Condition category
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Asthma is an inflammatory disorder that causes the narrowing of airways, increased production of mucus and therefore difficulty breathing. Asthma sufferers may experience shortness of breath, wheezing, tightness of the chest and a dry irritating cough. Asthma is a common condition that affects approximately 300 million people worldwide, in the UK 5.4 million people are currently recieving treatment. The NHS spend up to £1 billion a year for the care and treatment of those who have asthma.

This study will investigate how prebiotic supplementation affects asthma, by observing changes in quality of life, use of current medication and inflammation. Prebiotics are a carbohydrate that feed the ‘good bacteria’ in the gut, otherwise known as Probiotics. These bacteria have an important role in look after our immune system and a reduced number/activity of these ‘good bacteria’ may lead to development of asthma or increased severity of asthma. This study aims to increase our understanding of how the gut bacteria may affect asthma and the results may lead to a better understanding of the factors that might influence asthma and how these can be managed by targeting the diet.

Who can participate?
Adults diagnosed with asthma

What does the study involve?
Participants are randomly allocated into one of two groups. Group one are given a prebiotc supplement, known as B-GOS. Group two are given a placebo (dummy pill). Both groups will take the supplement, B-GOS, or placebo for 3 weeks. After this time, participants will continue as normal for two weeks, followed by another 3 weeks with either the placebo or B-GOS. Each participant will attend the laboratory for a lung function test, blood sample and to fill out questionnare before the start of each treatment; a total of 4 times over 8 weeks.

What are the possible benefits and risks of participating?
Participants may benefit from gaining a wider understanding into managing and controlling their asthma. Potential risks include possible discomfort when taking blood samples.

Where is the study located?
Nottingham Trent University, Clifton Campus (UK)

When does the study start and end?
June 2019 to June 2020

Who is the main contact.
Mr. Jacob Jayaratnasingam

Trial website

Contact information



Primary contact

Mr Jacob Jayaratnasingam


Contact details

Nottingham Trent University
Clifton Campus
Clifton Lane
NG11 8NS
United Kingdom
+44 (0)115 941 8418

Additional identifiers

EudraCT number

Nil known number

Nil known

Protocol/serial number

IRAS Application: 253339

Study information

Scientific title

The effects of Prebiotic Supplementation on Quality of Life, Control of Asthma, and Markers of Systemic Inflammation in Adults with Asthma. A Double-Blind, Placebo-Controlled, Crossover Trial.



Study hypothesis

Prebiotic supplementation will lead to significant changes in pro-inflammatory/anti-inflammatory markers in the blood.

Ethics approval

Approval pending, East Midlands - Nottingham 1 Research Ethics Committee (The Old Chapel, Royal Standard Place, Nottingham, NG1 6FS; 0207 104 8104;, ref: 19/EM/0088

Study design

Single centre double-blind placebo-controlled intervention crossover trial

Primary study design


Secondary study design

Randomised cross over trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use contact details to request a participant information sheet.


Asthma, steps 1-4 according to the Birtish Thoracic Society Guidelines (BTS)


Block randomisation will be used to randomise subjects into equal groups. At baseline, both groups will give a blood sample, undergo lung function tests, complete a 4-day food diary and asthma related questionnaires. The same measurements will be completed following prebiotic or placebo supplementation after 3-weeks. The measurements will then be completed again following a 2-week washout period. Groups will then crossover research arms and continue a 3 week supplementation period with either the prebiotic or placebo, before the final measurement. Supplements will be randomised by an independent party into 'X' and 'Y', ensuring the study is double blind.

Blood samples will be analysed using flow cytometry and mass spectrometry to observe specific and general changes in protein expression.

Intervention type



Drug names

Primary outcome measure

Changes in FOXP3 expression by regulatory T cells in adults with asthma, following a prebiotic intervention crossover trial. Measured using flow cytometry at 4 timepoints as aforementioned, baseline, prebiotic, washout and placebo.

Secondary outcome measures

1. Changes in asthma control, and frequency of reliever medication in adults with asthma following prebiotic supplementation. Measured at 4 time points, baseline, prebiotic, washout and placebo; using the Asthma Control Questionnaire.
2. Changes in perception of asthma control (e.g. reduced frequency/severity of symptoms) following prebiotic supplementation. Measured at 4 time points, baseline, prebiotic, washout and placebo; using the Asthma Control Test.
3. Changes in quality of life following prebiotic supplementation. Measured at 4 time points, baseline, prebiotic, washout and placebo; using the Asthma Quality of Life Questionnaire

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1.18-50 years of age at the date of your first visit.
2. Body mass index (BMI) of 18.5-25 kg∙m2 (we can work this out for you using your height and body weight).
3. Non-smoker.
4. Asthma is defined as Steps 1 to 4 based on British Thoracic Society guidelines.
5. On a stable asthma treatment for 3 months
6. Current medication prescription from your GP if diagnosed with asthma (e.g. maintenance and reliever inhalers).
7. Be able and willing to follow all trial requirements.
8. Disclose any nutritional supplements you take to the researcher, to determine whether these may be considered as ‘exclusion criteria’.

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Suffer from asthma but do not have a current medication prescription from your GP (e.g. maintenance and reliever inhalers).
2. Regularly consume Omega-3 supplements, and/or eat high levels of Omega-3 (e.g. more than 1-2 portions of oily fish such as salmon or mackerel a week).
3. Take aspirin or other non-steroidal anti-inflammatory drugs such as ibuprofen once a day on 5 of of the 7 days of the week.
4. Pregnant or planning a pregnancy during the time of the study (on each visit you will be asked to complete a pregnancy test if you are within childbearing age).
5. Consumed prebiotics and/or probiotics (supplements), drugs that affect gastrointestinal mobility or laxatives in the 4 weeks before signing the consent form.
6. Daily dose of anti-histamine, which you could not temporarily avoid for 72 hours before each testing session without exacerbation of symptoms.
7. Vegetarian or vegan diet.
8. Previously diagnosed with chronic obstructive pulmonary disease (COPD), emphysema, chronic bronchitis, or similar respiratory (breathing-related) illness.
9. Admitted to hospital during the past 12 months for your asthma.
10. History of heart failure, pulmonary hypertension, embolism, or other pulmonary heart disease.
11. History of recurrent chest infections.
12. Acute infection in the last four weeks, and/or major operation in the past four months.
13. History of gastrointestinal drug reaction.
14. Taken antibiotics in the past 3 months.
15. History or current evidence of gastrointestinal disease (e.g. chronic constipation, diarrhoea, irritable bowel syndrome, Chrohn’s disease).
16. Recently taken part in other research projects. Please notify the chief investigator.
17. Lactose intolerant.
18. Regularly take antioxidant supplements, such as beta-carotene, vitamin A, vitamin C, vitamin E, lutein and selenium. Standard multivitamin and mineral supplements are acceptable; however, If a single antioxidant supplement (e.g. Vitamin C), is more than the recommended daily DRV’s this must be checked with the chief investigator.

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Nottingham Trent University Clifton Campus
Nottingham Trent University Clifton Campus Clifton Lane Clifton Nottingham
NG11 8NS
United Kingdom

Sponsor information


Nottingham Trent University

Sponsor details

Clifton Campus
Clifton Lane
United Kingdom
+44 (0)115 941 8418

Sponsor type




Funder type


Funder name

Nottingham Trent University

Alternative name(s)


Funding Body Type

private sector organisation

Funding Body Subtype

Universities (academic only)


United Kingdom

Results and Publications

Publication and dissemination plan

Following study completion, it is planned the results will be published in 2021 in a high-impact peer-reviewed journal

IPD sharing statement:
The current data sharing plans for this study are unknown and will be available at a later date

Intention to publish date


Participant level data

To be made available at a later date

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

05/04/2019: Internal review. 29/03/2019: Trial’s existence confirmed by IRB