Effect of a Low-carb Dietary Intervention in Obese Patients: a Pilot Trial

Study Overview
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Brief Summary
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Effects of a 6 months low-carb dietary intervention on glycemic control, body composition and gut-brain interaction in obese and lean patients with and without glucose intolerance or diabetes

Official Title
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Understanding Gut-brain Interactions and the Effect of a Low-carb Dietary Intervention in Obese Patients With and Without Glucose Intolerance or Diabetes: a Pilot Trial

Conditions
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Glucose Intolerance, Obesity

Intervention / Treatment
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* Other: Low Carb diet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Group A: HEALTHY LEAN CONTROLS Healthy normal weight subjects with a body-mass index of 19.0-24.9kg/m2, HbA1C <5.7% and fasting glucose <5.6 mmol/l Normal eating habits Stable body weight for at least three months Informed Consent as documented by signature Group B: PRE-DIABETIC or DIABETIC OBESE Pre-diabetic/Diabetic obese with a HbA1C >5.7% and/or fasting glucose >5.6 mmol/l) and body-mass index > 30kg/m2, otherwise healthy Normal eating habits Stable body weight for at least three months Informed Consent as documented by signature Exclusion Criteria: Group A: HEALTHY LEAN CONTROLS Pre-existing low carb diet (less than 45% of daily energy intake by carbohydrates) Pre-existing diet (vegetarian, vegan, gluten-free etc.) Psychiatric illness Alcohol abuse, (smoking allowed) Regular intake of medications, (oral contraceptives allowed) Intake of antibiotics within the last 3 months before inclusion Regular intake of pro- or prebiotics Chronic diseases of the gastrointestinal tract, history of gastrointestinal surgery with major changes to the gastrointestinal tract (e.g. bariatric surgery) Clinically relevant acute or chronic inflammatory disease Pregnancy Participation in another study with investigational drug within the 30 days preceding and during the present study. Group B: PRE-DIABETIC or DIABETIC OBESE Pre-existing low carb diet (less than 45% of daily energy intake by carbohydrates) Pre-existing diet (vegetarian, vegan, gluten-free etc.) Psychiatric illness Alcohol abuse, (smoking allowed) Regular intake of medications (except: oral contraceptives, metformin, SGLT-2, statins, and antihypertensive, which are allowed) Intake of antibiotics within the last 3 months before inclusion Regular intake of pro- or prebiotics Chronic diseases of the gastrointestinal tract, history of gastrointestinal surgery with major changes to the gastrointestinal tract (e.g. bariatric surgery) Clinically relevant acute or chronic inflammatory disease Pregnancy Participation in another study with investigational drug within the 30 days preceding and during the present study.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Low Carb dietary Intervention<br> | Other: Low Carb diet<br>* Low Carb diet (max. 130g carbohydrates/d) for 6 months<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effect of a low-carb dietary intervention on glycemic control as defined by blood glucose level at 2h after an oral glucose tolerance test. |  | Change from baseline to 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effect of a low-carb dietary intervention on body composition as measured with dual-energy x-ray absorptiometry |  | Change from baseline to 6 months | 
| Effect of a low-carb dietary intervention on metabolomics as measured in plasma, urine and stool samples | Metabolomic analysis of the bacterial metabolites present in the urine by combining nuclear magnetic resonance (1H-NMR) and mass spectrometry | Change from baseline to 6 months | 
| Effect of a low-carb dietary intervention on gut microbiota composition as measured in stool samples | Human gut microbiota composition measured with metagenomic shotgun sequencing | Change from baseline to 6 months | 
| Effect of a low-carb dietary Intervention on brain network activity as measured with functional MRI |  | Change from baseline to 6 months | 
| Effect of a low-carb dietary intervention on liver fat fraction as measured with MRI |  | Change from baseline to 6 months |