The ANZCTR website will be unavailable from 1-2pm (AEST) on Wednesday the 19th of June for website maintenance. Please be sure to log out of the system in order to avoid any loss of data.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
Impact of a probiotic supplement on post-quake psychological distress and related biomarkers
Scientific title
An investigation of the effects of a probiotic supplement on post-quake psychological distress and related biomarkers: a double-blind randomized placebo controlled trial with open label extension in people who were in Christchurch at the time of the one of the major earthquakes
Secondary ID [1] 280540 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Stress 286538 0
Depression 286539 0
Physical health 286565 0
Condition category
Condition code
Mental Health 286804 286804 0 0
Other mental health disorders
Inflammatory and Immune System 286805 286805 0 0
Other inflammatory or immune system disorders
Diet and Nutrition 286835 286835 0 0
Other diet and nutrition disorders

Study type
Description of intervention(s) / exposure
Double-blind randomized controlled trial (RCT) comparing a probiotic supplement (Probio'Stick) with a placebo followed by an open-label extension. The intervention requires the intake of a probiotic formula called Probio'Stick and containing two bacterial strains: Lactobacillus Helveticus R0052 and Bifidobacterium longum R0175 (3 x 109 colony-forming units/stick). More detailed information about the product can be found on the manufacturer's website, Participants consume 1 probiotic stick a day for a period of 8 weeks. The stick is in the form of orodispersible powder and can be taken also without water. Following the RCT, participants enter an open-label trial for a further 8 week period with the same dose of Probio'stick.
Intervention code [1] 284918 0
Treatment: Other
Comparator / control treatment
The placebo group receives a placebo formula of identical taste and appearance: it consists of xylitol, maltodextrin (maize-derived), plum flavour and malic acid. Participant consume 1 placebo stick a day for a total of eight weeks. They then enter an open label trial for a further 8 week period with the same dose of Probio'Stick (ingredients described above).
Control group

Primary outcome [1] 287177 0
CGI - clinical global impression for mood, stress, anxiety and energy - from 1 to 7 how much better or worse from very much improved to very much worse. Assessed by participant.
Timepoint [1] 287177 0
RCT: Baseline and fortnightly for all the 8 week period.

Open-label extension: fortnightly for the 8 week period.
Primary outcome [2] 287178 0
The Depression Anxiety and Stress Scale (DASS) is a self-report questionnaire aimed at assessing an individual's current severity of symptoms relating to depression, anxiety and stress.
Timepoint [2] 287178 0
RCT: Baseline and fortnightly for the 8 week period.

Open-label extension: fortnightly for the 8 week period.
Primary outcome [3] 287179 0
Assessment of biomarkers:

- salivary cortisol
- high-sensitive C-reactive protein (blood)
- homocysteine (blood)
Timepoint [3] 287179 0
Baseline and 8 weeks (end of RCT phase).
Secondary outcome [1] 297559 0
The Kessler Psychological Distress Scale (K-10) measures non specific psychological distress in the depression-anxiety spectrum.
Timepoint [1] 297559 0
RCT: Baseline and fortnightly for all the 8 week period.

Open-label extension: fortnightly for the 8 week period.
Secondary outcome [2] 297560 0
The Profile of Mood States (POMS) is a measure of psychological distress and includes seven different scale: depression, anxiety, fatigue, vigour, irritability, tension and confusion.
Timepoint [2] 297560 0
RCT: 8 weeks ( baseline and end of RCT phase).

Open-label extension: end of open-label phase.
Secondary outcome [3] 297561 0
The Brief COPE is a brief form of the COPE Inventory.
It consists of 14 scales of two items each and represents a useful instrument to identify coping strategies.
Timepoint [3] 297561 0
RCT: Baseline and fortnightly for all the 8 week period.

Open-label extension: fortnightly for all the 8 week period.
Secondary outcome [4] 297562 0
A visual analogue scale (EQ-VAS) from the EuroQol questionnaire will ask participants to rate their current health state.
Timepoint [4] 297562 0
RCT: Baseline and fortnightly for all the 8 week period.

Open-label extension: fortnightly for all the 8 week period.
Secondary outcome [5] 297563 0
The Pennebaker Inventory of Limbic Languidness (PILL) assesses self-reported physical symptoms.
Timepoint [5] 297563 0
RCT: Baseline and fortnightly for all the 8 week period.

Open-label extension: fortnightly for all the 8 week period.
Secondary outcome [6] 297564 0
Bristol Stool Form Scale (BSFS) is a self-administered instrument useful to classify the form of human faeces into 7 types according to the seven images provided in the chart. It is widely used in clinical research and practice as it demonstrated to be a good measure of intestinal transit and thus a good indicator of the level of constipation/diarrhea of the subject.
Timepoint [6] 297564 0
RCT: participants will rate their faeces over the first and the last week of the trial.
Open-label extension: participants will rate their faeces over the last week of the trial.

Key inclusion criteria
1. Participants are older than 16 years of age.
2. Each participant must have a level of understanding sufficient to complete the questionnaires and examinations required by the protocol and be considered reliable and compliant with the protocol.
3. Participants meet at least one score above the cut-offs of the Depression Anxiety and Stress scale(DASS; Lovibond & Lovibond, 1995).
4. Participants must have been in Christchurch at the time of the one of the major earthquake (September 4th 2010; February 22nd 2011; June 13th 2011; Dec 23rd 2011).
5. Participants are free of psychotropic medication for the trial.
6. Participants who have not recently, within the last 4 days, suffered illness or have signs of inflammation.
Minimum age
16 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
1. Neurological disorder involving brain or other central function (e.g., epilepsy, MS, narcolepsy).
2. Renal, hepatic, cardiovascular and respiratory diseases.
3. Any serious medical condition for which major medical interventions are anticipated during the duration of the trial.
4. Any patient known to have food allergy or to be allergic to the ingredients of the intervention.
5. Pregnancy or breastfeeding
6. Evidence of substance dependence within the previous month.
7. Any other medication with primarily central nervous system activity, including mood stabilizers. Participants must have been off of these medications for a minimum of four weeks prior to the trial.
8. Patients will be excluded temporarily if they have taken an oral antibiotic in the previous 6 weeks. If an antibiotic is begun during the course of the trial, that patient will be withdrawn from the study.
9. Any type of nutritional or herbal supplement (ginger, guarana, ginseng, dehydroepiandrosterone, melatonin, antioxidants, selenium, replacement hormones) known to have a centrally-acting effect, will result in a patient’s exclusion.
10. Any subject judged clinically to be at serious risk for suicide or violence in the opinion of the researchers.
11. Participants will be asked to minimize their intake of colas, tea, coffee, alcohol, cigarettes and illicit drugs. These substances will be monitored as part of the trial.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
If an individual meets the inclusion criteria and does not meet the exclusion criteria, he/she will be allocated to the next available number. All sticks( active ingredient or placebo) have been pre-packaged by the pharmacy which holds the randomisation code. A sealed envelope is contained within each stick package only to be opened in an emergency (i.e. a patient deteriorates significantly).
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
We will set up 4 tables of random numbers (mix of 1s and 2s representing the probiotic or placebo). We will give these four sets to the Pharmacy (David Pugh-Williams at the Christchurch Public Hospital), who will selected one of them --- and of course we will not know which one. The study pharmacist prepares in advance a participant kit which contains all the medication bottles required over the eight weeks for each participant. These kits are sequentially numbered and allocated to placebo or probiotic based on the randomisation list. Once a participant’s eligibility has been confirmed they will be allocated the next sequentially numbered kit and dispensed adequate powder for the duration of the trial. In this manner neither the participant nor the PI nor the clinician nor the observer, assessing the participant’s outcomes are aware of the participant’s allocated study group.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

Intervention assignment
Other design features
The randomized phase is followed with an open-label trial
Not Applicable
Type of endpoint/s
Statistical methods / analysis

Recruitment status
Reason for early stopping/withdrawal
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 4330 0
New Zealand
State/province [1] 4330 0

Funding & Sponsors
Funding source category [1] 285309 0
Name [1] 285309 0
University of Canterbury
Country [1] 285309 0
New Zealand
Primary sponsor type
University of Canterbury
Department of Psychology
Private Bag 4800
New Zealand
Secondary sponsor category [1] 284319 0
Name [1] 284319 0
Address [1] 284319 0
Country [1] 284319 0

Ethics approval
Ethics application status
Ethics committee name [1] 287325 0
Upper South A Regional Ethics Committee
Ethics committee address [1] 287325 0
c/- Ministry of Health
Montgomery Watson Building
6 Hazeldean Road
Ethics committee country [1] 287325 0
New Zealand
Date submitted for ethics approval [1] 287325 0
Approval date [1] 287325 0
Ethics approval number [1] 287325 0

Brief summary
The purpose of this study is to evaluate the effect of a probiotic supplement on the treatment of psychological symptoms, such as stress, anxiety and depression, associated with the earthquake experience and its negative consequences on quality of life. Seismic events can cause serious problems of adaptation and lead to significant changes which can affect the daily management of your life. If these situations persist, they can promote an increase in the level of important biological indicators (biomarkers) that regulate your stress response, with consequent harmful effects on your health. Recent studies have demonstrated that the gut is able to communicate with the brain and that the consumption of beneficial gut bacteria can improve psychological symptoms and reduce the level of some relevant biomarkers. The aim of this research is to assess the therapeutic role of a specific probiotic formula in treating these stress-related symptoms.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 34216 0
A/Prof Julia Rucklidge
Address 34216 0
University of Canterbury
Private Bag 4800
Christchurch New Zealand
Country 34216 0
New Zealand
Phone 34216 0
Fax 34216 0
Email 34216 0
Contact person for public queries
Name 17463 0
A/Prof Assoc. Prof. Julia Rucklidge
Address 17463 0
Dept of Psychology
University of Canterbury
Private bag 4800
Country 17463 0
New Zealand
Phone 17463 0
6433642987 ext 7959
Fax 17463 0
Email 17463 0
Contact person for scientific queries
Name 8391 0
A/Prof Ass. Prof. Julia Rucklidge
Address 8391 0
Dept of Psychology
University of Canterbury
Private bag 4800
Country 8391 0
New Zealand
Phone 8391 0
+6433642987 ext 7959
Fax 8391 0
Email 8391 0

No information has been provided regarding IPD availability

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.