Prebiotics and probiotics for depression and anxiety: A systematic review and meta-analysis of controlled clinical trials.
Liu RT, Walsh RFL, Sheehan AE.
Neuroscience & Biobehavioral Reviews · 2019:13-23
This study evaluates Prebiotic supplements (fiber compounds that feed gut bacteria) or probiotic supplements (live beneficial bacteria strains) in various doses and combinations, compared with placebo or control in relation to Change in depression and anxiety symptom scores on standard questionnaires.
Evidence-Based Research: Probiotics Depression Gut Brain Nature
Key facts at a glance
- DOI
- 10.1016/j.neubiorev.2019.03.023
- PMID
- 31004628
- PMC
- PMC6584030
- Journal
- Neuroscience & Biobehavioral Reviews
- Year
- 2019
- Pages
- 13-23
- Study type
- meta-analysis
- Evidence level
- Ia
- Sample size
- 1931
- Intervention
- Prebiotic supplements (fiber compounds that feed gut bacteria) or probiotic supplements (live beneficial bacteria strains) in various doses and combinations, compared with placebo or control
- Primary outcome
- Change in depression and anxiety symptom scores on standard questionnaires
- Follow-up
- Typically 4–8 weeks (varied by trial)
- Funding
- unknown
- Effect size
- Probiotics for depression: SMD -0.24 (95% CI -0.36 to -0.12); probiotics for anxiety: SMD -0.12 (95% CI -0.24 to -0.01); prebiotics: no significant effect
- Open access
- false
Study Overview
This study examined the effects of Prebiotic supplements (fiber compounds that feed gut bacteria) or probiotic supplements (live beneficial bacteria strains) in various doses and combinations, compared with placebo or control on Change in depression and anxiety symptom scores on standard questionnaires.
Key Findings
The results suggest the intervention has potential clinical benefits.
Clinical Conclusions
See original publication.
Abstract
"This meta-analysis enrolled 1,931 participants, investigating the effects of Prebiotic supplements (fiber compounds that feed gut bacteria) or probiotic supplements (live beneficial bacteria strains) in various doses and combinations, compared with placebo or control on Change in depression and anxiety symptom scores on standard questionnaires.
Funding & conflicts of interest
Funding: unknown
COI: None reported
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Medically reviewed by WellAlly Editorial Team Last reviewed July 22, 2026. · Read our editorial policy