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.
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.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
40
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.
Centre de Recherche sur Volontaires
Bobigny, France
RECRUITINGCentre de Recherche sur Volontaires (CRV)
Bobigny, Île-de-France Region, France
NOT_YET_RECRUITINGIntensity 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.
Time frame: Scores at Day 0 [D0] and Day 15 [D15]
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.
Time frame: Scores at Day 0 [D0] and Day 15 [D15]
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.
Time frame: Scores of the two questionnaires at Day [D0] and Day [D15]
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.
Time frame: Scores at Day 0 [D0] and Day 15 [D15]
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.
Time frame: These scores are measured at Day 0 [D0], Day 8 [D8] and Day 15 [D15].
Evaluation of intestinal permeability
Intestinal permeability will be assessed by measuring serum zonulin levels and the urinary lactulose/mannitol ratio.
Time frame: Measured on Day D0 [D0] and Day 15 [D15]
Evaluation of intestinal inflammation
Intestinal inflammation will be assessed by measuring serum LBP and faecal calprotectin.
Time frame: 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].
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.
Time frame: Determined in stool samples collected at visit 0 [V0], on Day -1 [D-1] and Day 14 [D14]
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).
Time frame: From the enrollment (visit 0 [V0]) to the end of the study (Day 15 [D15])
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
Time frame: Measured at 0; 0.5; 1; 1.5; 2; 2.5 and 3 hours after test meal
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
Time frame: Measured at 0; 0.5; 1; 1.5; 2; 2.5 and 3 hours after test meal
Substrate oxidation rates
Fat and glucose oxidation assessed by measuring respiratory exchanges using indirect calorimetry
Time frame: Measured at 0; 0.5; 1.5 and 2.5 hours after test meal
H2 concentrations in exhaled air
H2 concentration in air measured every 30 minutes for 3 hours after test meal
Time frame: Measured at 0; 0.5; 1; 1.5; 2; 2.5 and 3 hours after test meal
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