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Intolerance to "Conventional" BreadTOLERBREADNCT07568223

Tolerance to an Artisanal Bread in a Population Intolerant of the Conventional Bread and Study of Associated Markers

A study testing Artisanal Bread in people with Intolerance to "Conventional" Bread, run by Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement at 2 sites in France.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

The objective of this study is to evaluate the effect of consuming an "artisanal" bread for 15 days on gastrointestinal symptoms in individuals intolerant to "conventional" bread. Read more about this study

Who is it for?
Ages 18 to 65 yearsHealthy volunteers can take part
Conditions the study is for
Intolerance to "Conventional" Bread
What is being tested?
Artisanal Bread
Could I receive a placebo?
No, everyone receives an active treatment
How many people
40 participants
Where
2 sitesFrance
Study dates
28 Jan 2026to Jun 2027
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 65 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Normal weight (18 < BMI < 25 kg.m-2)
  • Male or female
  • 18 to 65 years old
  • Adults reporting intolerance to "conventional" bread
  • Absence of celiac disease
  • Affiliated to a social security scheme
  • Free, informed and express consent

Who cannot join

  • People under protective supervision: legal guardianship, tutorship or curatorship
  • People with eating disorders (anorexia, bulimia, binge eating)
  • Any known food allergy
  • Women who are pregnant or potentially pregnant (based on a positive urine pregnancy test at inclusion)
  • Breastfeeding women
  • Alcohol abuse (>2 drinks/day). At the time of inclusion, the investigator will assess whether the participant exhibits harmful alcohol consumption
Show all 9Show fewer
  • Untreated hypertension, uncontrolled diabetes, or diseases of the digestive tract (excluding functional intestinal disorders), liver, kidneys, or severe heart disease. The investigator will assess the presence of these conditions on standard clinical criteria and the participants' self-reported medical history at the time of inclusion
  • Participation in a clinical study in the three months preceding the study
  • Absence of express consent

Trial locations and contacts

2 sites in 1 country. Contact the study team or a site near you to ask about taking part.

France2 sites, 2 recruiting
  • Centre de Recherche sur Volontaires

    Bobigny, 93000

    Suzette Maurinier, suzette.maurinier@aphp.fr

    Mourad Benallaoua, mourad.benallaoua@aphp.fr

    Recruiting
  • Centre de Recherche sur Volontaires (CRV)

    Bobigny, Île-de-France Region, 93000

    Suzette Maurinier, +331 48 95 74 33, suzette.maurinier@aphp.fr

    Fabien Wuestenberghs

    Not yet recruiting

Other trials in France

About this study

The objective of this study is to evaluate the effect of consuming an "artisanal" bread for 15 days on gastrointestinal symptoms in individuals intolerant to "conventional" bread.

"Conventional bread" refers to bread made with refined wheat flour (ash = 0.55% of dry matter), containing gluten, and leavened with baker's yeast (Saccharomyces cerevisiae). "Artisanal bread" refers to bread made with whole wheat flour (ash = 1.50% of dry matter) from an ancient durum wheat variety (Russello) and leavened with sourdough.

Read the detailed description

Abbreviations:

  • GSRS-IBS: Gastrointestinal Symptom Rating Scale for Irritable Bowel Syndrome
  • GIQLI: Gastrointestinal Quality of Life Index
  • HADS: Hospital Anxiety and Depression Scale
  • FSS: Fatigue Severity Scale
  • LBP: Lipopolysaccharide-Binding Protein

Inclusion Visit (visit 0 [V0])

At the inclusion visit (V0) at Avicenne Hospital (Bobigny), participants will receive study instructions and materials. They will have up to 15 days to:

  • Complete questionnaires (modified GSRS-IBS, Bristol Stool Scale, GIQLI, HADS, FSS)
  • Collect a baseline stool sample, stored at -18°C at home until their first hospital visit (V1).

Wash-out phase (Day-15 [D-15] to Day 0 [D0]):

Participants will follow a gluten-free and low-fructan diet for 15 days. During this period:

  • Daily food intake will be recorded in a diary, with meal photos sent to the research team via a dedicated email
  • On D-8, participants will complete the modified GSRS-IBS and Bristol Stool Scale.
  • On D-1, participants will perform a 24-hour urine collection after ingestion of lactulose (10g) and mannitol (10g) in 200 mL water, divided into three containers:
  • First morning urine
  • 0-5 h collection after sugar ingestion (fasting except water)
  • 5-24 h collection Stool will also be collected on D-1 and stored at 4°C until V1.

First investigation day (Day 0 [D0] - V1):

At 9 a.m., participants arrive the Clinical Research Center (at Avicenne Hospital) with their stool and urine samples.

After completing the questionnaires (modified GSRS-IBS, GIQLI, HADS, FSS, and Bristol Stool Scale), a venous catheter will be inserted for blood sampling.

A 10 mL blood sample will be collected before the test meal. Participants will then consume the test meal (105 g of "artisanal" bread with water).

Postprandial blood samples (2 mL each) will be collected every 30 minutes for 3 hours (total blood volume: 22 mL) The modified GSRS-IBS questionnaire will be completed every hour during the postprandial period If a bowel movement occurs during the visit, the stool sample collected at that time may be used to replace the one collected the previous day.

Intervention phase (D1 to D14):

Participants will continue the same gluten-free, low-fructan diet, with the addition of the "artisanal" bread, which will serve as the sole source of gluten source and the main source of fructans.

  • D1: 75 g of bread
  • D2: 100 g of bread
  • D3-14: 125 g of bread daily (≈ 8.5 g gluten, <1.2 g fructans) Bread consumption may be distributed throughout the day. On D8, participants will again complete the modified GSRS-IBS and Bristol Stool Scale.

Second investigation day (D15 - V2):

On D14, participants will repeat the 24-hour urine and stool collection as previously described. On D15, they will return to the research center and undergo the same procedures as V1.

Measurements:

  • Questionnaires: modified GSRS-IBS (gastrointestinal symptoms), GIQLI, HADS, FSS.
  • Blood: LBP (marker of inflammation), zonulin (marker of intestinal permeability), glucose, insulin.
  • Urine: lactulose and mannitol, with calculation of the lactulose/mannitol ratio as a marker of intestinal permeability.
  • Stool: microbial community analysis (microbiota) and fecal calprotectin (marker of inflammation). Baseline stool samples (before wash-out phase) will also be used to inoculate an artificial colon model for later investigation of the effects of bread on the microbiota.
Being tested
Artisanal Bread
Keywords
Bread, Wholemeal flour, Ancient wheat, Sourdough, Gluten, FODMAPs, Digestive tolerance, Postprandial metabolism, Inflammation, Intestinal permeability, Microbiota
Medical subject headings
Inflammation

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Artisanal BreadDietary supplement

    During the second part of the study (from Day 1 [D1] to Day 14 [D14]), participants will consume the "artisanal" bread on a daily basis.

    Dose: D1 = 75g; D2 = 100g; from D3 to D14: 125g/day On D0 and D15, volunteers will come to the hospital for 3 hours of postprandial testing.

Study groups in NCT07568223
Study groupRoleWhat they receive
Artisanal BreadExperimental"Artisanal" bread is made with wholemeal flour (ash = 1.50% of dry matter) from an ancient durum wheat (Russello variety) and leavened with sourdough. "Artisanal" bread contains 6.8g of gluten and less than 1g of frutans per 100g.
Receives: Dietary Supplement: Artisanal Bread

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Intensity of gastrointestinal symptoms

    The severity of gastrointestinal symptoms will be assessed using a score from the modified GSRS-IBS questionnaire used in this study.

    This score consists of 13 questions ranging from 1 (Not at all) to 7 (Very severely) on a Likert scale. Thus, the total score can range from 13 to 91, with higher scores indicating more severe gastrointestinal symptoms and, consequently, lower tolerance.

    The scores obtained before and after the diet including the "artisanal" bread will be compared.

    Measured: Scores at Day 0 [D0] and Day 15 [D15]

Secondary outcomes (12)
  1. Intensity of gastrointestinal and extraintestinal symptoms

    The intensity of gastrointestinal and extra-intestinal symptoms will be assessed using the total score of the modified version of the GSRS-IBS questionnaire.

    Scores obtained before and after the diet including the "artisanal" bread will be compared.

    The score is measured on a 7-point Likert scale, ranging from 1 (Not at all) to 7 (Very severely). The questionnaire consists of 28 questions, so total scores can range from 28 to 196, with higher scores indicating more severe gastrointestinal and extra-intestinal symptoms and, therefore, lower tolerance.

    Measured: Scores at Day 0 [D0] and Day 15 [D15]

  2. Validity of the modified GSRS-IBS

    Correlations between the scores from the GSRS-IBS and the modified GSRS-IBS used in this study will be analyzed.

    The GSRS-IBS score can be obtained from the modified GSRS-IBS questionnaire. This questionnaire consists of 7-point Likert scale ranging from 1 (No discomfort at all) to 7 (Very severe discomfort) for 13 items. The total score therefore ranges from 13 to 91. An increase in this score indicates greater gastrointestinal discomfort and, consequently, lower tolerance.

    The modified GSRS-IBS questionnaire comprises 28 items scored on a 7-point Likert scale, ranging from 1 (Not at all) to 7 (Very severely). Thus, the total score of this questionnaire ranges from 28 to 196. An increase in this score indicates greater gastrointestinal symptoms and, consequently, lower tolerance.

    These two scores will be compared, and their correlation analyzed.

    Measured: Scores of the two questionnaires at Day [D0] and Day [D15]

  3. Comparison between volunteers' perceived tolerance of "artisanal" bread and measured tolerance

    In addition to the intensity scores calculated for each symptom (the sum of which constitutes an objective total score), participants will give a global subjective assessment of their tolerance to the "artisanal" bread using a scale from 0 (absence of symptoms) to 10 (extremely intense symptoms). The objective and subjective scores will then be compared, and their correlation analyzed.

    Measured: Scores at Day 0 [D0] and Day 15 [D15]

  4. Clinical profile of response to the "artisanal" bread

    Individual symptoms will be grouped into symptom groups (pain, reflux, indigestion, diarrhea and constipation). A score will be calculated for each groupe, and these scores will be compared.

    Measured: These scores are measured at Day 0 [D0], Day 8 [D8] and Day 15 [D15].

  5. Evaluation of intestinal permeability

    Intestinal permeability will be assessed by measuring serum zonulin levels and the urinary lactulose/mannitol ratio.

    Measured: Measured on Day D0 [D0] and Day 15 [D15]

  6. Evaluation of intestinal inflammation

    Intestinal inflammation will be assessed by measuring serum LBP and faecal calprotectin.

    Measured: Serum LBP : measured on Day 0 [D0] and Day D15 [D15] Fecal calprotectin : measured in stool samples collected at Day-1 [D-1] and Day 14 [D14].

  7. Microbiota composition

    The relative abundance of bacterial genera in stool samples at the end of each diet (with and without bread) will be compared.

    Stool samples will also be collected at inclusion (visit 0 [V0]) to determine the baseline microbiota and to inoculate an in vitro artificial colon model.

    Measured: Determined in stool samples collected at visit 0 [V0], on Day -1 [D-1] and Day 14 [D14]

  8. Tolerance profiles for "artisanal" bread

    Exploration of tolerance profiles to "artisanal" bread without a priori, and their characterization based on clinical data (questionnaires) and biological markers (inflammation, intestinal permeability, and microbiota).

    Measured: From the enrollment (visit 0 [V0]) to the end of the study (Day 15 [D15])

  9. Postprandial glucose responses measured after consumption of the test meal ("artisanal bread")

    Blood glucose levels measured every 30 minutes for 3 hours after the test meal

    Measured: Measured at 0; 0.5; 1; 1.5; 2; 2.5 and 3 hours after test meal

  10. Postprandial insulin responses measured after consumption of the test meal ("artisanal bread")

    Blood insulin levels measured every 30 minutes for 3 hours after the test meal

    Measured: Measured at 0; 0.5; 1; 1.5; 2; 2.5 and 3 hours after test meal

  11. Substrate oxidation rates

    Fat and glucose oxidation assessed by measuring respiratory exchanges using indirect calorimetry

    Measured: Measured at 0; 0.5; 1.5 and 2.5 hours after test meal

  12. H2 concentrations in exhaled air

    H2 concentration in air measured every 30 minutes for 3 hours after test meal

    Measured: Measured at 0; 0.5; 1; 1.5; 2; 2.5 and 3 hours after test meal

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted5 May 2026
  2. Study start28 Jan 2026
  3. Primary completionDec 2026 (estimated)
  4. Study completionJun 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
40 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07568223
Sponsor's protocol ID
TOLERBREAD
Acronym
TOLERBREAD
Status last verified
May 2026
First submitted
21 Jan 2026
Last updated
5 May 2026
Results posted
No
FDA-regulated drug
No
FDA-regulated device
No

Questions about this trial

What is this clinical trial studying?

A study testing Artisanal Bread in people with Intolerance to "Conventional" Bread, run by Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement at 2 sites in France.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 7 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 5 May 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in France. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Fabien Wuestenberghs (+330148952276, fabien.wuestenberghs@aphp.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Intensity of gastrointestinal symptoms (time frame: Scores at Day 0 [D0] and Day 15 [D15]). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 May 2026.

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