Brief Summary

Neurodegenerative diseases are a major health concern due to their growing societal implications and economic costs. The identification of early markers of pathogenic mechanisms is one of the current main challenges. The gut-brain axis has become a primary target because of its transversal role across the neurodegenerative spectrum and its effect on cognition. However, despite recent progress, how changes in the gut-microbiota composition can affect the human brain is still unclear. The goal of this observational study is to characterise the gut-microbiota composition associated with alterations in brain structure and function during the ageing process and across neurodegenerative disorders. This is based on recent studies showing that changes in the human brain and in the microbiota composition, can indicate very sensitively and in a predictive way pathological development and, consequently, be used as markers of neurodegenerative diseases. The main questions it aims to answer are:

How variation in the gut-microbiota composition correlates with the normal brain ageing trajectory?
How dysregulation in the gut-microbiota correlates with pathological changes in brain regions in specific neurodegenerative disorders?
Can the impact of the gut-microbiota on the brain be modulated by blood biomarkers? The investigators will recruit 40 young healthy participants, 40 old healthy participants, 40 participants with prodromal Alzheimer's Disease, 40 participants with Parkinson's Disease and 40 participants with Multiple Sclerosis. Participants will undergo the following examinations:
Magnetic Resonance Imaging
Analysis of a stool sample
Analysis of a blood sample
Neuropsychological assessment
Questionnaires on eating habits

Trial Health

On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment

200

participants targeted

Target at P75+ for all trials

Timeline

11mo left

Started May 2023

Longer than P75 for all trials

Geographic Reach

1 country

3 active sites

Status

recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

4 years study duration

Study Progress78%

May 2023Apr 2027

Study Start

First participant enrolled

May 1, 2023

Completed

1 month until next milestone

First Submitted

Initial submission to the registry

June 9, 2023

Completed

27 days until next milestone

First Posted

Study publicly available on registry

July 6, 2023

Completed

3.8 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

April 30, 2027

Expected

Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

April 30, 2027

Last Updated

January 9, 2026

Status Verified

January 1, 2026

Enrollment Period

4 years

First QC Date

June 9, 2023

Last Update Submit

January 7, 2026

Conditions

Healthy Prodromal Alzheimer's Disease Parkinson Disease Multiple Sclerosis

Keywords

MRIMicrobiotaStool sampleBlood sampleNeuropsychological assessmentNeuroimagingBiomarkers for brain disorders

Outcome Measures

Primary Outcomes (2)

Brain structural and functional properties
Brain structural and functional properties will be derived from a multi-modal Magnetic Resonance Imaging protocol.
Day 1
Microbiome profile
Microbiome profile will be derived from a stool sample obtained from participants.
Day 1

Secondary Outcomes (3)

Cognitive functioning
Day 1
Concentration of blood inflammatory markers
Day 1
Eating habits
Day 1

Study Arms (5)

Young Healthy Subjects (N = 40)

* 20-50 years old * Cognitively healthy (Mini-Mental State examination ≥ 26) * Absence of significant neurological disorders

Diagnostic Test: Magnetic Resonance ImagingBehavioral: Neuropsychological protocolBehavioral: Eating habitsDiagnostic Test: Microbiome analysesDiagnostic Test: Inflammatory markers

Old Healthy Subjects (N = 40)

* 60-90 years old * Cognitively healthy (Mini-Mental State examination ≥ 26) * Absence of significant neurological disorders

Diagnostic Test: Magnetic Resonance ImagingBehavioral: Neuropsychological protocolBehavioral: Eating habitsDiagnostic Test: Microbiome analysesDiagnostic Test: Inflammatory markers

Patients with prodromal Alzheimer's Disease (N = 40)

* Subjective cognitive complaint (corroborated by the informant) * Episodic memory deficit on neuropsychological testing * Clinical Dementia Rating = 0.5 * Mini-Mental State Examination (MMSE) \> 23 * Independently functioning in activities of daily living

Diagnostic Test: Magnetic Resonance ImagingBehavioral: Neuropsychological protocolBehavioral: Eating habitsDiagnostic Test: Microbiome analysesDiagnostic Test: Inflammatory markersDiagnostic Test: Alzheimer's Disease biomarkers

Patients with Parkinson's Disease (N = 40)

* Recent diagnosis of Parkinson's Disease * Mild-moderate score at the Unified Parkinson's Disease Rating Scale (UPDRS) * Cognitively healthy (Mini-Mental State examination ≥ 26) * In case of taking medications for Parkinson's Disease: stable dosage for at least 6 months

Diagnostic Test: Magnetic Resonance ImagingBehavioral: Neuropsychological protocolBehavioral: Eating habitsDiagnostic Test: Microbiome analysesDiagnostic Test: Inflammatory markers

Patients with Multiple Sclerosis (N = 40)

* Recent diagnosis of relapsing-remitting Multiple Sclerosis * Expanded Disability Status Scale score ≤ 4.0 * Cognitively healthy (Mini-Mental State examination ≥ 26) * In case of taking medications for Multiple Sclerosis: stable dosage for at least 6 months

Diagnostic Test: Magnetic Resonance ImagingBehavioral: Neuropsychological protocolBehavioral: Eating habitsDiagnostic Test: Microbiome analysesDiagnostic Test: Inflammatory markers