Microbiota–gut–brain axis and anxiety or depression: bibliometric and visual analysis
This bibliometric study maps publication trends on the MGB axis and mental disorders but provides no efficacy data for any clinical intervention.
| Population | Scientific literature indexed in the Web of Science Core Collection on the MGB axis and anxiety or depression |
|---|---|
| Intervention | Bibliometric analysis using CiteSpace and VOSviewer (co-citation, co-occurrence, collaborative networks, keyword burst detection) |
| Comparator | — |
| Outcome | Annual publication volume; Geographic distribution of publications; Author productivity; Institutional productivity; Predominant keywords (co-occurrence) |
Summary of findings
| Outcome | Effect | 95% CI | Certainty | Clinical relevance | Notes |
|---|---|---|---|---|---|
| Annual publication volume | descriptive count: 1816 articles, continuous annual increase (no statistical test reported) | — | Very low | — | 1 studies |
| Geographic distribution of publications | descriptive: China 497/1816 articles (27.37%) | — | Very low | — | 1 studies |
| Author productivity | descriptive: Cryan JF top author, 115 publications | — | Very low | — | 1 studies |
| Institutional productivity | descriptive: University College Cork 138/1816 articles (7.60%) | — | Very low | — | 1 studies |
| Predominant keywords (co-occurrence) | descriptive: probiotics and inflammation as top co-occurring keywords (no quantitative effect size reported) | — | Very low | — | 1 studies |
Context
Anxiety and depression affect hundreds of millions of people worldwide. The microbiota–gut–brain axis is an increasingly investigated pathophysiological pathway. Mapping the volume, actors, and dominant themes in the literature guides future research priorities.
What the study showed
A total of 1816 articles were identified, with a continuous annual upward trend. China led with 497 publications (27.37% of the total). The journal Nutrients concentrated 77 articles (4.24%). John F. Cryan was the most prolific author (115 publications) and University College Cork the most productive institution (138 articles; 7.60%). Probiotics and inflammation were the most prominent keywords.
How it was done
Bibliometric review of articles retrieved from the Web of Science Core Collection with no explicitly stated time restriction. CiteSpace and VOSviewer were applied for co-citation network analysis, keyword co-occurrence, and country and institutional collaboration. No PICO-based study selection or clinical data extraction was performed.
Effect magnitude
Not applicable: the study measures no clinical effect of any intervention. Data are descriptive of bibliographic volume and collaboration networks.
Risk of bias
Single data source (Web of Science), excluding Scopus, PubMed, and other databases, which underestimates total production. No standardized risk-of-bias tool (RoB 2, ROBINS-I, or AMSTAR-2) was applied. Bibliometric analysis provides no information on methodological quality, replicability, or clinical validity of included studies.
What this study does NOT prove
This study does not prove that any MGB axis intervention reduces anxiety or depression. It establishes no causality, efficacy, safety, or clinical applicability of any therapeutic approach.
In clinical practice
This study provides NO basis for changing clinical practice. It maps the research landscape, not treatment efficacy. Clinicians should consult systematic reviews and RCTs for therapeutic decisions regarding probiotics or MGB axis interventions.
Limitations
Single data source (Web of Science), excluding Scopus, PubMed, and other databases, which underestimates total production. No standardized risk-of-bias tool (RoB 2, ROBINS-I, or AMSTAR-2) was applied. Bibliometric analysis provides no information on methodological quality, replicability, or clinical validity of included studies.
What is still missing
Systematic reviews and meta-analyses of RCTs with standardized clinical outcomes (validated anxiety and depression scales) are needed to translate bibliographic volume into actionable recommendations.
Technical appendix
Version history
- 1.0 · 2026-06-21 — Auto-generated under Evidence Standard v1.0