Not Yet RecruitingNot Applicable

PB-18 Probiotic for Mild to Moderate Depression

88 participantsStarted 2026-05-05

Plain-language summary

The goal of this clinical trial is to learn if Bifidobacterium PB-18 can treat mild to moderate depressive disorder in adults aged 18 to 65 years who are not taking antidepressants or other psychotropic medications during the study. It will also learn about the safety of Bifidobacterium PB-18 and explore its potential effects on the gut-brain axis. The main questions it aims to answer are: Does Bifidobacterium PB-18 increase the response rate at Week 8, defined as a reduction of at least 50% from baseline in the 17-item Hamilton Depression Rating Scale (HAMD-17)? What adverse events occur in participants receiving Bifidobacterium PB-18? How do gut microbiota, metabolite profiles, and related biological markers change after treatment with Bifidobacterium PB-18? Researchers will compare Bifidobacterium PB-18 with a placebo, a look-alike powder that does not contain PB-18, to see if Bifidobacterium PB-18 improves depressive symptoms. Participants will: Be randomly assigned to receive Bifidobacterium PB-18 or placebo in a 1:1 ratio Take the assigned study product once daily for 8 weeks Visit the study site at baseline, Week 4, and Week 8 for symptom and safety assessments Complete study questionnaires, including HAMD-17, HAMA, PSQI, and CBCT Provide blood and stool samples at baseline and Week 8 for exploratory biological analyses

Who can participate

Age range18 Years – 65 Years

SexALL

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AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Outpatient or inpatient participants, aged 18 to 65 years (inclusive), of any sex * Current episode meets Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria for depressive disorder * Baseline score on the 17-Item Hamilton Depression Rating Scale is 7 to 24, inclusive * No concomitant use of antidepressants or other psychotropic medications during the study * Elementary school education or above, able to understand the study requirements and complete the rating scales * Participant personally signs the informed consent form and is willing to complete follow-up according to the study protocol Exclusion Criteria: * Current or past diagnosis, according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria, of bipolar disorder, schizophrenia spectrum and other psychotic disorders, neurocognitive disorders, neurodevelopmental disorders, or substance-related and addictive disorders * Presence of significant psychotic symptoms, such as delusions or hallucinations * Severe or unstable diseases of the central nervous system, cardiovascular system, respiratory system, liver, kidneys, endocrine system, hematologic system, or other systems that, in the investigator's judgment, make the participant unsuitable for the study * Evident suicide risk, defined as a score of 1 or higher on the suicide item of the 17-Item Hamilton Depression Rating Scale * Active inflammatory disease * Gastrointestinal infection, tumor,…

What they're measuring

Response Rate at Week 8 Based on the 17-Item Hamilton Depression Rating Scale

Timeframe: Week 8

Trial details

NCT IDNCT07562516

SponsorFirst Affiliated Hospital of Zhejiang University

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2027-01-31

Contact for this trial

Jing Lu, PhD

15858200010 Lujing2016@zju.edu.cn