Bacillus Subtilis in Parkinson's Disease

April 2, 2026 updated by: University of Edinburgh

Effects of Bacillus Subtilis on Blood and Gut Biomarkers in Parkinson's Disease

The aim of this study is to evaluate whether the administration of Bacillus Subtilis influences gut and blood biomarkers relevant to the proposed mechanism(s) of action, as well as being acceptable as a regular supplement for people with Parkinson's disease.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Following informed consent, participants will undergo screening. If eligible, they will be invited to attend a baseline visit (week 0) to complete clinical assessments and provide a faecal and blood sample before starting their assigned intervention. Each participant will be randomised 1:1 to visually identical capsules containing either Bacillus Subtilis or placebo to be taken for 24 weeks. Telephone follow-up will be performed at week 8 to ensure compliance and answer any participant questions. Repeat clinical assessments and faecal/blood sample collection will take place at weeks 24 (treatment end date) and 36 (to assess longevity of biomarker changes after the intervention has stopped). Faecal samples will be collected at home within seven days prior to the clinic visits and brought to the appointment. Microbiota composition in faecal samples and blood biomarkers will be analysed in participant samples. Motor and non-motor symptom rating scales will also be administered.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
26

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Norway
      • Stavanger, Norway
        • Norwegian Centre for Movement Disorders, Stavanger University Hospital
  • United Kingdom
      • Edinburgh, United Kingdom
        • NHS Lothian

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Diagnosis of Parkinson's disease
  • Able to provide written informed consent
  • Over 50 years old
  • Motor symptom duration over 12 months
  • Stable dopaminergic medication regime for at least 3 months

Exclusion Criteria:

  • Use of probiotic supplements and probiotic-fortified foods (such as probiotic drinks and yoghurts) within past 3 months
  • Use of antibiotics within past 3 months
  • Previous gastrointestinal surgery or chronic organic bowel disorder
  • History of clinically significant motor fluctuations
  • History of postural instability or falls
  • Current smoker
  • Known or suspected allergy to probiotics
  • Regular use of antacids, proton pump inhibitors, laxatives or anti-diarrheal drugs
  • Use of hypoglycaemic or diabetes drugs
  • Participation in clinical trial of investigational medicinal product within past 3 months
  • Co-morbidities or other factors that, in the opinion of the investigator, make the patient unlikely to comply with study protocol

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Bacillus Subtilis
Bacillus Subtilis 1 capsule once daily in the morning (consisting of 10x10^9 Colony Forming Units)
Dietary supplement: Bacillus Subtilis
Bacillus Subtilis 1 capsule once daily in the morning (consisting of 10x10^9 Colony Forming Units)
Placebo Comparator: Placebo
1 visually identical placebo capsule once daily in the morning using the same carrier (microcrystalline cellulose) as the active (but not containing Bacillus Subtilis)
Other: Placebo
1 visually identical placebo capsule once daily in the morning using the same carrier (microcrystalline cellulose) as the active (but not containing Bacillus Subtilis)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
To assess the effect of Bacillus Subtilis on gut microbiome
Time Frame: 24 weeks
Changes in presence and abundance of Bacillus Subtilis and other bacteria in faeces following probiotic administration versus placebo. Non-parametric tests (such as Wilcoxon signed-rank test and permutational multivariate analysis of variance) will be used for alpha and beta diversity analyses, and to identify genera that have significantly changed in abundance.
24 weeks
To assess the effects of Bacillus Subtilis on blood biomarkers (sphingolipid profile)
Time Frame: 24 weeks
Changes in sphingolipids following Bacillus Subtilis administration versus placebo measured using liquid chromatography-mass spectrometry
24 weeks
To assess the effects of Bacillus Subtilis on blood biomarkers (pro-inflammatory cytokines)
Time Frame: 24 weeks
Changes in pro-inflammatory cytokines following Bacillus Subtilis administration versus placebo measured using V-PLEX Proinflammatory Panel 1 Human Kit
24 weeks
To assess the effects of Bacillus Subtilis on blood biomarkers (neurofilament light chain)
Time Frame: 24 weeks
Changes in neurofilament light chain following Bacillus Subtilis administration versus placebo measured using Single Molecule Array assay
24 weeks
To assess the effects of Bacillus Subtilis on blood biomarkers (alpha-synuclein species)
Time Frame: 24 weeks
Changes in alpha synuclein species following Bacillus Subtilis administration versus placebo measured using α-syn real-time quaking-induced conversion assays
24 weeks
To assess the effects of Bacillus Subtilis on blood biomarkers (lipid profile)
Time Frame: 24 weeks
Changes in cholesterols/triglycerides following Bacillus Subtilis administration versus placebo
24 weeks
To assess the effects of Bacillus Subtilis on blood biomarkers (fasting glucose)
Time Frame: 24 weeks
Changes in fasting glucose following Bacillus Subtilis administration versus placebo
24 weeks
To assess the effects of Bacillus Subtilis on blood biomarkers (haemoglobin A1C)
Time Frame: 24 weeks
Changes in haemoglobin A1C following Bacillus Subtilis administration versus placebo
24 weeks
To evaluate the acceptability of Bacillus Subtilis administration in PD patients
Time Frame: 24 weeks
Descriptive analysis of custom-designed Acceptability Questionnaire which includes four questions on number of missed doses, ease of swallowing, daily dosing schedule, and any other barriers to tablet compliance.
24 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
To evaluate the correlation between changes in gut and blood biomarkers following B. subtilis administration and motor/non-motor symptoms
Time Frame: 24 weeks
Correlation between Primary Objectives 1 and 2 and motor/non-motor symptoms: Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Movement Disorder Society Non-Motor Rating Scale (MDS-NMS), Montreal Cognitive Assessment (MoCA) and Parkinson's Disease Questionnaire (PDQ-39)
24 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Edinburgh

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Helse Stavanger HF
ADM Protexin

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Chair: David P Breen, MBChB, NHS Lothian

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 2, 2023

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 5, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
November 20, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 27, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 27, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 5, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 8, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 2, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 22/WS/0100

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings