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Trial registered on ANZCTR


Registration number
ACTRN12623000570684
Ethics application status
Approved
Date submitted
3/05/2023
Date registered
25/05/2023
Date last updated
11/04/2024
Date data sharing statement initially provided
25/05/2023
Type of registration
Prospectively registered

Titles & IDs
Public title
Function of Lactic Acid-bacteria to Support Health
Scientific title
Investigation of the impact of two probiotic strains on psychological wellbeing, gut health and Immunity in adults - a randomised, double blind, placebo controlled, intervention study.
Secondary ID [1] 309554 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Mental Well Being 329852 0
Gut Health 329853 0
Condition category
Condition code
Mental Health 326761 326761 0 0
Studies of normal psychology, cognitive function and behaviour
Oral and Gastrointestinal 326762 326762 0 0
Normal oral and gastrointestinal development and function
Inflammatory and Immune System 326763 326763 0 0
Normal development and function of the immune system

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This is a randomised, double blind, placebo controlled, intervention study with five arms. The study will recruit 765 health adults between the ages 25-65 years old from the general population Nationwide in New Zealand. Participants will be randomly allocated to one of four treatment groups (two lactic acid probiotics strains, each at two different doses - 1x10^9 CFU and 1x10^10 CFU) or placebo.

The duration of the intervention period is 8 weeks, with one oral capsules taken daily with water (cold). The compliance will be monitored by participant returning the bottles with any left over capsules at the end of the study.

Intervention code [1] 325986 0
Prevention
Comparator / control treatment
The placebo capsules will contain maltodextrin only.
Maltodextrin is the excipient in the treatment capsules
Control group
Placebo

Outcomes
Primary outcome [1] 334621 0
The primary outcome of this study is to investigate the impact of two probiotic strains on psychological well being using Depression, Anxiety, and Stress Scale (DASS-21),
Timepoint [1] 334621 0
DASS 21 will be measured at baseline, 4 weeks, and at the end of the intervention period of 8 weeks.
Primary outcome [2] 334810 0
The primary outcome of this study is to investigate the impact of two probiotic strains on psychological well being using Perceived Stress Scale (PSS).
Timepoint [2] 334810 0
PSS will be measured at baseline and at end of 8 weeks intervention using the PSS scale score.
Primary outcome [3] 334811 0
The primary outcome of this study is to investigate the impact of two probiotic strains on psychological well being as measured by Pittsburgh Sleep Quality (PSQ) index
Timepoint [3] 334811 0
PSQ index will be measured at baseline and at the end of the intervention period of 8 weeks.
Secondary outcome [1] 422135 0
The primary outcome of this study is to investigate the impact of two probiotic strains on psychological well being as measured by plasma neurotransmitter metabolites
Timepoint [1] 422135 0
Plasma neurotransmitter metabolites will be measured at baseline and at the of the 8 weeks intervention period.
Secondary outcome [2] 422137 0
The primary outcome of this study is to investigate the impact of two probiotic strains on psychological well being as measured by salivary cortisol levels
Timepoint [2] 422137 0
Salivary cortisol levels will be measured at baseline and at the end of the 8 weeks Intervention period.
Secondary outcome [3] 422138 0
The secondary outcomes of this study is to assess the impact of two probiotic strains on gastrointestinal comfort as measured by the Bristol stool chart.
Timepoint [3] 422138 0
Bowel habits as measured by the Bristol stool chart will be assessed at baseline and end of study (8 weeks)
Secondary outcome [4] 422139 0
The secondary outcomes of this study is to assess the impact of two probiotic strains on gastrointestinal comfort as measured by Gastrointestinal Symptom Rating Scale.
Timepoint [4] 422139 0
Gastrointestinal Symptom Rating Scale assessment will conducted baseline and at end of the 8 weeks of intervention.
Secondary outcome [5] 422141 0
Secondary outcomes of this study is to assess the impact of two probiotic strains the participants immune system as measured by plasma cytokines
Timepoint [5] 422141 0
Plasma cytokines will be measured at baseline and at the end of the 8 weeks intervention period.
Secondary outcome [6] 422142 0
Secondary outcomes of this study is to assess the impact of two probiotic strains the participants immune system as measured by salivary IgA
Timepoint [6] 422142 0
Salivary IgA will be measured at baseline and at the of 8 weeks intervention period.

Eligibility
Key inclusion criteria
Healthy adults aged between 25-65 years
Currently living in New Zealand
Have access to a smart phone, internet, and computer.
Report moderate levels of perceived stress (as indicated by a score of 14 or above on the perceived stress scale).
Minimum age
25 Years
Maximum age
65 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Are currently taking medication for depression or anxiety prescribed by a doctor
Have had antibiotics within the previous four weeks
Regularly take probiotics or have taken a probiotic supplement within the last two weeks
Have been diagnosed by a doctor with Coeliac Disease, Inflammatory Bowel Disease, or Irritable Bowel Syndrome
Pregnant or breastfeeding

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Using the study ID number, participants will be randomly assigned to one of five groups.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Computer generated
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
Sample size calculation determined at 153/arm. This allows for 80% power to detect a 40% reduction in the standard deviation of stress scores in the intervention group using data from literature. This sample size accounts for an anticipated 20% attrition at the end of intervention and adjusts for multiple comparisons. Data will be analysed as intent to treat.
Change in scores between baseline and end of intervention will be compared for each probiotic group (combining both low and high dose), versus placebo.
A repeated measures analysis will compare the average number of illness days per week for each probiotic group compared to placebo. The number of discrete episodes of illness will be compared between the probiotic and placebo groups.
T-tests will be used to analyse differences between intervention groups compared to the placebo for salivary cortisol, cytokines and IgA.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 25422 0
New Zealand
State/province [1] 25422 0

Funding & Sponsors
Funding source category [1] 313746 0
Commercial sector/Industry
Name [1] 313746 0
Fonterra Research and Development Centre
Country [1] 313746 0
New Zealand
Primary sponsor type
Commercial sector/Industry
Name
Fonterra Research and Development Centre
Address
Dairy Farm Road, Fitzherbert West, Palmerston North 4442..
Country
New Zealand
Secondary sponsor category [1] 315563 0
None
Name [1] 315563 0
Address [1] 315563 0
Country [1] 315563 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 312917 0
Central - New Zealand Health and Disability Ethics Committee (HDEC)
Ethics committee address [1] 312917 0
PO Box 5013
Wellington 6140
Ethics committee country [1] 312917 0
New Zealand
Date submitted for ethics approval [1] 312917 0
13/04/2023
Approval date [1] 312917 0
18/12/2023
Ethics approval number [1] 312917 0

Summary
Brief summary
Probiotics are live microorganisms that help to maintain a healthy microbial composition in the gut. Growing evidence suggests that supporting healthy microbial balance in the gastrointestinal tract with probiotics can modulate the immune response, reduce respiratory infections, and reduce neuroinflammation associated with mood disorders.
While there are increasing studies looking at the mechanisms linking gut microbiota to physiological systems that regulate human health and disease, there is a need for high quality randomised controlled trials to investigate the impact of probiotic supplementation in human populations.

The aim of this study is to investigate the impact of two lactic acid probiotic strains on psychological wellbeing, common cold and flu symptoms, and gut health in adults, and if probiotic supplementation is associated with changes in biomarkers of immune system function, biomarkers of stress and inflammatory responses, and alterations in the gut microbiome.

This is a randomised double blinded controlled parallel intervention study where 765 participants will be recruited (nationwide across New Zealand) and randomly allocated into treatment (probiotic 1 or 2, and at one of the 2 doses) and placebo groups. Participant will consume 1 capsule daily over a period of 8 weeks. During the intervention period, health and wellness data will be collected via questionnaires, SMS and emails. Blood, faecal and saliva samples will be collected for biomarker analysis at base line and end of the study.
We hypothesise that probiotic will improve human psychological health and wellbeing, reduce the incidences and duration of the common cold and flu symptoms and negative gastrointestinal symptoms. We also hypothesise that probiotic supplementation in the human population will be associated with the reduction in pro-inflammatory markers normally associated with these health conditions.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 126326 0
Dr Rebecca Slykerman
Address 126326 0
Department of Psychological Medicine
Faculty of Medical and Health Sciences
Building 507
22-30 Park Ave, Grafton
Auckland 1023
University of Auckland
Country 126326 0
New Zealand
Phone 126326 0
+649923 1132
Fax 126326 0
Email 126326 0
Contact person for public queries
Name 126327 0
Shalome Bassett
Address 126327 0
Fonterra Research and Development Centre
Dairy Farm Road
Fitzherbert West
Palmerston North 4442
Country 126327 0
New Zealand
Phone 126327 0
+64272110894
Fax 126327 0
Email 126327 0
Contact person for scientific queries
Name 126328 0
Rebecca Slykerman
Address 126328 0
Department of Psychological Medicine
Faculty of Medical and Health Sciences
Building 507
22-30 Park Ave, Grafton
Auckland 1023
University of Auckland
Country 126328 0
New Zealand
Phone 126328 0
+649923 1132
Fax 126328 0
Email 126328 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.