The four active or placebo enemas will be administered over four consecutive days to each participant by a research nurse. Assessments will be conducted at baseline, and then every two-weeks until the primary end point (eight weeks). A further follow-up assessment will then occur at week 26 to capture long-term safety data. An outline of the study schedule is provided in Table 1 and the appointment schedule is summarised in Fig. 1. Participants, investigators, assessors, and study statisticians will be blinded to group allocation. This protocol is reported as per the Standard Protocol Items: Recommended for Intervention Trials (SPIRIT) guidelines (53), and the CONSORT extension for pilot and feasibility trials checklist (54). All study procedures will be concordant with Good Clinical Practice (GCP) principles. The consent procedure is described below under the heading Consent and Enrolment.
[Table 1 is located at end of document]
Study setting
The trial will be conducted at a dedicated clinical trials facility at University Hospital Geelong, Victoria. This space includes appropriate consultation spaces and on-site equipment for intervention delivery and the collection of biological samples. This study will consist of 10 study appointments, six of which are in-person and four via telehealth (see Table 1 and Fig. 1).
The collection of blood samples will be performed by a qualified research nurse or phlebotomist, where markers of cardiovascular and metabolic disease risk (e.g. lipids, HbA1c and blood glucose) will be assayed. Additional blood samples will be collected and transported to the Geelong Centre for Emerging and Infectious Disease (GCEID) laboratories in Geelong for additional blood analyses and long-term storage.
Stool samples will be collected by participants at home using a Microba (Queensland, Australia) stool sampling kit. Participants will then return the completed kits to research personnel at their study appointments. These stool samples will be de-identified (marked with a participant code only) and sent to Microba for metagenomic analyses.
Study population
This study aims to recruit 15 participants, aged 18 to 65 years of age, with a DSM-5 diagnosis of MDD (confirmed by a psychiatrist using the Structured Clinical Interview for DSM-5 (SCID-5) MDD module) (55) of moderate-to-severe range (defined as a Montgomery Asberg Depression Rating Scale (MADRS) score of greater than or equal to 20) (56). Eligibility criteria are outlined in Table 2. The recruitment strategies are outlined in Table 3. Once participants have given consent and been screened and determined eligible for entry into the study, they will be randomised to either active FMT enema or placebo enema, which will be delivered on four consecutive days in the first week of the study. Participants will then be followed up fortnightly for eight weeks, with a final appointment at week 26 to capture long term safety data. The participant schedule and study outcomes are summarised in Table 1 and Fig. 1
Table 2
Eligibility criteria of participants enrolled in the Moving Moods Pilot Study.
Inclusion Criteria:
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1. Adults (age 18–65 years)
2. MDD according to Structured Clinical Interview for DSM-5 (SCID-5) MDD module
3. Moderate-to-severe score on MADRS (i.e., score of greater than or equal to 20)
4. Stable treatment (ie., pharmacological and psychological) for one month prior to commencing trial
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Exclusion criteria:
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1. Active suicidality (a MADRS suicide item score of 5 or 6)
2. Use of probiotics, antibiotics, or any experimental drug in the one month prior to study entry
3. Serious gastrointestinal conditions (including inflammatory bowel disease, bowel cancer, diverticular disease, or a history of major bowel surgery, but not including IBS, chronic diarrhoea, or constipation)
4. Pregnancy or breastfeeding (pregnancy will be excluded using a urine pregnancy test at baseline)
5. Major comorbid psychiatric disturbances including bipolar disorder, a primary psychotic illness, obsessive-compulsive disorder, anorexia nervosa or bulimia nervosa
6. Active substance-use disorder, defined as a score of 6 or greater on the brief Drug Abuse Screening Test (DAST-10), and/or a score of 16 or greater in the Alcohol Use Disorders Identification Test (AUDIT)
7. Inability to read and understand the participant information and informed consent form
8. Patients with a history of severe anaphylactic or anaphylactoid food allergy
9. A condition that could jeopardize the safety or rights of the subject, make it unlikely for the subject to complete the study, or confound the results of the study
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Table 3
1. Flyers will be displayed in the waiting rooms of key recruitment sites
2. Advertisements through social media
3. Clinicians at key recruitment sites will advise of appropriate patients for the trial
4. Trial Facts or HealthShare, which are services connecting patients and doctors, will identify appropriate participants for the trial. These will be utilised only if the above strategies are insufficient.
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Follow up appointments will be conducted by a qualified member of the research team. The data collected at these assessments are summarised in Table 1.
Outcomes
The study appointment schedule is detailed in Table 1. Primary, secondary, and exploratory outcomes are described below.
Primary outcome measures
The primary outcomes for this study are 1) the feasibility and 2) safety of FMT as an adjunctive treatment for MDD in adults. The study outcomes, participant appointment schedule, and study timeline are outlined in Table 1 and Fig. 1.
Feasibility will be considered as a composite outcome, measured by the following:
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the ability to meet recruitment targets (measured by recruitment logs, comparing actual recruitment against projected targets)
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participant retention and completion rates (measured by attrition rates and completeness of data)
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adherence to intended protocol (measured by completion of intervention as planned, missed appointments, technical difficulties arising, and completeness of study data)
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participant acceptability (measured using the TransCelerate Study Participant Feedback Questionnaire, plus the addition of questions designed specifically for this study)
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robustness of study methodology, including effectiveness of blinding (measured qualitatively based on feedback from researchers throughout and at the conclusion of the study, and a participant and researcher survey to assess blinding)
Safety of FMT as an adjunctive treatment in adults will be measured by an assessment of adverse events. These data will be collected through direct observations by the study nurse during administration of the intervention, and via participant reporting during the intervention and each appointment thereafter (measured at weeks 0, 2, 4, 6, 8 and 26). Participants will also be encouraged to contact the research team at any time to report adverse events outside of study appointments.
Secondary outcome measures
The secondary outcome measure of this study is changes in gut microbiota, which will be measured via the following:
- The degree of change in gut microbiota composition in recipients, which will be assessed by observing changes in gut microbiota composition (alpha diversity, beta diversity, differential abundance of species) at 2- and 8-weeks post-intervention compared with baseline.
- The degree of microbial ‘engraftment’: degree to which changes in microbiota of recipients are concordant with the microbiota profiles of the donor stool post active FMT and compared with placebo enema.
- Donor vs recipient at baseline (0 weeks)
- Donor vs recipient at 2 weeks (active FMT compared with placebo group)
- Donor vs recipient at 8 weeks (active FMT compared with placebo group)
Exploratory Outcome Measures
The following data will be collected as part of the primary feasibility outcome, described above. However, given the small sample size, it is expected that the study will be underpowered to measure significant changes in any of the following outcome measures. As such, these outcomes are considered “exploratory”. To avoid type-I error inflation due to multiple comparisons, we aim to only record summary descriptions of these clinical outcomes. These exploratory outcomes are as follows:
- Between-group differential change from baseline and weeks 2, 4, 6 and 8 in mental health symptoms as measured by the Montgomery-Asberg Depression Rating Scale (MADRS) and the Depression-Anxiety Stress Scale (DASS)
- Between-group differential change from baseline and weeks 2, 4, 6 and 8 in quality of life as measured by the Assessment of Quality of Life-8 Dimension (AQoL-8D); this scale also allows the calculation of preference-based outcomes also known as utilities. Utility values will be used to calculate quality adjusted life years (QALYs), a common metric used in economic evaluations
- Between-group differential change from baseline and weeks 2, 4, 6 and 8 in sleep as measured by the Pittsburgh Sleep Quality Index
- Between-group differential change from baseline and weeks 2, 4, 6 and 8 in level of function as measured by the Sheehan Disability Scale
- Between-group differential change from baseline and weeks 2, 4, 6 and 8 in gut symptomatology as measured by the Gastrointestinal Symptom Rating Scale (GSRS)
- Between-group differential change from baseline and weeks 2 and 8 in in blood biomarkers of neurogenesis (e.g. brain-derived neurotrophic factor)
- Between-group differential change from baseline and weeks 2 and 8 in cardiometabolic blood parameters (e.g, random lipid profile, random blood sugar levels and HbA1c)
- Between-group differential change from baseline and weeks 2 and 8 in metabolic and cardiovascular risk factors assessed via physical exam, including heart rate, blood pressure, height, and weight
- Cost effectiveness will be assessed from both health sector and societal perspectives. The cost of FMT via enema will be estimated and added to the cost of lost productivity and health care resources utilised by participants over the course of the trial using the Resource Utilization Questionnaire (measured at weeks 0 and 8)
- Between-group differential change from baseline and weeks 2, 4, 6 and 8 in self rated overall improvement assessed using the Patient Global Impression of Change
- Between-group differential change from baseline and weeks 2 and 8 in inflammation (e.g., macrophage inhibitory factor, interleukins 1b, 1ra, 6 and 10, soluble CD14, and high sensitivity C-reactive protein) will be measured in plasma and/or serum using immunoassays (e.g. solid phase sandwich ELISA assay)
- Between-group differential change from baseline and weeks 2 and 8 in gut permeability (e.g., lipopolysaccharide binding protein and zonulin) will be measured in plasma and/or serum using immunoassays (e.g. solid phase sandwich ELISA assay)
Feasibility targets
Table 4 outlines pre-specified targets identified by the research team as a minimum standard that would indicate that the study design was feasible. These targets will also assist the study team to identify aspects of the trial that may need to be amended to improve future, large-scale trials.
Table 4
Target area
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Feasibility target
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Recruitment
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Successful enrolment of n = 15 participants across a 6-month active recruitment period
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Retention
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A minimum of n = 10 participants to complete study until the 8-week primary endpoint (i.e. a 33% attrition rate).
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Adherence to protocol
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Participants should:
1) Receive two of the total four enemas
2) Attend their baseline, week 2 and week 8 appointments
3) Provide baseline and week 2 stool samples
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Safety
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Nil severe and/or serious adverse events rated as likely due to study intervention in the active FMT group.
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Adequacy of blinding
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The best achievable outcome for adequacy blinding is participants and researchers correctly guessing allocation at a rate of 50% (the rate due to chance). Whilst we are not likely to be statistically powered to measure this outcome, we aim to reach an outcome approaching 50%.
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Sample size, power, and statistics
Feasibility analysis
As this is a feasibility study, it is not designed or powered to evaluate statistically significant changes in any of the parameters being assessed. Therefore, a qualitative synthesis of feasibility data will be reported.
Gut microbiota analyses
Longitudinal analysis of changes in gut microbiome composition will be performed within the R statistical environment. Measures of gut microbiota alpha-diversity (e.g., Shannon Index, Simpson Index, Chao-1, ACE, evenness, Faith’s phylogenetic diversity) and beta-diversity (e.g., Bray-Curtis, Jaccard, Aitchison distance) will be calculated for donors (baseline) and recipients (three timepoints: baseline, 2 weeks, 8 weeks post intervention). Differences in alpha-diversity between donors and recipients (between groups) will be tested using the Mann-Whitney test and between each time point (within groups) will be compared using Kruskal-Wallis non-parametric test. An appropriate method will be used to correct for multiple comparisons. Permutational multivariate analysis of variance (PERMANOVA) and visualization with principal coordinate analysis (PCoA) will be used to estimate any differences in gut microbiota community structure (beta-diversity) between donors and recipients and in recipients over time. Differential abundance analyses will be conducted to compare the taxonomic composition of gut microbiota between donors and recipients and in recipients over time.
Trial allocation, sequence generation and blinding
Allocation to treatment arms will be randomly assigned in a 2:1 ratio using permutated block randomisation. Unblinded researchers independent to the study team, utilising a simple randomisation method, will develop the randomisation sequence and assign participants to study arms. The unblinded researchers will allocate and package enema kits sequentially, and packaging will be identical to conceal treatment allocation and blinding. The study staff, investigators, trial biostatistician, nurses delivering the enemas, and participants will be blinded to group allocations.
Data storage and management
Participants will be allocated a unique study ID number on enrolment, and their data will be de-identified and coded with this unique study ID. Blood and stool samples collected will be stored in a minus 80-degree Celsius until analysis. Faecal samples will be sent to the Queensland-based laboratory, Microba, for metagenomic analysis. DNA will be extracted and then sequenced using an Illumina NovaSeq high-throughput sequencing platform. The sequences allow the microorganisms in the samples to be classified by comparing against reference databases so that the presence and abundance of the microorganisms present can be identified and reported. Questionnaire and other study data will be collected online and stored using the secure Deakin University REDCap server.
All written and electronic data, including source documents, informed consent forms, and ethics approval forms will be retained for at least 15 years from the end of the study, as is the GCP requirement for clinical trials. All research data from consenting participants, including gut microbiota sequencing data and pre-processing and analysis pipeline information, will also be stored in a secure data repository (Deakin Research Online) for long term preservation and/or reuse by other researchers with appropriate ethical approval/consideration from their institution (for example, meta-analyses).
Data analysis and reporting
Reporting of findings will be in accordance with CONSORT extension for pilot and feasibility trials (54). The study biostatistician responsible for the analysis of outcome data, as well as participants and patient assessors, will be blind to group allocation.
Impact of and response to participant withdrawal
Participants will be withdrawn from the study if they withdraw consent or at the discretion of the researcher given adverse events or loss to follow-up. Reasons for withdrawal will be documented, and participants will be asked whether they are willing to accept any further contact to assess short and longer-term safety.
Management of adverse events
Managing risk
On enrolment, all participants will be required to provide details for their current or preferred general practitioner. In the case of a participant reporting suicidal ideation, plan, or intent, (a MADRS suicide item score of 5 or 6), the researcher will strongly encourage the participant to contact their general practitioner, and the researcher will also attempt to contact the general practitioner directly. In the case that a more serious concern for the immediate safety of the patient arises, such as severe suicidality with immediate risk, or an unreported recent suicide attempt, the researcher will contact a psychiatrist member of the team or take immediate action to ensure participant safety. This may involve – with the participant’s consent - contacting the treating general practitioner or other treating clinician, assisting the person in accessing relevant care, for instance by contacting ambulance or psychiatric emergency services.
Safety Requirements
Study participants will be provided with contact details for the research team, and strongly encouraged to contact the research team at any point in the study to report adverse events or discuss concerns. In addition to this, there will be routine contact made every two weeks post intervention until the eight-week primary endpoint, and an additional 26-week follow-up, to assess adverse events or side effects. In the circumstance of a severe or serious adverse event, participants will be encouraged to attend medical services.
If a severe or serious adverse event occurs, the re-identification protocol may need to occur, so that treating clinicians can know whether the participant received the FMT intervention or the placebo. Each participant will be issued a unique identifying number on enrolment which will be linked to the intervention that they were allocated. The unblinded research assistant will be contacted to reveal the treatment allocation of the participant, only if necessary for their medical care.
A data safety monitoring board (DSMB) will be implemented comprising of a clinician, a statistician, and a pharmacist. All members of the DSMB will be independent of the research to avoid conflicts of interest. The role of the DSMB will be to oversee the safety of the study. This will involve reviewing the study protocol, PICF and consent procedures, safety monitoring procedures, procedures relating to confidentiality and adverse events arising during the course of the study. In the event of a severe or serious adverse event, the DSMB will be promptly notified and will decide on whether to pause recruitment or halt the study.
Ethical, regulatory and dessemenation aspects
Consent and enrolment
Following primary expression of interest, via any of the above listed recruitment pathways, eligible participants will be directed to the study webpage for more details, where they will be able to register an expression of interest to be contacted by a member of the study team. Potentially eligible participants will be provided with a PICF. They will also be asked to nominate a time for a member of the research team to call them to discuss the study further and book in an initial study appointment. Participants will be given the option of signing the PICF with a member of the research team either in-person or via telehealth. Signed consent must be provided prior to study enrolment.
Consent will also be obtained from participant to send reminder texts prior to appointments.
Should participants have any conditions or commitments that preclude them from participating immediately, participants will be asked to nominate their preferred starting date within the trial period. Consent will be obtained to send participants reminders via email and phone.
Consent will be confirmed again at the initial screening appointment. Participants will be made aware that they can withdraw consent (primary or extended) at any point
Plans for return of results of research to participants
At the conclusion of this study, a summary of results including aggregated results and their personal microbiome analysis report will be returned to participants via email or postal mail depending on their preference.
Plans for dissemination and publication of project outcomes
After approval by the coordinating principal investigator, sub-investigators, and statistician, results of the study will be published in peer-reviewed scientific journals and presented at scientific conferences and to lay audiences where applicable. Results will be published after termination of the study. The order of authors will be at the discretion of the coordinating investigators. Factors that the coordinating investigator may take into consideration are the following: securing funding for the study, participation in organising the study, participation in meetings and the on-going development of the study, manuscript preparation, and general involvement in the study.
Project closure processes
At the conclusion of the project, arrangements shall be made for retention of all data relating to the project (including raw and electronic data, and PICFs); this will be retained for at least 15 years following the closure of the database. With participant consent, biological products will be retained for up to 15 years, and contact details will be kept on record so that participants can be contacted again for participation in future research.
Plans for sharing and/or future use of data and/or follow-up research
This project is inter-departmental and interdisciplinary. Data will be shared between the respective groups involved in its execution. There are plans for future use of the data and product developed in this project. If this project proves to be feasible, our group intends to use the same or similar enema FMT product and protocol and test its efficacy in a larger randomised controlled trial powered to detect changes in depressive symptomatology.