RecruitingNAINTERVENTIONAL

Dietary Fibres on Gut Fermentation

This research wants to understand how different types of fibre work together in your gut and affect your digestion. Many people don't eat enough fibre, but some types can cause tummy upset like bloating and gas if you have a lot at once. This study is testing if combining a fast-acting fibre with a slow-acting one, or taking the fast-acting fibre in two smaller amounts instead of one big dose, can help reduce these uncomfortable feelings. The aim is to find ways to get all the benefits of fibre without the usual tummy troubles. It involves healthy adults measuring gas and comfort after eating special meals.

At a glance

Status

Recruiting

Phase

Sponsor

University of Bath

Enrolment target

Start

26 Aug 2026

Estimated completion

27 Aug 2027

Healthy Adult

What is this study about?

This research study is looking into how different types of fibre affect your gut and digestion. Fibre is really important for keeping your gut healthy, but sometimes eating a lot of certain fibres can cause bloating and gas. This happens because tiny living things (bacteria) in your gut break down fibre, which can create gas.

Researchers are interested in two specific types of fibre: one that breaks down quickly in your gut (called FOS) and another that breaks down slowly (called soluble corn fibre). FOS is great because it helps boost good gut bacteria, but it can cause a lot of gas if you have too much at once. Soluble corn fibre is easier on your tummy but might not give the same quick benefits. This study wants to find out if combining these fibres, or having the fast-acting one in two smaller amounts instead of one large dose, can give you the benefits without the discomfort.

The main goal is to see if these different ways of taking fibre can reduce gas and tummy upset, while still making sure your gut gets all the good things fibre offers. Ultimately, they hope to find better ways for people to get enough fibre in their diet comfortably.

Key takeaways

Aims to understand how different fibres affect digestion and gut comfort.
Tests if combining fibres or splitting doses can reduce tummy upset.
Involves healthy adults (18-85) with regular bowel habits.
Requires 3 visits, fasting, special meals, breath tests, and comfort surveys.
Could help develop better ways to enjoy fibre's benefits without discomfort.

Who may be eligible?

To join this study, you need to be a healthy adult aged between 18 and 85 years old. You should usually have regular bowel movements – that means going to the toilet for a poo roughly 3 to 21 times a week. It's important that you don't have any long-term tummy problems like Irritable Bowel Syndrome (IBS) or Crohn's disease, and you shouldn't be pregnant or breastfeeding.

We also need to make sure you haven't recently taken certain medicines like antibiotics, or used special gut supplements, as these can change how your gut works. You can't have any known allergies to the fibres being tested in the study meals. Also, if you follow a very strict or unusual diet, you might not be able to take part as it could affect the study results.

Finally, you must be happy to follow the study instructions, including avoiding certain foods before your visits, fasting overnight, and eating the special test meals. You'll also need to be able to understand what the study involves and agree to take part in writing.

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 85 years old?
Do you usually have regular bowel movements (3-21 per week)?
Do you *not* have a long-term tummy condition like IBS or Crohn's?
Are you *not* pregnant, planning pregnancy, or breastfeeding?
Have you *not* taken antibiotics or certain gut supplements in the last 3 months?
Are you willing to follow dietary rules and fast overnight for visits?

Answer every question to see your result.

What does participation involve?

If you decide to take part, you will visit the research laboratory three times in total. There will be one week between each visit. Before each visit, you'll need to avoid certain foods and not eat anything overnight. During your visits, you'll eat a special breakfast and lunch that contain the different fibres.

Throughout the day, you'll need to give breath samples every 30 minutes. This helps researchers measure the gas produced by your gut bacteria. You'll also answer questions about how your tummy feels (your digestive comfort) every 30 minutes. For five days after each visit, you'll keep a diary about your bowel movements. The study doesn't involve taking any new medications, and there's no long-term follow-up beyond the last visit and diary keeping.

Potential risks and benefits

There are no direct medical benefits to you for taking part in this study. However, the information gathered could help us understand more about how fibre affects digestion, which might lead to better advice for others in the future. The main 'risk' is the possibility of experiencing some tummy discomfort, such as bloating or gas, when you eat the fibre-rich meals, as the study is designed to measure this. You might also find the dietary restrictions and fasting a bit inconvenient. Remember, taking part is completely voluntary. You can choose to leave the study at any time, for any reason, without it affecting your medical care.

Locations (1)

University of Bath
Verified postcode
Bath, United Kingdom· Recruiting

Common questions

What kind of fibres are being tested?

We are testing a fast-acting fibre called FOS and a slow-acting fibre called soluble corn fibre, both found in everyday foods.

Will I have to eat anything special?

Yes, on your study days you'll have specific breakfast and lunch meals containing the fibres. You'll also need to avoid certain foods beforehand.

What is 'gut bacterial fermentation'?

This is what happens when the bacteria in your gut break down food, like fibre. This process can produce gas, which we will measure.

How long will each visit take?

The information doesn't say exactly, but it involves eating meals and giving samples every 30 minutes for a period, so likely most of the day.

Is this study suitable for people with IBS?

No, this study is only for healthy adults without a history of long-term tummy problems like IBS.

How to find out more

Kuan-Yu Lin

kyl205@bath.ac.uk +44 7799056885 Official trial record

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