Lactobacillus Helveticus in the Treatment of Major Depression

Study Overview
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Brief Summary
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The main objective of the study is to evaluate whether the association of the probiotic Lactobacillus helveticus to standard antidepressant will contribute to the treatment of major depression.

Detailed Description
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Patients with the diagnosis of major depression according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria will receive one daily oral dose of 1 × 10^9 colony-forming units (CFUs) of Lactobacillus helveticus or placebo for 8 weeks in addition to conventional antidepressant treatment.

Official Title
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Double-blind Placebo-controlled Clinical Trial of Lactobacillus Helveticus as an add-on Strategy for the Treatment of Major Depression

Conditions
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Depression

Intervention / Treatment
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* Other: Probiotic
* Other: Maltodextrin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged between 18 and 65 years old; Diagnosis of major depression Agree to sign the informed consent. Exclusion Criteria: Treatment with anti-inflammatory drugs or antibiotics of any pharmacological classes in the month before treatment enrollment; Use of dietary supplementation (herbal supplements, other pro- or prebiotics).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Probiotic<br>Patients with major depression (both sexes) will receive capsules with 1 × 10^9 CFUs of Lactobacillus helveticus in addition to a conventional antidepressant treatment for 8 weeks. | Other: Probiotic<br>* Patients with major depression (both sexes) will receive capsules with 1 × 10^9 CFUs of Lactobacillus helveticus in addition to a conventional antidepressant treatment for 8 weeks.<br>|
| Placebo Comparator: Maltodextrin<br>Patients with major depression (both sexes) will receive capsules of placebo (maltodextrin) in addition to a conventional antidepressant treatment for 8 weeks | Other: Maltodextrin<br>* Patients with major depression (both sexes) will receive capsules of placebo (maltodextrin) in addition to a conventional antidepressant treatment for 8 weeks<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in the depressive symptoms severity | Depression symptoms severity will be assessed through the Montgomery-Asberg Depression Rating Scale (MADRS) (Minimum: 0 to 6 - normal/symptom absent/ Maximum: >34 - severe depression). Higher scores mean a worse outcome. | 8 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in microbiota composition | Microbiota composition will be assessed by Real-Time qPCR. | 8 weeks | 
| Changes in the serum levels of biomarkers | Inflammatory markers (adiponectin, resistin, leptin, TNF, IL6 and IL10) and neurotrophic factors (GDNF, NGF) will be assessed by enzyme-linked immunosorbent assay (ELISA). Markers will be measured in pg/ml. | 8 weeks | 
| Change in perception of stress | Perception of stress will be assessed by Perceived Stress Scale (PSS). It is a measure of the degree to which life situations are assessed as stressful. Range from 0 to 40 with higher scores indicating worse outcome. | 8 weeks |