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RecruitingNCT07268508BariaGut TasteUpdated Apr 3, 2026

Impact of a Pro-diversity Gut Microbiota Diet After a Bariatric Surgery on Gut Microbiota, Eating Behaviour and Sensory Function

An interventional study of Nutritional counseling in Obesity (Disorder) and Bariatric Surgery, sponsored by Hospices Civils de Lyon. Recruiting at 3 sites in France. Open to participants aged 25 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-04-03.

Sponsored by Hospices Civils de Lyon · Not applicable, Interventional, and Prevention

From the registry’s dates

  • Started Nov 2025; still recruiting 11 months later.
Phase
Not applicable
Study type
Interventional
Enrollment
60
Allocation
Randomized
Ages
25 Years to 65 Years
Sex
All
01

Study summary

Bariatric surgery is the most effective treatment for long-term weight loss and reducing obesity-related health risks. It alters the gastrointestinal tract as well as metabolic and hormonal functions, influencing eating behaviour. However, weight loss outcomes and long-term maintenance vary between patients, likely due to changes in the gut microbiota. Dietary recommendations aimed at improving microbiota diversity could help support sustained weight loss after surgery.

The BariaGut Taste study aims to compare two dietary approaches following bariatric surgery: nutritional counselling promoting gut microbiota diversity versus standard nutritional counselling. One year after surgery, the study will evaluate differences in microbiota diversity, changes in food preferences and eating behaviours, sensory profiles (taste, smell), levels of digestive and gut hormones fasting, before and after eating, cardiometabolic parameters, mental health, physical activity, and more, to better understand Bariatric surgery is the most effective treatment for long-term weight loss and reducing obesity-related health risks. It alters the gastrointestinal tract as well as metabolic and hormonal functions, influencing eating behaviour. However, weight loss outcomes and long-term maintenance vary between patients, likely due to changes in the gut microbiota. Dietary recommendations aimed at improving microbiota diversity could help support sustained weight loss after surgery.

The BariaGut Taste study aims to compare two dietary approaches following bariatric surgery: nutritional counselling promoting gut microbiota diversity versus standard nutritional counselling. One year after surgery, the study will evaluate differences in microbiota diversity, changes in food preferences and eating behaviours, sensory profiles (taste, smell), levels of digestive and gut hormones fasting, before and after eating, cardiometabolic parameters, mental health, physical activity, and more, to better understand the mechanisms that may explain variations in response to bariatric surgery.

The BariaGut Taste study is a prospective, randomized, controlled trial with two parallel groups, involving non-diabetic patients aged 25 to 65 y undergoing either sleeve gastrectomy or Roux-en-Y gastric bypass. The trial will be conducted at the digestive surgery department of Edouard Herriot Hospital, the endocrinology-diabetes-nutrition department of Lyon Sud Hospital Center, and the Human Nutrition Research Center Rhône-Alpes. 60 participants are expected to be recruited, with 30 in each arm.

Participants will be enrolled before surgery during a routine care visit with the surgeon. They will then undergo a metabolic assessment visit conducted exclusively for research purposes. This visit will allow to collect baseline data on primary outcomes via blood, expired air, and stool samples, anthropometric measurements, indirect calorimetry, a battery of questionnaires (TFEQ-21, DEBQ, PHQ-9, SF36, GSES, PANAS, ESUL, BES, DERS, GAD-7, IPAQ, BAQ, GSRS, sensory alterations, Bristol and Likert scales, and FNS), computerized food preference tests (LFPQ), and a standardized, video-recorded ad libitum buffet.

Participants will be followed up at 3, 6, and 12 months after surgery through visits combining clinical care and research assessments. The dietary interventions specific to each group will be provided since the 3-month visit. The assessments conducted before surgery will be repeated at 6 and 12 months, also integrating clinical care objectives.

Additional blood, stool, and adipose tissue samples collected during surgery will be stored to create a biobank.

02

Conditions studied

  • Obesity (Disorder)
  • Bariatric Surgery

Keywords

  • Bariatric surgery
  • gut microbiota
  • sensory alteration
  • food preferences
  • weight loss maintenance
03

In context

Obesity

6,296 studies on the registry are indexed under Obesity; 1,692 are open to participants now.

This study's planned enrollment of 60 is below the median of 78 across 4,878 interventional studies indexed under Obesity.

Browse Obesity studies →

Lead sponsor

Hospices Civils de Lyon is the lead sponsor of 1,826 studies on the registry; 439 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
25 Years to 65 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Between 25 and 65 years old
  • Undergoing either sleeve gastrectomy or Roux-en-Y gastric bypass
  • With grade 3 obesity (BMI≥40 kg/m²) or with BMI≥35 kg/m² and at least one comorbidity likely to be improved after surgery, with the exception of type 2 diabetes
  • Signed consent form
  • Living less than an hour and 30 minutes from the hospital
  • Presence of effective and stable contraception for women of childbearing potential

Exclusion criteria

Exclusion Criteria:

  • Type 2 diabetes
  • Presence of a contraindication to bariatric surgery
  • Presence of gastrointestinal pathologies with an inflammatory component, known gastroparesis, total gastrectomy, colectomy, exocrine pancreatic insufficiency, known endocrine pathologies inducing hyperglycaemia (uncontrolled dysthyroidism, acromegaly, hypercorticism, etc.), severe chronic renal insufficiency (\< 30mL/min), or hepatocellular insufficiency
  • Claustrophobic
  • Pregnant or breastfeeding women
  • Taking an obesity treatment 3 months before surgery
  • Taking a corticoids, immunosuppression, anabolizing, or growing hormones, antibody treatments less than 3 months before inclusion
  • Daily taking of laxatives or drugs that can strongly interfere with the composition of the intestinal microbiota. If taken sporadically, the patient can be included at a distance (3 weeks) from the laxatives taken.
  • Specific diets (vegetarian, vegan or without gluten)
  • No French speaker
  • Already included in other study
  • Donated blood in the last two months
  • Without freezer access
  • With allergy or intolerance to food propose in ad libitum buffet
05

Study design

Phase
Not applicable
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Single (Participant)
Enrollment
60 participants (estimated)

Study arms

  • Experimental
    Participants with nutritional counselling promoting gut microbiota diversity

    Given the low amounts of food consumed during the first months after surgery, the specific nutritional recommendations for this group will be implemented starting 3 months post-surgery. Before 3 months, participants will receive the standard nutritional recommendations of routine care after bariatric surgery, identical to those given to the second group (see below). From 3 months onwards, participants will be encouraged to increase the consumption of certain specific foods known for their benefits on the gut microbiota, particularly for promoting gut bacterial diversity, in addition to maintaining protein intake and paying attention to food textures. Summary sheets will be provided to help recall the recommendations.

    Other: Nutritional counseling

  • No intervention
    Participants with standard nutritional counselling

    The nutritional recommendations given to participants in this group are those applied in routine care within the Endocrinology, Diabetes, and Nutrition (EDN) Department for patients who have undergone sleeve gastrectomy or gastric bypass (Roux-en-Y). These recommendations aim to maintain adequate protein intake and are adapted to the recent changes in their digestive tract (pureed then mashed food during the first postoperative month). During the first 6 months, patients' food intake is significantly below their nutritional needs. So it is important to pay close attention to hydration (away from meals) and macronutrient intake, especially proteins, as well as the progression of food texture and chewing.

Interventions

  • OtherNutritional counseling

    Nutritional counseling

06

What researchers measure

Primary outcomes

  1. Microbiota diversity 12 months after surgery

    The change in the diversity of the microbiota (shot gun metagenomic analysis, counting the number of microbial genes), between before surgery and one year after surgery (delta) between the two dietary intervention groups.

    Time frame: Primary outcome will be assessed three times : before the surgery, 6 and 12 months after

Secondary outcomes

  1. Eating behaviour during a standardised, filmed and validated ad libitum buffet : Food intake

    energy intake, macro- and micronutrient intake The items chosen during the buffet from the 17 items that will be offered will be noted. The quantities in g and calories consumed of each item will be estimated from the weighing of the plates before and after the buffet, the contribution of each of the items to the energy intake will also be evaluated.

    Time frame: Before the surgery and at 6 and 12 month after

  2. Eating behaviour during a standardised, filmed and validated ad libitum buffet: Nutritional quality

    Nutritional quality through analysis of the foods chosen and consumed Buffet items are classified (pre-defined classification) into seven groups based on their macronutrient content and energy density: starchy foods, meat and fish, fruits and vegetables, dairy products, sweet desserts, sauces, and sweetened beverages. They are also classified according to their fat, sugar, and protein content, and their energy density (4 groups). The quantities consumed in grams and as a percentage of energy intake per group will be assessed for each subject and per visit.

    Time frame: Before the surgery and at 6 and 12 month after

  3. Eating behaviour during a standardised, filmed and validated ad libitum buffet: Meal microstructure

    time spent selecting food at the buffet, duration of ingestion, ingestion speed, total meal duration, number of bites per minute, total number of bites and bites by food type, and food choices Several indicators will be assessed for the buffet's microstructure based on the analysis of videos taken during the buffet: \- Buffet time

    Time frame: Before the surgery and at 6 and 12 month after

  4. Eating behaviour during a standardised, filmed and validated ad libitum buffet: Meal appreciation

    time spent selecting food at the buffet, duration of ingestion, ingestion speed, total meal duration, number of bites per minute, total number of bites and bites by food type, and food choices Assessed with visual analog scale from 1(worse outcome) to 10 (better outcome)

    Time frame: Before the surgery and at 6 and 12 month after

  5. Eating behaviour and preferences : Behaviors

    binge eating using sub-scores from tthe BES (Binge Eating Scale) for binge eating BES : Binge Eating Scale - score from 0 to 46, score of 46 = highest level of binge eating disorder

    Time frame: Before the surgery and at 6 and 12 month after

  6. Eating behaviour and preferences : Food preferences

    Food preferences using the short version of the LFPQ (Leeds Food Preference Questionnaire) LFPQ : Leeds Food and Preference Questionnaire- score from 0 to 100 on preference or motivation for a type of food, high score = strong preference or motivation

    Time frame: Before the surgery and at 6 and 12 month after

  7. Appetite : hunger level

    Assessed using visual analog scales rated from 0 (worse outcome) to 10 (better outcome) on the following dimensions : hunger

    Time frame: Before the surgery and at 6 and 12 month after

  8. Appetite : satiety

    Assessed using visual analog scales rated rom 0 (worse outcome) to 10 (better outcome) on the following dimensions : feeling of satiety

    Time frame: Before the surgery and at 6 and 12 month after

  9. Appetite : desire to eat

    Assessed using visual analog scales rated from 0 (worse outcome) to 10 (better outcome) on the following dimensions : desire to eat

    Time frame: Before the surgery and at 6 and 12 month after

  10. Appetite : prospective consumption

    Assessed using visual analog scales rated from 0 (worse outcome) to 10 (better outcome) on the following dimensions : consommation

    Time frame: Before the surgery and at 6 and 12 month after

  11. Appetite : meal appreciation

    Assessed using visual analog scales rated rom 0 (worse outcome) to 10 (better outcome) on the following dimensions : meal appreciation

    Time frame: Before the surgery and at 6 and 12 month after

  12. Sensory functions : detection scores

    Assessed using Taste Strips tests

    Time frame: Before the surgery and at 6 and 12 month after

  13. Sensory functions : intensity

    Assessed using Taste Strips tests

    Time frame: Before the surgery and at 6 and 12 month after

  14. Sensory functions : pleasantness

    Assessed using Taste Strips tests

    Time frame: Before the surgery and at 6 and 12 month after

  15. Sensory functions : edibility of tastes

    Assessed using Taste Strips tests

    Time frame: Before the surgery and at 6 and 12 month after

  16. Sensory functions : edibility of odors

    Assessed using Taste Strips tests

    Time frame: Before the surgery and at 6 and 12 month after

  17. Self-reported alterations in sensory functions

    Assessed using dedicated questions

    Time frame: Before the surgery and at 6 and 12 month after

  18. Body perception

    Assessed using the BAQ questionnaire (Body Awareness Questionnaire) BAQ : Body Awarness Questionnaire - score from 13 to 65, score of 65 = positive assessment of one's body

    Time frame: Before the surgery and at 6 and 12 month after

  19. Appetite : desire to eat

    Assessed using visual analog scales rated from 0 to 10 on the following dimensions: desire to eat

    Time frame: Before the surgery and at 6 and 12 month after

  20. Appetite : prospective consumption

    Assessed using visual analog scales rated from 0 to 10 on the following dimensions

    Time frame: Before the surgery and at 6 and 12 month after

  21. Microbiota composition

    Evaluated via gene function analysis from metagenomics data, metabolomics and short-chain fatty acid quantification

    Time frame: Before the surgery and at 6 and 12 month after

  22. Microbiota function

    Evaluated via gene function analysis from metagenomics data, metabolomics and short-chain fatty acid quantification

    Time frame: Before the surgery and at 6 and 12 month after

  23. Endocrine, digestive or intestinal hormones

    Blood sample to measure : Adiponectin µg/ml

    Time frame: Before the surgery and at 6 and 12 month after Fasting (all except acylated ghrelin), before the buffet and 1 hour after (adiponectin, total GLP1, ghrelin, acylated ghrelin, total PYY, glucagon, GIP and FGF-19)

  24. Exhaled gas profiles

    Assessed by volatolomic signatures

    Time frame: Before the surgery and at 6 and 12 month after

  25. Cardio-metabolic profile parameters

    BMI will be assessed

    Time frame: Before the surgery and at 6 and 12 month after

  26. Cardio-metabolic profile parameters

    Energy metabolism by indirect calorimetry

    Time frame: Before the surgery and at 6 and 12 month after

  27. Cardio-metabolic profile parameters

    postprandial plasma markers: We will assess: glycaemia (g/L)

    Time frame: Before the surgery and at 6 and 12 month after

  28. Cardio-metabolic profile parameters

    CRP

    Time frame: Before the surgery and at 6 and 12 month after

  29. Vital parameters

    Blood pressure

    Time frame: Before the surgery and at 6 and 12 month after

  30. Nutritional status: Blood vitamin

    Blood vitamin status : For the research, we will focus only whether or not the participant has a deficiency in one of the vitamins measured (yes/no variable). The vitamins assessed are : \- Vitamin B12 (pmol/L) should be above 145 pmol/L

    Time frame: Before the surgery and at 6 (except plasma fatty acid profile) and 12 month after

  31. Nutritional status : Blood mineral

    Blood mineral status: * Calcium (mmol/L) should be above 64 mmol/L * Phosphor (mmol/L) should be above 0.81 mmol/L * Magnesium (mmol/L) should be above 0.66 mmol/L * Sodium (mmol/L) should be above 136 mmol/L * Potassium (mmol/L) should be above 3.4 mmol/L * Chlore (mmol/L) should be above 98 mmol/L

    Time frame: Before the surgery and at 6 (except plasma fatty acid profile) and 12 month after

  32. Nutritional status : Plasma fatty acid

    Plasma fatty acid profile

    Time frame: Before the surgery and at 6 (except plasma fatty acid profile) and 12 month after

  33. Nutritional status : Protein

    Protein status

    Time frame: Before the surgery and at 6 (except plasma fatty acid profile) and 12 month after

  34. Average energy

    Assessed using 3-day dietary recall randomly selected from the 7 days preceding the visits

    Time frame: Before the surgery and at 6 and 12 month after

  35. macronutrients intakes and proportions

    Assessed using 3-day dietary recall randomly selected from the 7 days preceding the visits

    Time frame: Before the surgery and at 6 and 12 month after

  36. micronutrients intakes and proportions

    Assessed using 3-day dietary recall randomly selected from the 7 days preceding the visits

    Time frame: Before the surgery and at 6 and 12 month after

  37. Mental health: Quality of life

    Quality of life using the SF36 questionnaire SF36 - health status questionnaire - score from 0 to 100, score of 100 = excellent perceived health

    Time frame: Before the surgery and at 6 and 12 month after

  38. Mental health: Self-confidence

    Self-confidence and self-efficacy using the GSES GSES: Generalized Self-Efficacy Scale - score of 10 to 40, score of 40 = strong confidence in one's ability to effectively manage different life situations and challenges

    Time frame: Before the surgery and at 6 and 12 month after

  39. Mental health: Depression

    Depression with PHQ-9 PHQ-9: Patient Health Questionnaire -score from 0 to 27, score of 27=severe depression

    Time frame: Before the surgery and at 6 and 12 month after

  40. Mental health: Anxiety

    Anxiety assessment using GAD-7 GAD-7: Generalized Anxiety Disorder - if score \>7 then anxiety disorders should be suspected

    Time frame: Before the surgery and at 6 and 12 month after

  41. Physical activity

    Assessed using the short version of the IPAQ IPAQ: International Physical Activity Questionnaire - continuous daily energy expenditure score, high score means high AP The questionnaire allows the subject to be classified according to 3 levels of activity: inactive, moderate, high.

    Time frame: Before the surgery and at 6 and 12 month after

  42. Emotions: positive and negative

    positive and negative emotion assessed using the PANAS scale PANAS: Positive Affectivity and Negative Affectivity Scale - 2 scores from 10 to 50 - positive affectivity score = 50 best, negative affectivity score = 50 worst

    Time frame: Before the surgery and at 6 and 12 month after

  43. Emotions: food phobias

    food phobias using the FNS questionnaire FNS : Food Neophobia Scale -score from 10 to 70 - score of 70 = neophobia, i.e. less willingness to try new foods

    Time frame: Before the surgery and at 6 and 12 month after

  44. Emotions: loneliness

    loneliness using the ESUL questionnaire University of Laval Loneliness Scale - score from 20 to 80, score of 80 = most pronounced feeling of loneliness

    Time frame: Before the surgery and at 6 and 12 month after

  45. Changes in stool consistency

    Assessed using Bristol stool scale Bristol scale : 7 types of stools to choose from photo: type 1 = hard and lumpy stools, type 7 = completely liquid stools

    Time frame: Before the surgery and at 6 and 12 month after

  46. Changes in stool frequency

    Assessed using Bristol stool scale : 7 types of stools to choose from photo: type 1 = hard and lumpy stools, type 7 = completely liquid stools

    Time frame: Before the surgery and at 6 and 12 month after

  47. Changes in gastrointestinal symptoms

    Assessed using Bristol stool scale

    Time frame: Before the surgery and at 6 and 12 month after

  48. Grade of hepatic steatosis

    Evaluation by FibroScan® but only for patients who had a FibroScan® performed before surgery.

    Time frame: Before the surgery and at 12 month after

  49. Grade of hepatic fibrosis

    Evaluation by FibroScan® but only for patients who had a FibroScan® performed before surgery.

    Time frame: Before the surgery and at 12 month after

  50. Eating behaviour and preferences : Behaviors

    Behaviors (emotional eating and cognitive restraint) using score from the DEBQ (Dutch Eating Behavior Questionnaire) a DEBQ : Dutch Eating Behaviour Questionnaire : 3 sub-scores: cognitive restriction, reactivity to external stimuli and emotionality from 1 to 5, score 5 = strong impact of eating behavior

    Time frame: Before the surgery and at 6 and 12 month after

  51. Hepatic metabolic flexibility

    Assessed via the degree of alteration of MAMs (Mitochondia-Associated Membranes) in peripheral blood mononuclear cells (PBMCs), only for patients who had a FibroScan® performed before surgery.

    Time frame: Before the surgery and at 6 and 12 month after

  52. Safety parameters

    thyroid function: Thyroid function is assessed based on TSH levels in mIU/L (should be above 0.4 mIU/L and below 4.8 mIU/L), 2. The assessment for the research is whether the measures are within the limits or not (yes/no variable).

    Time frame: Before the surgery and at 6 and 12 month after

  53. Compliance and follow-up of advice given during the intervention

    Based on the three 24-hour reminders completed by participants before each visit, the dietitian will classify participants into three categories: good, average or poor compliance.

    Time frame: until month 12

  54. Eating behaviour during a standardised, filmed and validated ad libitum buffet: Meal microstructure

    time spent selecting food at the buffet

    Time frame: Before the surgery and at 6 and 12 month after

  55. Eating behaviour during a standardised, filmed and validated ad libitum buffet: Meal microstructure

    duration of ingestion

    Time frame: Before the surgery and at 6 and 12 month after

  56. Eating behaviour during a standardised, filmed and validated ad libitum buffet: Meal microstructure

    ingestion speed

    Time frame: Before the surgery and at 6 and 12 month after

  57. Changes in stool consistency

    Assessed using Likert scale Likert scale : 7 types of stools to choose from photo: type 1 = hard and lumpy stools, type 7 = completely liquid stools

    Time frame: Before the surgery and at 6 and 12 month after

  58. Changes in stool consistency

    Assessed using gastrointestinal symptoms using GSRS Gastrointestinal Symptom Questionnaire - score 15 to 105, score 105=severe gastrointestinal symptoms

    Time frame: Before the surgery and at 6 and 12 month after

  59. Safety parameters

    complete blood count

    Time frame: Before the surgery and at 6 and 12 month after

  60. Safety parameters

    AST

    Time frame: Before the surgery and at 6 and 12 month after

  61. Safety parameters

    ALT

    Time frame: Before the surgery and at 6 and 12 month after

  62. Safety parameters

    gamma GT

    Time frame: Before the surgery and at 6 and 12 month after

  63. Safety parameters

    bilirubin

    Time frame: Before the surgery and at 6 and 12 month after

  64. Safety parameters

    alkaline phosphate

    Time frame: Before the surgery and at 6 and 12 month after

  65. Safety parameters

    creatinine

    Time frame: Before the surgery and at 6 and 12 month after

  66. Safety parameters

    uric acid

    Time frame: Before the surgery and at 6 and 12 month after

  67. Safety parameters

    ionogram results: Sodium (mmol/L) which should be between 136 and 145 Potassium (mmol/L) which should be between 3.4 and 4.5 Chlorine (mmol/L) which should be between 98 and 107 Bicarbonates (mmol/L) which should be between 22 and 29

    Time frame: Before the surgery and at 6 and 12 month after

  68. Safety parameters

    coagulation : prothrombin time

    Time frame: Before the surgery and at 6 and 12 month after

  69. Changes in stool frequency

    Assessed using Likert scale

    Time frame: Before the surgery and at 6 and 12 month after

  70. Changes in stool frequency

    Assessed using gastrointestinal symptoms using GSRS : 15 questions with answers from No discomfort at all at Very severe discomfort (7 levels)

    Time frame: Before the surgery and at 6 and 12 month after

  71. Changes in gastrointestinal symptoms

    Assessed using Likert scale

    Time frame: Before the surgery and at 6 and 12 month after

  72. Changes in gastrointestinal symptoms

    gastrointestinal symptoms using GSRS

    Time frame: Before the surgery and at 6 and 12 month after

  73. Eating behaviour during a standardised, filmed and validated ad libitum buffet: Meal microstructure

    total meal duration

    Time frame: Before the surgery and at 6 and 12 month after

  74. Eating behaviour during a standardised, filmed and validated ad libitum buffet: Meal microstructure

    number of bites per minute

    Time frame: Before the surgery and at 6 and 12 month after

  75. Eating behaviour during a standardised, filmed and validated ad libitum buffet: Meal microstructure

    total number of bites

    Time frame: Before the surgery and at 6 and 12 month after

  76. Eating behaviour during a standardised, filmed and validated ad libitum buffet: Meal microstructure

    bites by food type

    Time frame: Before the surgery and at 6 and 12 month after

  77. Eating behaviour during a standardised, filmed and validated ad libitum buffet: Meal microstructure

    food choices

    Time frame: Before the surgery and at 6 and 12 month after

  78. Eating behaviour during a standardised, filmed and validated ad libitum buffet: Meal microstructure

    Calorie intake consumed per minute of the buffet

    Time frame: Before the surgery and at 6 and 12 month after

  79. Safety parameters

    ionogram results: Anion gap = (Na+ + K+) - (HCO3- + Cl-) (mmol/L) which should be between 12 and 20

    Time frame: Before the surgery and at 6 and 12 month after

  80. Endocrine, digestive or intestinal hormones

    Blood sample to measure : Ghrelin pg/ml acylated ghrelin pg/ml

    Time frame: Before the surgery and at 6 and 12 month after Fasting (all except acylated ghrelin), before the buffet and 1 hour after (adiponectin, total GLP1, ghrelin, acylated ghrelin, total PYY, glucagon, GIP and FGF-19)

  81. Endocrine, digestive or intestinal hormones

    Blood sample to measure : GIP pmol/l total GLP-1 : pmol/L glucagon : pmol/L

    Time frame: Before the surgery and at 6 and 12 month after Fasting (all except acylated ghrelin), before the buffet and 1 hour after (adiponectin, total GLP1, ghrelin, acylated ghrelin, total PYY, glucagon, GIP and FGF-19)

  82. Endocrine, digestive or intestinal hormones

    Blood sample to measure : total PYY : ng/L

    Time frame: Before the surgery and at 6 and 12 month after Fasting (all except acylated ghrelin), before the buffet and 1 hour after (adiponectin, total GLP1, ghrelin, acylated ghrelin, total PYY, glucagon, GIP and FGF-19)

  83. Endocrine, digestive or intestinal hormones

    Blood sample to measure : leptin : ng/ml

    Time frame: Before the surgery and at 6 and 12 month after Fasting (all except acylated ghrelin), before the buffet and 1 hour after (adiponectin, total GLP1, ghrelin, acylated ghrelin, total PYY, glucagon, GIP and FGF-19)

  84. Cardio-metabolic profile parameters

    We will assess: insulin (mU/L)

    Time frame: Before the surgery and at 6 and 12 month after

  85. Cardio-metabolic profile parameters

    We will assess: triglycerides (mmol/L), HDL (mmol/L), LDL (mmol/L), ApoB (mmol/L), sphingolipid (mmol/L) and unesterified fatty acid(mmol/L)

    Time frame: Before the surgery and at 6 and 12 month after

  86. Cardio-metabolic profile parameters

    we will calculate: HOMA-IR (=insulin\*glycarmia/22.5) and the total cholesterol/HDL cholesterol ratio.

    Time frame: Before the surgery and at 6 and 12 month after

  87. Cardio-metabolic profile parameters

    postprandial plasma markers: We will assess: insulin (mU/L)

    Time frame: Before the surgery and at 6 and 12 month after

  88. Nutritional status: Blood vitamin

    Blood vitamin status : For the research, we will focus only whether or not the participant has a deficiency in one of the vitamins measured (yes/no variable). The vitamins assessed are : \- Vitamin B9 (mmol/L) should be above 10.4 mmol/L

    Time frame: Before the surgery and at 6 (except plasma fatty acid profile) and 12 month after

  89. Nutritional status: Blood vitamin

    Blood vitamin status : For the research, we will focus only whether or not the participant has a deficiency in one of the vitamins measured (yes/no variable). The vitamins assessed are : \- Vitamin B1 (nmol/L) should be above 78 nmol/L

    Time frame: Before the surgery and at 6 (except plasma fatty acid profile) and 12 month after

  90. Nutritional status: Blood vitamin

    Blood vitamin status : For the research, we will focus only whether or not the participant has a deficiency in one of the vitamins measured (yes/no variable). The vitamins assessed are : * Vitamin C (µmol/L) should be above 25 µmol/L * Vitamin A (µmol/L) should be above 1.40 µmol/L

    Time frame: Before the surgery and at 6 (except plasma fatty acid profile) and 12 month after

  91. Nutritional status : Blood mineral

    Blood mineral status: * Iron (µmol/L) should be above 5.8µmol/L * Selenium (µmol/L) should be above 56µmol/L * Zinc (µmol/L) should be above 9.20µmol/L

    Time frame: Before the surgery and at 6 (except plasma fatty acid profile) and 12 month after

  92. Safety parameters

    thyroid function: Thyroid function is assessed based on free thyroxine in pmol/L (should be above 11.9 pmol/L and below 21.9 pmol/L) The assessment for the research is whether the measures are within the limits or not (yes/no variable).

    Time frame: Before the surgery and at 6 and 12 month after

  93. Safety parameters

    thyroid function: Thyroid function is assessed based on free triiodothyronine in pmol/L (should be above 3.1 pmol/L and below 6.8 pmol/L). The assessment for the research is whether the three measures are within the limits or not (yes/no variable).

    Time frame: Before the surgery and at 6 and 12 month after

  94. Cardio-metabolic profile parameters

    Waist-to-hip ratio will be assessed

    Time frame: Before the surgery and at 6 and 12 month after

  95. Vital parameters

    resting heart rate

    Time frame: Before the surgery and at 6 and 12 month after

  96. Safety parameters

    coagulation : activated partial thromboplastin time

    Time frame: Before the surgery and at 6 and 12 month after

  97. Safety parameters

    coagulation : fibrinogen

    Time frame: Before the surgery and at 6 and 12 month after

  98. Cardio-metabolic profile parameters

    We will assess: total cholesterol (g/L)

    Time frame: Before the surgery and at 6 and 12 month after

  99. Cardio-metabolic profile parameters

    We will assess: HbA1c (mmol/mol),

    Time frame: Before the surgery and at 6 and 12 month after

07

Study locations

1 of 3 sites recruiting
  • Hospital Edouard Herriot, digestive surgery department
    Lyon, 69310, France
    Recruiting
  • Centre de recherche en nutrition humaine de Rhône-Alpes
    Pierre-Bénite, 69310, France
    Not yet recruiting
  • Hôpital Lyon sud, Endocrinology Diabetes Nutrition department
    Pierre-Bénite, 69310, France
    Not yet recruiting
08

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Apr 3, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT07268508
Lead sponsor
Hospices Civils de Lyon
Responsible party
Sponsor
First posted
Dec 5, 2025
Start date
Nov 5, 2025
Primary completion
Nov 5, 2027 (estimated)
Completion
Apr 5, 2029 (estimated)
Last update
Apr 3, 2026

Study contacts

Julie-Anne NAZARE
Contact
julie-anne.nazare@univ-lyon1.fr
+33 6 88 87 09 62
Berenice SEGRESTIN
Contact

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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