CompletedNCT06787001GUTBBBUpdated Feb 18, 2026

Understanding How Gut and Brain Barriers Are Linked to Inflammation in Obesity

An observational study in Obesity (Disorder), Systemic Inflammation Markers and Intestinal Barrier Dysfunction, sponsored by University Hospital, Gentofte, Copenhagen. Completed at 1 site in Denmark. Open to participants aged 40 Years to 70 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-02-18.

Sponsored by University Hospital, Gentofte, Copenhagen · Observational

Study type: Observational
Model: Case-control
Time perspective: Cross-sectional
Enrollment: 50
Ages: 40 Years to 70 Years
Sex: All

Study summary

The goal of this observational study is to understand how obesity affects the function of the gut and blood-brain barriers in adults. These barriers protect the body and brain from harmful substances, and changes in their function may lead to inflammation and increased risk of chronic diseases. The study will include 25 participants with obesity (BMI over 35) and 25 healthy participants (BMI 20-25) matched by age and gender.

The main questions it aims to answer are:

How does obesity affect the blood-brain barrier and its connection to cognitive and psychopathological status?
Does increased gut permeability lead to higher inflammation levels?
Does obesity increase the permeability of the gut barrier?

Researchers will compare results from participants with obesity to healthy participants to determine how obesity impacts barrier function, inflammation, and overall health.

Participants will:

Attend three visits over several days, including:

Screening visit: A health examination with weight, height, blood pressure, blood tests, and a scan to assess body fat distribution.
Visit 1: Provide a stool sample, drink a sugar solution to assess gut permeability, collect urine samples, and take cognitive as well as psychopathological tests.
Visit 2: Undergo an MRI scan to assess the blood-brain barrier and its function.

The study aims to identify how obesity-related changes in these barriers contribute to health risks.

Read the detailed description

The study is a cross-sectional study including individuals with obesity and lean healthy controls. It is planned to recruit 25 individuals with a BMI above 35 kg/m2 and 25 lean healthy gender- and age-matched individuals with a BMI between 20-25 kg/m2. Given the extensive nature of these examinations, which include the lactulose/sucralose-mannitol test, DCE-MRI, metabolic and cognitive assessments, they will be conducted on three separate study days, in random order, and with fixed time intervals between each study day. The study employs a comprehensive approach to assess gut barrier integrity using the lactulose/sucralose-mannitol test to evaluate barrier permeability and absorptive surface area, complemented by measuring biomarkers related to gut integrity and microbial-immune interaction. Additionally, the study analyses circulating proinflammatory biomarkers and microbial genetic material to understand systemic inflammation and bacterial translocation in obesity. The integrity of the BBB is examined using DCE-MRI to detect alterations in obesity and investigate correlation between BBB permeability and obesity-related neurological conditions. Cognitive functions are assessed through tests that evaluate domains like processing speed and memory and psychopathological tests will evaluate depressive and anxiety symptoms. These tests explore the potential impact of obesity on the central nervous system. Metabolic and physiological measurements, including glucose levels, haemoglobin A1c, and body composition, provide insights into the metabolic effects of obesity and its broader physiological implications.

Conditions studied

Obesity (Disorder)
Systemic Inflammation Markers
Intestinal Barrier Dysfunction
Blood Brain Barrier
Neurodegenerative Disease

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Keywords

intestinal barrier function
blood brain barrier function
microbiome
systemic inflammation
bacterial translocation

In context

Obesity

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

This study's enrollment of 50 is below the median of 135 across 1,283 observational studies indexed under Obesity.

Browse Obesity studies →

Lead sponsor

University Hospital, Gentofte, Copenhagen is the lead sponsor of 154 studies on the registry; 9 are open to participants now.

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

Who can participate

Ages eligible: 40 Years to 70 Years
Sexes eligible: All
Accepts healthy volunteers: Yes
Sampling method: Non-probability sample

Study population

Older individuals with and without obesity

Inclusion criteria for individuals living with obesity

BMI > 35 kg/m2, bioimpedance-assessed body fat > 30% (men) or > 40% (women), and hip/waist-ratio > 0.85
Age ≥40 and ≦70 years
Sterilised or postmenopausal women (> 12 months amenorrhoea or females ≥ 60 years of age) or women who are sexually abstinent during the entire study period or are practicing non-hormonal contraception (no contraceptive pill, no hormonal intrauterine device) during the entire study period
Able to understand written participant information and give signed informed consent.

Inclusion criteria

Inclusion criteria for lean healthy controls

BMI 20-25 kg/m2, bioimpedance-assessed body fat \< 30% (men) or \< 40% (women), and hip/waist-ratio \< 0.85
Age ≥40 and ≦70 years
Sterilised or postmenopausal women (> 12 months amenorrhoea or females ≥ 60 years of age) or women who are sexually abstinent during the entire study period or are practicing non-hormonal contraception (no contraceptive pill, no hormonal intrauterine device) during the entire study period

Exclusion criteria

Exclusion Criteria:

Diagnosis of diabetes mellitus type 1 or type 2.
Inflammatory gastrointestinal conditions such as Crohn's disease, ulcerative colitis, clinically significant food allergies, candidiasis, etc.
Previous bariatric surgery, or surgeries involving the removal of intestinal tissue
The use of weight loss-inducing medication such as GLP-1 receptor agonists, bupropion/naltrexone, and orlistat within 90 days prior to screening
Planned elective surgery during the study period with the exception of dermatosurgical, ENT (ear, nose, throat) or dental procedures not requiring general anaesthesia and/or perioperative antibiotic treatment
Chronic systemic inflammatory diseases (e.g. rheumatoid arthritis) and other conditions significantly affecting inflammation status or immunoregulation (severe allergies, status post transplantation etc.)
History of sleep disorders
Chronic infectious diseases such as hepatitis, HIV etc.
Use of proton pump inhibitors, metformin, anti-biotic, lipid-lowering statins, laxatives, antihistamines, paracetamol, aspirin, statins, tricyclic antidepressants, selective serotonin reuptake inhibitor antidepressants and any other medications correlated to changes in faecal microbiome diversity for the period of the study and within 20 days prior to screening
Active use of nicotine products, including but not limited to cigarettes, vapes, or any other form of nicotine consumption.
Abuse of alcohol and/or drugs, or any other co-existing conditions that will make the individual unsuitable to participate in the study, as deemed by the investigators
Pregnancy or desire to become pregnant during the study period
Breastfeeding
Any concomitant disease or treatment that, at the discretion of the investigators, might jeopardise the participant's safety during the study
Mental incapacity or language barriers that preclude adequate understanding or cooperation, or unwillingness to comply with study requirements
Body weight above the MRI scanner's maximum capacity of 140 kg or claustrophobia at a level, which makes MRI scans impossible
Severe kidney disease with increased serum creatinine and low estimated glomerular filtration rate (GFR) (\<60ml/min/1.73m2)
Magnetic foreign objects in the body (e.g. pacemaker, metal implants from operation, etc.)
Adherence to a restrictive diet (e.g. ketogenic diet, vegan diet, raw diet, low FODMAP diet, and paleo diet) which is significantly correlated to changes in faecal microbiome diversity 7.2.3. Criteria for discontinuation in the study
Withdrawal of informed consent
Pregnancy
Any safety consideration as assessed by the investigators
Any exclusion criterion developing or being diagnosed during the course of the study
Non-compliance with the study protocol as deemed by the investigators

Study design

Observational model: Case-control
Time perspective: Cross-sectional
Enrollment: 50 participants (actual)
Patient registry: No
Biospecimen retention: Samples without dna

Groups and cohorts

Individuals living with obesity
BMI \> 35 kg/m2, bioimpedance-assessed body fat \> 30% (men) or \> 40% (women), and hip/waist-ratio \> 0.85
Individuals with lean bodies
BMI 20-25 kg/m2, bioimpedance-assessed body fat \< 30% (men) or \< 40% (women), and hip/waist-ratio \< 0.85

What researchers measure

Primary outcomes

BBB permeability
Differences in BBB permeability using Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) between individuals with and without obesity
Time frame: 25 minutes post contrast administration

Secondary outcomes

Correlation between BBB permeability and gut barrier permeability
Ki values from DCE-MRI and Lactulose/Mannitol ratio from Lactulose/Sucralose-Mannitol test.
Time frame: 25 minutes post contrast administration and 0-5h Lactulose/Mannitol ratio
Correlation between BBB permeability and gut barrier permeability
Ki values from DCE-MRI and Lactulose/Mannitol ratio from Lactulose/Sucralose-Mannitol test.
Time frame: 25 minutes post contrast administration and 5-24h Lactulose/Mannitol ratio
Correlation between BBB permeability and gut barrier permeability
Ki values from DCE-MRI and quantities of plasma Zonulin
Time frame: 25 minutes post contrast administration and baseline (fasting) Zonulin
Correlation between BBB permeability and gut barrier permeability
Ki values from DCE-MRI and quantities of plasma Citrulline
Time frame: 25 minutes post contrast administration and baseline (fasting) Citrulline
Correlation between BBB permeability and gut barrier permeability
Ki values from DCE-MRI and quantities of plasma Regenerating islet-derived protein 3-alpha
Time frame: 25 minutes post contrast administration and baseline (fasting) Regenerating islet-derived protein 3-alpha
Correlation between BBB permeability and gut barrier permeability
Ki values from DCE-MRI and quantities of plasma Lipopolysaccharide binding protein
Time frame: 25 minutes post contrast administration and baseline (fasting) LBP
Correlation between BBB permeability and gut barrier permeability
Ki values from DCE-MRI and quantities of plasma soluble cluster of differentiation 14
Time frame: 25 minutes post contrast administration and baseline (fasting) sCD14
Correlation between BBB permeability and gut barrier permeability
Ki values from DCE-MRI and full blood bacterial DNA
Time frame: 25 minutes post contrast administration and postprandial AUC of full blood bacterial DNA
Correlation between BBB permeability and markers of neuronal damage
Ki values from DCE-MRI and quantities of plasma Amyloid beta
Time frame: 25 minutes post contrast administration and baseline (fasting) Amyloid beta
Correlation between BBB permeability and markers of neuronal damage
Ki values from DCE-MRI and quantities of plasma P-Tau
Time frame: 25 minutes post contrast administration and baseline (fasting) P-Tau
Correlation between BBB permeability and markers of neuronal damage
Ki values from DCE-MRI and quantities of plasma NfL
Time frame: 25 minutes post contrast administration and baseline (fasting) NfL
Correlation between BBB permeability and markers of neuronal damage
Ki values from DCE-MRI and quantities of plasma GFAP
Time frame: 25 minutes post contrast administration and baseline (fasting) GFAP
Correlation between BBB permeability and markers of neuronal damage
Ki values from DCE-MRI and quantities of plasma Alfa-Synuclein
Time frame: 25 minutes post contrast administration and baseline (fasting) Alfa-Synuclein
Correlation between BBB permeability and systemic inflammation
Ki values from DCE-MRI and quantities of plasma High sensitivity CRP
Time frame: 25 minutes post contrast administration and baseline (fasting) HS CRP
Correlation between BBB permeability and systemic inflammation
Ki values from DCE-MRI and quantities of plasma TNF alfa
Time frame: 25 minutes post contrast administration and baseline (fasting) TNF alfa
Correlation between BBB permeability and systemic inflammation
Ki values from DCE-MRI and quantities of plasma IL 1 beta
Time frame: 25 minutes post contrast administration and baseline (fasting) IL 1 beta
Correlation between BBB permeability and metabolic markers
Ki values from DCE-MRI and Body mass index
Time frame: 25 minutes post contrast administration and body mass index
Correlation between BBB permeability and metabolic markers
Ki values from DCE-MRI and bioimpedance-assessed body fat
Time frame: 25 minutes post contrast administration and bioimpedance-assessed body fat
Correlation between BBB permeability and metabolic markers
Ki values from DCE-MRI and plasma Glucose
Time frame: 25 minutes post contrast administration and baseline (fasting) Glucose
Correlation between BBB permeability and metabolic markers
Ki values from DCE-MRI and plasma HbA1c
Time frame: 25 minutes post contrast administration and baseline (fasting) HbA1c
Correlation between BBB permeability and metabolic markers
Ki values from DCE-MRI and plasma Insulin
Time frame: 25 minutes post contrast administration and baseline (fasting) Insulin
Correlation between BBB permeability and metabolic markers
Ki values from DCE-MRI and plasma HDL cholesterol
Time frame: 25 minutes post contrast administration and baseline (fasting) HDL cholesterol
Correlation between BBB permeability and metabolic markers
Ki values from DCE-MRI and plasma Triglycerides
Time frame: 25 minutes post contrast administration and baseline (fasting) Triglycerides
Correlation between BBB permeability and metabolic markers
Ki values from DCE-MRI and plasma LDL cholesterol
Time frame: 25 minutes post contrast administration and baseline (fasting) LDL cholesterol
Correlation between BBB permeability and metabolic markers
Ki values from DCE-MRI and plasma VLDL cholesterol
Time frame: 25 minutes post contrast administration and baseline (fasting) VLDL cholesterol
Correlation between BBB permeability and metabolic markers
Ki values from DCE-MRI and plasma ALT
Time frame: 25 minutes post contrast administration and baseline (fasting) ALT

Study locations

1 site

Herlev Gentofte Hospital
Hellerup, 2900, Denmark

References and documents

Individual participant data

Plan to share: Undecided

No publications or documents are linked to this record.

Updates

Tracking since Sep 25, 2026

No changes since tracking began. The registry record was last updated on Feb 18, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗

Registry details

Key details

Study ID: NCT06787001
Lead sponsor: University Hospital, Gentofte, Copenhagen
Collaborators: University of Copenhagen
Responsible party: Asger Lund, MD (Assoc. Prof., University Hospital, Gentofte, Copenhagen) — Principal investigator
First posted: Jan 22, 2025
Start date: Apr 1, 2025
Primary completion: Feb 17, 2026
Completion: Feb 17, 2026
Last update: Feb 18, 2026

Oversight

Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: No

View the source record on ClinicalTrials.gov ↗

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