Depression Mental and Behavioural Disorders
Conditions
Interventions
The pilot will be conducted over 14 weeks. 106 participants will be randomly allocated, using a computer generator (Sealed Envelope) to ensure double-blindedness, into two groups. Group 1 will be com
Sponsors
Symprove UK
Eligibility
Sex/Gender
All
Age
18 Years to 60 Years
Inclusion criteria
Inclusion criteria: 1. Depressive disorder diagnosed by the International Classification of Diseases (ICD)-11 2. Age 18 to 60 years 3. HAM-D17 score of 17 and PHQ-9 score of 10 4. Therapeutic antidepressant dose unchanged in the prior 3 weeks
Exclusion criteria
Exclusion criteria: 1. Pregnancy 2. An infection/vaccination and/or antibiotics 3. Supplementation with pro- or prebiotics 4. Autoimmune disease, in?ammatory bowel disease, coeliac disease 5. BMI >35 kg/m² 6. Cancer 7. Atherosclerotic cardiovascular disease (ASCVD), ischaemic heart disease (IHD), transient ischaemic attack (TIA ), peripheral arterial disease (PAD) 8. Kidney failure with estimated glomerular filtration rate (eGFR) 4.2 µIU/ml) 10. Psychiatric comorbidities of psychosis, emotionally unstable personality disorder (EUPD), eating disorder, obsessive compulsive disorder (OCD) and neurodevelopmental disorders 11. Formal psychological interventions 12. Concomitant medication of benzodiazepines, z drugs and quetiapine 13. Regular treatment (more than 3 days a week) with proton pump inhibitors, metformin, laxatives, systemic steroids, or non-steroidal anti-inflammatories 14. Significant change in dietary, smoking pattern or daily physical activity in the previous 4 weeks 15. High suicide risk, assessed by Columbia Suicide Severity Rating Scale (C-SSRS) 16. Substance or alcohol misuse 17. Participation in, or recently participated in, another study involving interventions which might affect the study outcomes 18. Any other condition which would affect the compliance or safety of the individual
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Current primary outcome measure as of 20/08/2025: Quality of life examined over 12 weeks using validated questionnaires World Health Organization Quality-of-Life Scale (WHOQOL-BREF) and the Quality of Life in Depression Scale (QLDS) at baseline week 2 and endpoint week 14 Previous primary outcome measure: Depression symptoms will be assessed using the Hamilton Depression Scale (HAM-D17) and Patient Health Questionnaire (PHQ-9) at the commencement and conclusion of the pilot at week 1 and week 14 | — |
Secondary
| Measure | Time frame |
|---|---|
| Current secondary outcome measures as of 20/08/2025: 1. Lipid profile, cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglycerides measured with the point-of-care Cardiochek at baseline week 2 and endpoint week 14 2. High sensitivity C-reactive protein (hs-CRP) measured with point of care Eurolyser at baseline week 2 and endpoint week 14 Tertiary outcome measures: Preliminary changes in depressive and gastrointestinal symptoms assessed using the validated questionnaires Hamilton Depression Scale 17 items (HAM-D17), Patient Health Questionnaire (PHQ-9) and Gastrointestinal Symptoms Rating Scale (GSRS). at baseline (week 2) and endpoint (week 14) Feasibility outcomes: 1. Recruitment: Ability to recruit =20 participants per month across participating sites until the target sample of 106 participants is achieved. Timeline from initiation of study to 6 months. 2. Retention: Retention of =50 % of enrolled participants with dropout limited to =15% from baseline (week 2) to endpoint (week 14). 3. Adherence: Adherence defined as participants taking =80% of the allocated probiotic doses between baseline (week 2) and endpoint (week 14). 4. Acceptability and data completeness: Acceptability of study procedures assessed by the completeness of outcome data, defined as =80% of planned questionnaires and biological samples collected between baseline (week 2) and endpoint (week 14). Previous secondary outcome measures: 1. Lipid profile, cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglycerides measured with point-of-care Cardiochek at week 2 and week 14 2. High sensitivity C-reactive protein (hs-CRP) measured with point of care Eurolyser at week 2 and week 14 | — |
Countries
England, United Kingdom
Contacts
Public ContactPaul Conroy
Outcome results
None listed