Evidence map›Paper›PMID 40790243›Full record

SynthesisBMC nutrition2025

Impact of probiotic supplementation on serum levels of brain-derived neurotrophic factor: GRADE-based dose-response meta-analysis.

Reza Hashemi, Mohammad M Hussein M Raouf, Tanya S Salih, Marzieh Feyzpour, Maryam Eskandarioun, Najmeh Nezamabadipour, Hossein Gandomkar

Abstract readSystematic Review
In one paragraph

Synthesis in BMC nutrition, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers.

0numbers the graph read from it
0cells of the map it votes in
5citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

5 citing papers in PubMed.

  1. Review
  2. Review
  3. Review
  4. Review
  5. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Reza HashemiDepartment of Pharmacy, College of Pharmacy, Knowledge university, Erbil 44001, Iraq.
Mohammad M Hussein M RaoufDepartment of Biomedical Sciences, College of Applied Science, Cihan University-Erbil, Erbil, Kurdistan Region, Iraq.
Tanya S SalihDepartment of Medical Microbiology, College of Applied Science, Cihan University-Erbil, Erbil, Kurdistan Region, Iraq.
Marzieh FeyzpourFaculty of Medical Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Maryam EskandariounSchool of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran.
Najmeh NezamabadipourSchool of Medicine, Bam University of Medical Sciences, Bam, Iran. nutiran.research@gmail.com.
Hossein GandomkarDepartment of surgical oncology, Tehran University of Medical Medicine, Tehran, Iran. gandomkar.hossein@gmail.com.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundBrain-derived neurotrophic factor (BDNF) is a key neurotrophin involved in neuroplasticity and cognitive function, with its dysregulation linked to neurodegenerative and psychiatric disorders. Probiotics, through the gut-brain axis, may modulate BDNF levels, but evidence remains inconsistent. This meta-analysis aimed to evaluate the effect of probiotic supplementation on serum BDNF levels and explore dose-response relationships.

methodsWe conducted a systematic review and meta-analysis, searching PubMed, Scopus, Cochrane Central, Web of Science, and Embase up to April 2025, following PRISMA guidelines (PROSPERO: CRD420251036851). Randomized controlled trials (RCTs) involving adults (≥ 18 years) with a minimum 2-week probiotic intervention and reported BDNF levels were included. A random-effects model calculated weighted mean differences (WMDs), and fractional polynomial modeling assessed non-linear dose-response relationships. Heterogeneity, publication bias, and evidence quality (GRADE) were evaluated.

resultsFrom 20 RCTs (n = 2372 participants), probiotic supplementation significantly increased serum BDNF levels (WMD = 0.18, 95% CI: 0.11–0.26; P < 0.001), with high heterogeneity (I²=96%, P < 0.001). Subgroup analysis identified longer follow-up duration (> 10 weeks) as a heterogeneity source (WMD = 1.69, 95% CI: 1.13–2.26; I²=46%). A significant non-linear association was found between treatment duration and BDNF levels (Pnonlinearity = 0.02), but not dosage (Pnonlinearity = 0.277). No significant publication bias was detected (Begg’s P = 0.15; Egger’s P = 0.29). Evidence quality was very low per GRADE.

conclusionsProbiotic supplementation increases serum BDNF levels, particularly with prolonged interventions (> 10 weeks), suggesting its potential as an adjunctive therapy for BDNF-related disorders, warranting further high-quality research. CLINICAL TRIAL NUMBER: Not applicable.

Indexed as

Brain-derived neurotrophic factorGut-brain axisMeta-analysisProbiotic

Identifiers

PMID40790243
PMCPMC12337545

What Socratic holds

Textmetadata
LicenceCC BY-NC-ND
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.