Clinical trial NCT01719913: The Effect of Gluten on Gut Microbiome and Metabolic Health.
Official title: Gut, Grain and Greens (3G): The Effect of Gluten on Gut Microbiome and Metabolic Health.
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Metabolic Diseases
Injury of Gastrointestinal Tract
Lead sponsor: University of Copenhagen
Sponsor class: OTHER
Collaborators: name: Technical University of Denmark
First posted: 2012-11-01
Enrollment: 60
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER

Brief summary: Objective: To identify how specific changes of the gluten content in the diet affect the host-gut microbiome interactions with implications for metabolic health.

Design: A randomized, controlled, single-blinded, cross-over intervention trial consisting of two 8-week interventions periods, separated by a 6-week wash-out period. A total number of 60 participants will be included.

Intervention: low vs high gluten intake.

Detailed description: The study is designed as a randomized, controlled, single-blinded, cross-over intervention trial consisting of two 8-week interventions periods, separated by a 6-week wash-out period. A total number of 60 participants will be included. Participants consume, in randomized order, a gluten-poor diet (\<5 g/d) in the active treatment period and a gluten-rich diet (\>25 g/d) during the control period.

Measurements: Altered quantitative metagenomics at bacterial gene- and species levels is the primary outcome of this study. Secondary outcomes include metabolic and inflammatory markers, circulating appetite hormone levels,serum metabolomics, gastrointestinal transit time and intestinal permeability. Furthermore, selected control measures are included; 4-day food records and a study intervention dietary records.

Eligibility criteria: Inclusion Criteria, compulsory:

* Body mass index (BMI): 25 - 35 kg/m2 OR
* Abdominal obesity: waist circumference: men: ≥ 94cm; women: ≥ 80cm
* No medically prescribed diet
* Weight stable
* Intense sporting activities less than 10 h/week
* Alcohol consumption less than 14 units/week (female) and 21 units/week (male)
* Signed informed consent

Inclusion criteria, minimum one of the following:

* Fasting plasma glucose from 6.1 mmol/l to 6.9 mmol/l
* Reduced high density lipoprotein (HDL) cholesterol; HDL ≤ 1.03 mmol/L for men and ≤ 1.29 mmol/L for women
* Increased triglyceride (TG) \> 1.3 mmol/L
* Systolic blood pressure \> 130 mmHg

Exclusion Criteria:

* Pharmacological treatment; diabetes and blood lipid regulation
* Lactating (or lactating, 6 weeks ago), pregnant (or pregnant, 3 months ago) or wish to become pregnant during the study
* Participation in another biomedical trial 1 month prior to study start
* Diagnosed with any form of diabetes, celiac disease or chronic pancreatitis
* Reported chronic gastrointestinal disorders
* Antibiotic treatment for 3 month prior to study start
* Blood hemoglobin \< 7.0 mmol/l
* Blood donation within 1 month prior to study start

Primary outcomes:
measure: Altered quantitative metagenomics at bacterial gene- and species levels.
timeFrame: Up to 3 years.
Secondary outcomes:
measure: Mean intestinal transit time
timeFrame: Up to 2 years.
measure: Gastrointestinal permeability.
timeFrame: Up to 2 years.
measure: Colonic fermentation
timeFrame: Up to 2 years.
measure: Blood pressure and pulse.
timeFrame: Up to 1 year.
measure: Saliva microbial flora
timeFrame: Up to 2 years.
measure: Nasal fluid
timeFrame: Up to 3 years.
measure: Appetite hormones
timeFrame: Up to 3 years.
measure: Celiac disease markers
timeFrame: Up to 1 year.
measure: Blood lipid profile
timeFrame: Up to 2 years.
measure: Bioimpedance
timeFrame: Up to 1 year.
measure: Breath hydrogen.
timeFrame: Up to 2 years.
measure: Insulin
timeFrame: Up to 2 years.
measure: Glucose
timeFrame: Up to 2 years.
measure: C-peptide
timeFrame: Up to 2 years.
measure: Inflammatory makers
timeFrame: Up to 3 years.
measure: Anthropometric characteristics.
timeFrame: Up to 1 year.
Other outcomes:
measure: 4 days precoded food diary.
timeFrame: Up to 2 years.
measure: Gastrointestinal symptoms.
timeFrame: Up to 2 years.
Locations:
city: Copenhagen
country: Denmark
facility: The Novo Nordisk Foundation of Basic Metabolic Health, Section for Metabolic Genetics
Study officials:
affiliation: University of Copenhagen
name: Oluf B Pedersen, MD, DMSCi,Professor
role: PRINCIPAL_INVESTIGATOR
References:
citation: Lind MV, Lauritzen L, Vestergaard H, Hansen T, Pedersen O, Kristensen M, Ross AB. One-carbon metabolism markers are associated with cardiometabolic risk factors. Nutr Metab Cardiovasc Dis. 2018 Apr;28(4):402-410. doi: 10.1016/j.numecd.2018.01.005. Epub 2018 Jan 31.