Bifidobacterium bifidum Rosell-71 and Reduced Depression Symptoms

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

Across 3 studies, all reported beneficial moderate-sized effects of Bifidobacterium bifidum Rosell-71 (as part of probiotic blends) on reducing depressive symptoms. Two of three studies reported statistically significant findings, including a 2025 meta-analysis showing a significant reduction (p=0.03; SMD=-0.55). The most-studied dose and form were not consistently reported, and populations included adults with depression or general adult samples.

Studied populations: adults with depression (from meta-analysis of RCTs) and general adults

Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. Available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed). The studies did not isolate Bifidobacterium bifidum Rosell-71 specifically; effects are attributed to probiotic mixtures, making it difficult to attribute benefit to this single strain. Doses, forms, and durations were not consistently reported across studies.

Generated May 12, 2026

3 of 3 papers

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
Probiotics as Modulators of Adult Neurogenesis and Synaptic Plasticity: New Perspectives in the Pathophysiology and Treatment of Affective Disorders.
- 2026-03-12
- Review
- Biomedicines 14(3)
- - Gilberto Uriel Rosas-Sánchez
  - León Jesús Germán-Ponciano
  - María Isabel Pérez-Vega
  - Oscar Gutiérrez-Coronado
  - José Luis Muñoz-Carrillo
  - Alejandro David Soriano-Hernández
  - Abril Alondra Barrientos-Bonilla
  - Carmen Gabriela Rosales-Muñoz
  - Cesar Soria-Fregozo
- PubMed: 41898284
- DOI: 10.3390/biomedicines14030637
4 Insights on
- Reduced Depression Symptoms
- Low evidence
Clinical evidence from randomized controlled trials and recent meta-analyses indicates that probiotic supplementation produces significant reductions in depressive and anxiety symptoms
Effect
Beneficial
Effect size
Moderate
Significant
Yes
Probiotics' Effects in the Treatment of Anxiety and Depression: A Comprehensive Review of 2014-2023 Clinical Trials.
- 2024-02-19
- Review
- Microorganisms 12(2)
- - Ermis Merkouris
  - Theodora Mavroudi
  - Daniil Miliotas
  - Dimitrios Tsiptsios
  - Aspasia Serdari
  - Foteini Christidi
  - Triantafyllos K Doskas
  - Christoph Mueller
  - Konstantinos Tsamakis
- PubMed: 38399815
- DOI: 10.3390/microorganisms12020411
2 Insights on
- Reduced Depression Symptoms
- Low evidence
the majority of the most recent literature suggests a beneficial role of probiotics in the treatment of depression and anxiety
Effect
Beneficial
Effect size
Moderate

Bifidobacterium bifidum Rosell-71 and Reduced Depression Symptoms

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

Probiotics as Modulators of Adult Neurogenesis and Synaptic Plasticity: New Perspectives in the Pathophysiology and Treatment of Affective Disorders.

Probiotics' Effects in the Treatment of Anxiety and Depression: A Comprehensive Review of 2014-2023 Clinical Trials.