Bifidobacterium plantarum and Reduced Depression Symptoms

Research synthesisLow evidenceModerate effect3 studies · 3 beneficial · 0 neutral · 0 harmful

Across 3 studies, all reported beneficial effects of Bifidobacterium plantarum interventions on reduced depression symptoms, with moderate effect sizes. Two of the three studies found statistically significant results, including a meta-analysis (SMD -0.55, p=0.03) and a review reporting significant reductions on the HAM-D scale. Evidence is predominantly from systematic reviews and meta-analyses of multi-species probiotic formulations in adults and adolescents with or without mood disturbances; dose ranges and study durations were not consistently reported.

Studied populations: adults with or without mood disturbances, adolescents with depression

Caveats: All three studies are 2025 reviews or meta-analyses, but two are systematic/scoping reviews with limited detail on individual trial quality; only 3 total papers were identified for this specific pair. Multi-species formulations were used, making it difficult to isolate the effect of Bifidobacterium plantarum alone. Dose and duration data were not reported in the available studies.

Generated May 11, 2026

3 of 3 papers

Efficacy of Lactobacillus spp. Interventions to Modulate Mood Symptoms: A Scoping Review of Clinical Trials.
- 2025-08-21
- Systematic Review
- International journal of molecular sciences 26(16)
- - Diego Fernández-Rodríguez
  - María Consuelo Bravo
  - Marcela Pizarro
  - Pablo Vergara-Barra
  - María José Hormazábal
  - Marcell Leonario-Rodriguez
- PubMed: 40869419
- DOI: 10.3390/ijms26168099
6 Insights on
- Reduced Depression Symptoms
- High evidence
- Rigorous Journal
Multi-species formulations yielded reductions in depressive symptoms and changes in neurobiological markers.
Effect
Beneficial
Effect size
Moderate
Role of Probiotics in Management of Depressive Symptoms and Cognitive Impairment in Patients With Depression: An Updated Analysis of Trials.
- 2025-11-29
- Meta-Analysis
- Brain and behavior 15(12)
- - Syed Ali Arsal
  - Aashish Kumar
  - Umer Iqbal
  - Shafin Bin Amin
  - Muhammad Aniq Amir
  - Muhammad Abrar Amir
  - Muhammad Ashir Shafique
  - Suhaib Ahmed
  - Laksh Kumar
  - Oluwatobiloba Israel Popoola
  - Inibehe Ime Okon
- PubMed: 41319022
- DOI: 10.1002/brb3.71108
2 Insights on
- Reduced Depression Symptoms
- High evidence
the probiotic group had a significant reduction in depressive symptoms compared to the placebo group (p = 0.03; SMD, -0.55; 95% CI, -1.04 to -0.06; I2 = 79%)
Effect
Beneficial
Effect size
Moderate
Significant
Yes
Gut-brain axis in adolescent depression: a systematic review of psychological implications and behavioral interventions.
- 2025-09-04
- Review
- Frontiers in nutrition 12
- - Haitao Liu
  - Xiaoli Li
  - Ying Shi
  - Ke Hong
  - Xing Wang
  - Congfu Huang
- PubMed: 40977983
- DOI: 10.3389/fnut.2025.1644245
2 Insights on
- Reduced Depression Symptoms
- Low evidence
Psychobiotics (e.g., Lactobacillus plantarum PS128) significantly reduced depressive symptoms (HAM-D Δ = -4.2; 95% CI: -5.1, -3.3) vs. placebo and improved emotion recognition (+18%; 95% CI: 2.1, 33.9).
Effect
Beneficial
Effect size
Moderate
Significant
Yes

Bifidobacterium plantarum and Reduced Depression Symptoms

Efficacy of Lactobacillus spp. Interventions to Modulate Mood Symptoms: A Scoping Review of Clinical Trials.

Role of Probiotics in Management of Depressive Symptoms and Cognitive Impairment in Patients With Depression: An Updated Analysis of Trials.

Gut-brain axis in adolescent depression: a systematic review of psychological implications and behavioral interventions.