all about understanding the connection between our gut and our brain, especially when it comes to stress. You might have heard people talk about the 'gut-brain axis' – it's the idea that what's happening in your digestive system can really affect your mood and how you feel. We know that stress can have a big impact on our bodies, even if we're otherwise healthy. This study wants to find out if a special type of fibre, called a prebiotic, can help reduce those stress levels.

Prebiotic fibres are like food for the good bacteria in your gut. By feeding these good bacteria, we hope to see positive changes in how people manage stress. The study will give some participants a powdered prebiotic fibre blend and others a simple, inactive powder (like a sugar substitute) so we can fairly compare the results. Neither you nor the study team will know who is getting which powder until the study is over.

Beyond simply looking at stress, we'll also be exploring whether this fibre supplement can improve other important aspects of health. This includes how you feel emotionally (your mood), your levels of anxiety, how well your brain works (your thinking and memory), signs of inflammation in your body, and the overall balance of bacteria living in your gut. By looking at all these things together, we hope to get a much clearer picture of how gut health might support our overall mental well-being.

Key takeaways

The study explores if a special fibre can help with stress.
It investigates the 'gut-brain axis' and its link to mood and anxiety.
Participants will take a daily powdered supplement (fibre or inactive).
It aims to improve understanding of gut health's role in mental well-being.
Your involvement could help future treatments for stress.
You won't know if you're getting the active supplement or an inactive one.

Who may be eligible?

To join the study, you need to be a healthy adult between 18 and 50 years old and able to understand and agree to take part. You should also be able to follow the study instructions and attend any necessary appointments. Importantly, you need to be experiencing mild to severe stress, which will be checked using a special questionnaire.

There are some reasons why you might not be able to join. For example, if you smoke, have certain food allergies, or have conditions like diabetes, heart disease, or certain mental health conditions (like a recent diagnosis of depression), you wouldn't be able to participate. Also, if you're taking specific medications, such as those for cholesterol, blood pressure, depression, anxiety, or hormonal birth control, you would be excluded.

Other reasons include being pregnant, breastfeeding, or planning to become pregnant, having used certain antibiotics or weight-loss drugs recently, or having changed your diet a lot lately. If you already take daily prebiotic or probiotic supplements, or have certain stomach or bowel conditions, kidney disease, or cancer treatment in the last three years, you also wouldn't be eligible. This helps ensure the study only includes people where the fibre supplement's effects can be clearly measured without other influences.

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 50 years old?
Do you feel stressed (mild to severe levels)?
Are you generally healthy and don't smoke?
Are you not currently pregnant or breastfeeding?
Are you not taking certain medications (like antidepressants, anxiety meds, or hormonal birth control)?
Do you not have conditions like diabetes, heart disease, or certain stomach problems?

Answer every question to see your result.

What does participation involve?

If you join the CALM Study, you'll be asked to take a powdered supplement every day for a set period. This will either be the special prebiotic fibre blend or a non-active powder. You won't know which one you're taking, and neither will the study team, to make sure the results are fair.

You'll need to attend some appointments, where researchers will check your stress levels, ask about your mood and how you feel, and possibly take some samples, like blood or stool, to look at inflammation and your gut bacteria. You might also fill out questionnaires about your diet and general health. The study will likely involve a few check-ups over a number of weeks or months, and the total duration of your involvement will be explained in full before you agree to take part.

Potential risks and benefits

Taking part in this study may offer potential benefits, such as contributing valuable knowledge to science about how gut health affects stress and overall well-being. If you receive the active prebiotic blend, you might experience an improvement in your stress levels, mood, or anxiety. However, there's also a chance you might experience no benefit, especially if you receive the inactive powder. Potential risks are generally low with prebiotic supplements but could include mild digestive discomfort, such as bloating or gas. You will be closely monitored by the study team, and 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.

CALM Study Site
Verified postcode
London, United Kingdom· Recruiting

Common questions

What is a 'prebiotic fibre blend'?

It's a special mixture of fibres that acts as food for the good bacteria in your gut, helping them grow and thrive.

What does 'gut-brain axis' mean?

It's the natural communication system between your digestive system and your brain, showing how they can influence each other.

Will I know if I'm getting the active supplement?

No, you won't. This is called 'blinding' and helps make sure the study results are as accurate and unbiased as possible.

How long will I need to be in the study?

The exact duration will be explained to you, but studies like this usually run for several weeks or a few months.

What happens if I feel unwell during the study?

You should always tell the study team immediately if you experience any side effects or feel unwell while taking part.

How to find out more

Caitlin Hall, PhD, RD

caitlin@myotahealth.com 07830709854 Official trial record

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