The Ecological Role of Yeasts in the Human Gut

Study Purpose

Irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) (categorised into Crohn's disease (CD) and ulcerative colitis (UC)) are chronic gut disorders with debilitating symptoms that profoundly impact quality of life, healthcare systems and the economy through lost work days. IBS is common with a prevalence of up to 22%, whereas IBD has a prevalence of 0.3% for CD and 0.5% for UC in Europe. Despite a suggested immunological and genetic aspect of IBD, the causes of IBS and IBD are unknown, however, both have been linked to yeasts in the gut. Due to their lower abundance (constituting only around 0.1% of the total microorganisms in the gut) yeasts have been less studied than bacteria. More recently, significantly altered diversity and composition of yeasts have been identified in IBS and IBD but further investigation is required to fully develop the role of yeasts in the gut. This observational study will assess yeasts and their function in the gut, comparing diseased subjects with healthy controls. The overall aim is to determine if yeasts could be targeted as a potential therapeutic for IBS and IBD to provide relief to sufferers as well as reducing the burden on healthcare systems.

Recruitment Criteria

Accepts Healthy Volunteers

Healthy volunteers are participants who do not have a disease or condition, or related conditions or symptoms

Study Type

An interventional clinical study is where participants are assigned to receive one or more interventions (or no intervention) so that researchers can evaluate the effects of the interventions on biomedical or health-related outcomes.

An observational clinical study is where participants identified as belonging to study groups are assessed for biomedical or health outcomes.

Searching Both is inclusive of interventional and observational studies.

Eligible Ages 20 Years - 60 Years
Gender All
More Inclusion & Exclusion Criteria

Inclusion Criteria:

  • - Aged 20-60 years old.
  • - Either healthy or diagnosed with a gut disorder: Irritable Bowel Syndrome (IBS) or Inflammatory Bowel Disease (IBD) which may include Crohn's disease or ulcerative colitis.
  • - In good general health.
  • - Provided written informed consent and willing to participate in this study.

Exclusion Criteria:

  • - Received antibiotics in the previous six months.
  • - Consume prebiotics or probiotics on a regular basis (at least 3 times per week) in the last 2 weeks or intend to throughout the course of the study.
(Examples of these include: Multibionta multivitamins, Danone Actimel yoghurt drink; Danone Activia yoghurt; Yakult fermented milk drink; Kellogg's Rice Krispies multigrain and Muller Vitality yoghurts/drinks).
  • - Current use of immunosuppressive drugs.
  • - Use of other medication which affects gastrointestinal motility and/or gut discomfort.
  • - History of alcohol or drug misuse.

Trial Details

Trial ID:

This trial id was obtained from, a service of the U.S. National Institutes of Health, providing information on publicly and privately supported clinical studies of human participants with locations in all 50 States and in 196 countries.


Phase 1: Studies that emphasize safety and how the drug is metabolized and excreted in humans.

Phase 2: Studies that gather preliminary data on effectiveness (whether the drug works in people who have a certain disease or condition) and additional safety data.

Phase 3: Studies that gather more information about safety and effectiveness by studying different populations and different dosages and by using the drug in combination with other drugs.

Phase 4: Studies occurring after FDA has approved a drug for marketing, efficacy, or optimal use.

Lead Sponsor

The sponsor is the organization or person who oversees the clinical study and is responsible for analyzing the study data.

Grace Ward
Principal Investigator

The person who is responsible for the scientific and technical direction of the entire clinical study.

Principal Investigator Affiliation N/A
Agency Class

Category of organization(s) involved as sponsor (and collaborator) supporting the trial.

Overall Status Recruiting
Countries United Kingdom

The disease, disorder, syndrome, illness, or injury that is being studied.

Irritable Bowel Syndrome, Inflammatory Bowel Diseases, Gastrointestinal Disease
Arms & Interventions


: Healthy

Healthy participants are those without IBS, IBD or any other gastrointestinal disorder

: Irritable bowel syndrome (IBS)

Participants with Rome IV diagnosed IBS

: Inflammatory bowel disease (IBD)

Patients with IBD - either ulcerative colitis (UC) or Crohn's disease (CD)


Contact a Trial Team

If you are interested in learning more about this trial, find the trial site nearest to your location and contact the site coordinator via email or phone. We also strongly recommend that you consult with your healthcare provider about the trials that may interest you and refer to our terms of service below.

International Sites

University of Reading, Reading, Berkshire, United Kingdom




University of Reading

Reading, Berkshire, RG6 6AH

Site Contact

Grace Newland, MSc


The content provided on clinical trials is for informational purposes only and is not a substitute for medical consultation with your healthcare provider. We do not recommend or endorse any specific study and you are advised to discuss the information shown with your healthcare provider. While we believe the information presented on this website to be accurate at the time of writing, we do not guarantee that its contents are correct, complete, or applicable to any particular individual situation. We strongly encourage individuals to seek out appropriate medical advice and treatment from their physicians. We cannot guarantee the availability of any clinical trial listed and will not be responsible if you are considered ineligible to participate in a given clinical trial. We are also not liable for any injury arising as a result of participation. For a full description of terms please refer to our Terms, Conditions & Privacy.