Effects of Different Bread Types in NCGS

Study Purpose

Although wheat and gluten containing food products are generally considered to be healthy, a large number of individuals in the general population reduces or limits their intake and/or replaces wheat by other grains because of possible symptoms. This non-coeliac gluten/wheat sensitivity (NCGS/NCWS) is accompanied by a range of (extra-)intestinal complaints soon after consuming wheat or gluten, which improve after wheat/gluten withdrawal. Evidence for a biological mechanism and for the exact contributing compound is limited. Furthermore, the impact of grain type, bread processing and the resulting compositional changes in bread on gastrointestinal tolerability in NCGS/NCWS is unclear, especially as consumed part of a typical daily human diet. The objective of this study is to investigate the effects of well-characterised breads on (extra-)intestinal symptoms, gut microbiota composition and activity, metabolite profiles, and innate immune function in individuals with NCGS using a three-arm randomized cross-over design. Subjects are required to adhere to a gluten-free diet during the trial. The investigators hypothesize that grain type and processing will have a different effect on the primary outcomes.

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 18 Years - 70 Years
Gender All
More Inclusion & Exclusion Criteria

Inclusion Criteria:

  • - Develops of self-reported GI symptoms after a single intake of bread or gluten- containing products; - Age between 18-70 years; - Avoiding or restricting gluten-containing foods for at least 1 week before start of as well as during the study (based on a gluten-free dietary compliance questionnaire of Biagi et al.
(only group 2, 3 and 4 of the Biagi will be eligible);
  • - Asymptomatic or only mildly symptomatic (overall) GI symptoms score with VAS < 30mm) while on the gluten-free/gluten-restricted diet; - Must have a freezer (-18ºC) to store the study breads during the study; - Willing and able to give written informed consent and to understand, participate and comply with the research project requirements.

Exclusion Criteria:

  • - Medical history of coeliac disease, wheat allergy, inflammatory bowel disease, presence of an organic gastrointestinal (GI) disease (such as inflammatory bowel disease) or other disease which may interfere with NCGS symptoms (upon judgment of the physician-clinical investigator (Dr.
Keszthelyi, Gastroenterologist MUMC+));
  • - Previous major abdominal surgery or radiotherapy interfering with gastrointestinal function: - Uncomplicated appendectomy, cholecystectomy and hysterectomy allowed unless within the past 6 months; - Other surgery may be allowed based upon judgment of the physician-clinical investigator (Dr.
Keszthelyi, Gastroenterologist MUMC+), who will decide on inor exclusion based upon the surgery applied;
  • - Use of medication potentially influencing gastrointestinal function and/or NCGS symptoms is allowed, provided that dosing has been stable for ≥ 1 month before enrolment; - Use of antibiotics within 90 days prior to the study; - Administration of probiotic, prebiotic supplements, investigational drugs or participation in any scientific intervention study, which may interfere with this study (to be decided by the principle investigator), in the 14 days prior to the study; - Use of immunosuppressive drugs within 90 days before enrolment; - Excessive use of alcohol (>15 alcoholic units per week), or other drugs; - Plan to lose weight or follow a specific weight loss diet within the study period; - Current malignancy; - Pregnancy or breastfeeding; - Participation in any scientific intervention study, which may interfere with this study; - Insufficient fluency of the Dutch language.

Trial Details

Trial ID:

This trial id was obtained from ClinicalTrials.gov, 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.

Maastricht University
Principal Investigator

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

Daisy MAE Jonkers, Prof., PhD
Principal Investigator Affiliation Maastricht University
Agency Class

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

Overall Status Recruiting
Countries Netherlands

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

Non-Coeliac Gluten Sensitivity (NCGS), Non-Coeliac Wheat Sensitivity (NCWS)
Arms & Interventions


Active Comparator: Bread types 1 & 2

Daily consumption of 5 slices of allocated bread type for 3 consecutive days.

Active Comparator: Bread types 3 & 4

Daily consumption of 5 slices of allocated bread type for 3 consecutive days.

Active Comparator: Bread types 5 & 6

Daily consumption of 5 slices of allocated bread type for 3 consecutive days.


Dietary Supplement: - Different types of bread

Three-arm randomized cross-over study. All subjects start with a run-in period of 3 days, thereafter they will receive two different types of bread in a randomized order for 3 consecutive days, with a wash-out period of 11 days in between. After each period, biological samples will be collected.

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

Maastricht University, Maastricht, Netherlands




Maastricht University

Maastricht, ,

Site Contact

Marlijne CG de Graaf, 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.

PO Box 544, Ambler, PA 19002

Phone: 215-325-1306

Toll-Free: 844-856-6692

Press Room / Media Inquiries

Contact Information

The information found on this website is not intended to be a replacement or substitute for professional medical treatment or for professional medical advice relative to a specific medical condition. We urge you to always seek the advice of your physician. There is no replacement for personal medical treatment and advice from your personal physician.