How Altered Gut-Brain-Axis Influences Food Choices: Part 1

NCT04813003 | Completed

• 1 other identifier: BrainFood Part 1
• Study Type: observational
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

Obesity is currently one of the most substantial health burdens. Due to the production of marked and sustained weight loss, bariatric surgery is an increasingly used therapeutic modality to combat obesity and its comorbidities. Surgical rearrangement of the gastrointestinal tract remarkably alters metabolism and hormones acting on neurological and hypothalamic signalling involved in food decision-making and eating behaviour. In this context, many patients who underwent bariatric surgery self-report changes in appetite, satiety and food preferences. Furthermore, new gut hormone-based (e.g. GLP1-receptor agonist or GLP-1-RA) pharmacotherapies which mimic the effect of bariatric surgery show impressive efficacy on weight reduction by modulation of food behaviour. However, the mechanisms of such functional changes, and how they relate to food decision-making remain unknown. In this project, the investigators propose a novel approach to unravel the effect of obesity treatments (surgical and non-surgical) on the neural coding of nutritional attributes and its impact on dietary choices using a combination of brain imaging, computational modelling of food behaviour and assessment of eating and food purchase behaviour in daily life.

Conditions

Obesity; Food Preferences

Keywords

Obesity; Bariatric Surgery; Food Preferences; Food Behaviour; Computational Modelling; Functional Brain Imaging

Outcome Measures

Primary Outcomes (2)

• Representational similarity analysis to assess neural encoding of food attributes

  Representational similarity analysis is used to analyse the correlation between a voxel-wise representational dissimilarity matrix and a behavioural representational dissimilarity matrix. The correlation of the activity of each voxel for each pair of food items is used to define the voxel-wise representational dissimilarity matrix. Similarly, the correlation of the subjective ratings for each pair of food items is used to define the behavioural representational dissimilarity matrix. The correlation between the voxel-wise representational dissimilarity matrix and the behavioural representational dissimilarity matrix is then assessed to determine if the voxels are encoding the food attributes.

  Continuously while participants perform the tasks (during 2.5 hours)

• Nutrient factor weights

  The nutrient factor weights are estimated using a linear regression with the subjective value ratings as dependent variable and nutrient factors ratings as independent variables and using a logistic regression with the choice as a dependent variable and the nutrient factor ratings as independent variables.

  Continuously while participants perform the tasks (during 2.5 hours)

Secondary Outcomes (1)

• Differences in activity in neural areas involved in self-control and valuation (Dorsolateral prefrontal cortex (dlPFC), ventromedial prefrontal cortex (vmPFC), orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), insula, hippocampus)

  Continuously while participants perform the tasks (during 2.5 hours)

Study Arms (2)

Obesity group (group 1)

Pilot phase: 5 adults with class II-III obesity (BMI≥35kg/m2) planned for bariatric surgery will undergo functional imaging and neurobehavioural tasks before bariatric surgery. Refined protocol phase: 20 overweight adults (BMI≥30kg/m2 or BMI≥28kg/m2 with adiposity-related comorbidities (prediabetes, type 2 diabetes mellitus, hypertension, dyslipidemia)), referred for obesity treatment (surgical or non-surgical).

Other: Functional Brain Imaging and neurobehavioural tasks

Control group (group 2)

Pilot phase: 5 healthy adults with normal body mass (BMI 18.5-24.9kg/m2) matched for age-, sex- and education will serve as a control group and undergo the same experiment. Refined protocol: 20 healthy adults with normal body mass (BMI 18.5-24.9kg/m2) matched for age and sex will serve as a control group and undergo the same experiment.

Other: Functional Brain Imaging and neurobehavioural tasks

Interventions

Functional Brain Imaging and neurobehavioural tasks OTHER

Combination of 3 neurobehavioural tasks: Task 1 consists in subjective value rating of 64 food items. Participants are asked to rate how much they would want to eat the presented food item while fMRI (functional magnetic resonance imaging ) scanning is performed. Task 2 consists in rating of subjective nutrient factor of the same 64 food items. Participants will answer the following four categorical questions in randomized order for each item: low or high in added sugar/protein/fat and healthy or unhealthy. Task 3 consists of a decision-making task. Participants will be presented with two food items (out of the 64 food items), and asked to choose which of the two items they prefer to consume at the end of the experiment.

Control group (group 2); Obesity group (group 1)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Pilot protocol: 5 obese adults planned for bariatric surgery (Group 1) will be recruited by referral from our outpatient endocrine clinic and collaborating Centres of Excellence for Metabolic Surgery. 5 lean healthy adults (Group 2) matched for age-, sex- and education will serve as a control group and will be recruited through advertisement according to guidelines from swissethics. Refined protocol: 20 obese adults planned for obesity treatment (Group 1) will be recruited by referral from our outpatient endocrine clinic and collaborating Centres of Excellence for Metabolic Surgery. 20 lean healthy adults (Group 2) matched for age and sex will serve as a control group and will be recruited through advertisement according to guidelines from swissethics.

You may qualify if:

• Female and male subjects aged 18 years or older
• Proficient German language skills (including written)
• Class II-III obesity (BMI≥35kg/m2)
• Planned for bariatric surgery (Roux-en-Y gastric bypass)
• BMI≥30kg/m2 or BMI≥28kg/m2 with adiposity-related comorbidities (prediabetes, type 2 diabetes mellitus, hypertension, dyslipidemia)
• Referred for obesity treatment (surgical or non-surgical)
• Normal body weight (BMI 18.5-24.9kg/m2)
• Absence of evidence of any active or chronic disease as judged by the Clinical Investigator

You may not qualify if:

• Incapacity to give informed consent
• Previous or current neurological or severe psychiatric illness
• Current or planned pregnancy or breastfeeding
• Claustrophobia
• MRI-contraindications (pacemaker/defibrillator, neurostimulator, drug pump, cochlear implant, heart valve/vascular clips, shunt valve)
• Pilot protocol only: Diabetes according to WHO (World Health Organization ) definition (Fasting plasma glucose ≥7.0mmol/l, random plasma glucose ≥11.1mmol/l, HbA1c ≥6.5%)

Sponsors & Collaborators

• Lia Bally: lead
• ETH Zurich: collaborator

Study Sites (1)

Department of Diabetes, Endocrinology, Clinical Nutrition and Metabolism, Inselspital, Bern University Hospital

Bern, 3010, Switzerland

Location

MeSH Terms

Conditions

Obesity; Food Preferences

Interventions

Functional Neuroimaging

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Feeding Behavior; Behavior

Intervention Hierarchy (Ancestors)

Neuroimaging; Diagnostic Imaging; Diagnostic Techniques and Procedures; Diagnosis; Diagnostic Techniques, Neurological; Investigative Techniques

Study Officials

• Lia Bally, MD, PhD

  University Hospital Bern & University of Bern

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: January 18, 2021
• First Posted: March 24, 2021
• Study Start: April 12, 2021
• Primary Completion: September 5, 2022
• Study Completion: September 5, 2022
• Last Updated: September 23, 2022

Record last verified: 2022-09

Locations

CH (1)