Gut Feeling: Understanding the Mechanisms Underlying the Antidepressant Properties of Probiotics

Not Applicable

Completed

• Conditions: Major Depressive Disorder
• Interventions: Other: Placebo; Dietary Supplement: Multi-strain probiotic

• Registration Number: NCT03893162
• Lead Sponsor: King's College London

Brief Summary

Previous research has suggested that probiotics can improve depressive symptoms in patients with Major Depressive Disorder (MDD), particularly when used in addition to antidepressants. The aim of this exploratory pilot study is to improve the investigator's understanding of the mechanisms underlying these effects. This study will assess the effects of an 8-week double-blind placebo-controlled probiotic intervention on the gut microbiome, inflammatory marker levels, brain activity and neurotransmitter levels in patients with MDD and their relationship to changes in mood. This study will also recruit a group of demographically-matched healthy controls for gut microbiome comparison with the MDD group (non-interventional).

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2019-03-22
• Study First Submitted QC: 2019-03-27
• Study First Posted: 2019-03-28
• Study Start: 2019-07-01
• Status Verified: 2021-09
• Primary Completion: 2022-06-29
• Last Update Submitted: 2022-06-29
• Study Completion: 2022-06-30
• Last Update Posted: 2022-06-30

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 50

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	4 capsules daily for 8 weeks
Multi-strain probiotic "BioKult"	Multi-strain probiotic	4 capsules daily for 8 weeks

Primary Outcome Measures

Name	Time	Method
differences in gut microbiota between MDD and healthy volunteers	baseline	species diversity and abundance at the level of OTUs will be measured with 16SrRNA-based sequencing and compared between the two groups
gut microbiota in MDD	baseline	species diversity and abundance at the level of organisational taxonomic units (OTUs) will be measured with 16S ribosomal RNA (rRNA) sequencing
gut microbiota changes in MDD following probiotic intervention and their correlation to change in depressive symptoms	change from baseline to week 8	species diversity and abundance at the level of OTUs will be measured with 16SrRNA-based sequencing and depressive symptoms will be measured with the Inventory of Depressive Symptomatology Self-Report (IDS-SR) and the Hamilton Depression Rating Scale (HAM-D17)

Secondary Outcome Measures

Name	Time	Method
Neurotransmitters	change from baseline to week 8	levels of glutamate and gamma-aminobutyric acid (GABA) will be measured with Magnetic Resonance Imaging (MRS)
Blood	change from baseline to week 8	levels of tumor necrosis factor (TNF-a), interleukins IL-1β, IL-6, IL-17, and C-reactive protein (CRP) will be measured
Brain activity	change from baseline to week 8	measured with functional magnetic resonance imaging (fMRI)

Trial Locations

Locations (1)

King's College London; 🇬🇧 London, United Kingdom