RecruitingNAINTERVENTIONAL

Effect of a Food Intervention With a Prebiotic Alone or Combined With B-vitamins on Gut Microbiota Diversity, Inflammation and Mental Health Outcomes in Older Adults (GutFood)

Researchers are investigating whether a special fruit drink, containing a fibre called inulin (a 'prebiotic') and/or B-vitamins, can improve gut health, reduce inflammation, and boost mental well-being in adults aged 50 and older. As people get older, their gut bacteria can change, and they might not get enough fibre or B-vitamins, which can affect their mood and general health. This study aims to see if adding these ingredients to a drink can make a positive difference. Participants will try one of three drinks (the fibre, the fibre with B-vitamins, or a plain placebo drink) for 12 weeks to see how their bodies respond.

At a glance

Status

Recruiting

Phase

Sponsor

University of Ulster

Enrolment target

Start

18 May 2026

Estimated completion

01 Dec 2026

Biomarkers of B-vitamin Status and Gut Microbiome Composition

What is this study about?

As we get older, many of us start to notice changes in our bodies. Sometimes, the helpful bacteria living in our gut can change, which might be linked to feeling more run down or even affecting our mood. Getting enough of certain nutrients, like fibre and B-vitamins, is also super important for older adults, and sometimes our diets don't provide quite enough. Scientists think these nutritional gaps might play a role in why some older people experience increased inflammation or don’t feel as mentally sharp.

This study is looking into a new approach: a special fruit drink. This drink contains a type of fibre called inulin, which is a 'prebiotic'. Prebiotics are like food for good gut bacteria, helping them to grow and thrive. The drink might also contain B-vitamins, which are known to be important for both gut and brain health. We want to see if drinking this special drink for a few months can help improve the balance of gut bacteria, lower inflammation in the body, and make people feel better mentally.

Working with a food company, researchers have created this drink. They are now inviting people aged 50 and over to take part in a 12-week study. Participants will be given one of three types of drinks: one with just the inulin fibre, one with both inulin and B-vitamins, or a plain 'dummy' drink (placebo). This will help the researchers understand exactly what effects, if any, the ingredients in the drink have on people's health.

Key takeaways

Study explores a drink with fibre (inulin) and B-vitamins for gut and mood.
Aimed at adults aged 50 and over.
Hopes to improve gut bacteria, inflammation, and mental well-being.
Involves a 12-week trial with different drink types (some with active ingredients, some 'dummy').
Requires blood and stool samples, plus questionnaires about your health and feelings.

Who may be eligible?

This study is looking for healthy adults aged 50 or over who live independently in their own homes. To make sure the study results are clear, they are looking for people who don't usually eat or drink many foods that have extra B-vitamins added to them (like some breakfast cereals or fortified milks). Also, you shouldn't be taking any supplements that already contain B-vitamins, inulin (a type of fibre), or other 'probiotic' supplements aimed at gut health. It's important that you haven't recently had B12 injections and aren't taking medicines that could affect how your body uses B-vitamins.

There are also some health conditions that would prevent you from taking part. For example, if you have certain gut diseases like Crohn's disease or coeliac disease, or if you have a serious long-term illness like cancer or severe liver disease, this study might not be right for you. They also can't include anyone who is currently taking antibiotics, as these can significantly affect gut bacteria. All participants need to be able to understand the study information and agree to take part themselves.

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 50 years old or older?
Do you live independently at home?
Do you rarely eat or drink foods with added B-vitamins (like fortified cereals)?
Are you NOT currently taking B-vitamin, inulin, or probiotic supplements?
Do you NOT have serious gut or long-term diseases (like Crohn's, coeliac, cancer)?
Are you NOT currently taking antibiotics?

Answer every question to see your result.

What does participation involve?

If you decide to take part in this study, you'll be asked to drink a special functional drink every day for 12 weeks. You won't know if you're getting the drink with fibre, the drink with fibre and B-vitamins, or a plain 'dummy' drink (placebo) – this helps make the results fairer. Throughout the 12 weeks, you'll have a few appointments where researchers will check on your health, take some blood and stool samples (poo samples), and ask you questions about how you're feeling and your mental well-being. These measurements will help them understand the effects of the drink. The total duration of your active involvement in the study, including the follow-up, will be around 3 months.

Potential risks and benefits

Participating in research always has potential benefits and risks. You might not directly benefit from taking part, but your contribution will help scientists learn more about gut health, nutrition, and mental well-being in older adults, which could help many people in the future. Potential risks are generally low, mainly involving the minor discomfort of blood samples or potential mild stomach upset from the fibre, though this will be monitored. You are absolutely free 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.

Human Intervention Studies Unit
Verified postcode
Coleraine, United Kingdom· Recruiting

Common questions

What is 'inulin'?

Inulin is a type of fibre, found in foods like chicory root, that acts as food for good bacteria in your gut. It's called a 'prebiotic'.

Why are B-vitamins important?

B-vitamins are essential for many body functions, including energy levels, nervous system health, and can play a role in brain and gut health.

What does 'placebo-controlled' mean?

It means some people get the active drink, and others get a 'dummy' drink that looks and tastes the same but has no active ingredients. This helps researchers see the real effect of the active ingredients.

Will I know which drink I am getting?

No, you won't know if you're getting the active drink or the placebo. This is called 'double-blind' and helps keep the results unbiased.

How long will I be in the study?

You'll be asked to drink the special drink daily for 12 weeks, with a few visits over that period to check your progress.

How to find out more

Shane Gordon, PhD

S.Gordon2@ulster.ac.uk +44 28 7012 3035 Official trial record

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