RecruitingNAINTERVENTIONAL

Microbiota Mediated Flavonoid Metabolites for Cognitive Health

This research is investigating how certain natural compounds called 'polyphenols', found in foods, might help keep your brain healthy as you age. We're focusing on people over 50 who might be at higher risk of memory and thinking problems. The study believes that the helpful effects of these plant compounds on the brain are partly due to how your gut bugs (microbiota) break them down. We're also looking at how these gut bugs affect other body chemicals, like certain bile acids, which could also play a role in brain health. Understanding these connections could lead to new ways to prevent or delay conditions like Alzheimer's disease by looking at diet and gut health.

At a glance

Status

Recruiting

Phase

Sponsor

University of Ulster

Enrolment target

100

Start

25 Nov 2025

Estimated completion

01 Jan 2028

Cognitive Decline Cognitive Dysfunction

What is this study about?

As people get older, memory and thinking problems can become more common. This study is exploring why some people might be more protected than others, especially looking at the effects of a healthy diet.

Researchers are particularly interested in certain plant compounds called 'polyphenols', which are found in fruits, vegetables, and other healthy foods, like those in a Mediterranean diet. We already know that eating a lot of these polyphenols might help prevent or slow down memory issues. But it's not just about what you eat; it's also about how your body uses it. This is where your gut bugs – the trillions of tiny organisms living in your digestive system – come in. They play a big part in breaking down these plant compounds into other helpful substances that can then travel around your body, including to your brain.

This study aims to discover exactly how these gut bugs help turn food polyphenols into brain-boosting chemicals. We're also looking at other chemicals in your body, called bile acids, which are affected by your gut bugs and also seem to be connected to brain health. By understanding these links between diet, gut bugs, and brain health, especially in people over 50 who might be at a higher risk of memory problems, we hope to find new ways to keep brains healthy and potentially delay conditions like Alzheimer's disease.

Key takeaways

This study explores how diet and gut bacteria may protect brain health in older adults.
It focuses on natural plant compounds called polyphenols.
Participation involves taking a supplement (or placebo) and various health checks.
Aims to understand how gut bugs process food to influence the brain.
Could help find new ways to prevent conditions like Alzheimer's disease.

Who may be eligible?

This study is looking for healthy volunteers aged 50 or over. To be eligible, you should have a Body Mass Index (BMI) of 25 or higher. You'll also need to have a family history of Alzheimer's disease (meaning a very close family member like a parent or sibling had it), which means you might be at a slightly higher risk yourself. Typically, you should also be someone who usually eats a 'Western diet', which often includes more processed foods and less healthy options.

There are also some reasons why you might not be able to join. For example, if you already have memory problems or conditions like dementia, or if you have certain mental health conditions. You also can't take part if you've recently used probiotics or antibiotics, or if your regular medications have changed in the last three months. People with certain health conditions, allergies to the study products, or who are pregnant or breastfeeding, will also not be able to participate. Because an MRI scan is part of the study, you shouldn't have any metal in your body that could cause issues with the scanner, or suffer from severe claustrophobia.

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 have a close family member (like a parent) who had Alzheimer's disease?
Do you mostly eat a 'Western-style' diet (high in processed foods)?
Have you *not* had any major changes to your medication in the last 3 months?
Have you *not* taken antibiotics or probiotics in the last month?
Are you comfortable with having an MRI scan?

Answer every question to see your result.

What does participation involve?

Taking part in this study will involve several visits over a period of time, though the exact number and duration aren't specified. You will receive either a polyphenol supplement or a dummy pill (placebo supplement). You won't know which one you're taking. Researchers will monitor your health and gather information through various tests and assessments. These will likely include blood tests, diet questionnaires, and potentially brain scans (MRI). You'll also need to be willing to follow the study instructions carefully and attend all scheduled appointments. The study aims to understand how your diet and gut health affect your brain over time.

Potential risks and benefits

By taking part, you could be helping researchers understand more about how diet and gut health can protect the brain, which could benefit many people in the future. While the supplement is thought to be safe, there's always a small chance of unexpected side effects, and some tests, like blood draws or MRI scans, carry their own minor risks. Your well-being is very important, 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.

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

Common questions

What are polyphenols?

Polyphenols are natural chemicals found in many plants, especially in fruits, vegetables, and whole grains. They are thought to have many health benefits, including for your brain.

What is the 'gut microbiome'?

The gut microbiome refers to the trillions of tiny living bugs, like bacteria, that live in your digestive system. They play a big role in your overall health, including how you digest food and even how your brain works.

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

No, this is a 'blinded' study, meaning neither you nor the research team will know if you're getting the active supplement or the placebo. This helps make the study results more reliable.

What is 'cognitive decline'?

Cognitive decline means that your memory, thinking, and reasoning skills are not as sharp as they used to be. It can be a natural part of ageing but can also be a sign of conditions like Alzheimer's.

What is an MRI scan?

An MRI scan uses strong magnets and radio waves to create detailed pictures of the inside of your body, including your brain. It's a common and safe procedure.

How to find out more

Chris Gill, PhD

c.gill@ulster.ac.uk +44 28 7012 3181 Official trial record

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