GUT MICROBIOTA AND DEPRESSION: MECHANISMS, EVIDENCE, AND IMPLICATIONS FOR TREATMENT AND SPORT: A CURRENT REVIEW

Bartosz Wiśniewski; Dominika Pachnowska; Kacper Cholewiński; Natalia Badowska; Izabela Matuszek; Natalia Pluta; Katarzyna Aleksandra Nowak; Alicja Rutkowska-Nowosielska; Oliwia Nikola Czekanow; Jerzy Demkow; Zofia Kania-Bonicka

doi:10.31435/ijitss.2(50).2026.5674

Authors

Bartosz Wiśniewski Medical University of Warsaw, Warsaw, Poland https://orcid.org/0009-0004-1025-5573
Dominika Pachnowska Medical University of Warsaw, Warsaw, Poland https://orcid.org/0009-0000-6326-655X
Kacper Cholewiński Medical University of Warsaw, Warsaw, Poland https://orcid.org/0009-0004-7185-5310
Natalia Badowska Medical University of Warsaw, Warsaw, Poland https://orcid.org/0009-0003-9767-334X
Izabela Matuszek Medical University of Warsaw, Warsaw, Poland https://orcid.org/0009-0008-4002-2868
Natalia Pluta Medical University of Warsaw, Warsaw, Poland https://orcid.org/0009-0006-9108-8993
Katarzyna Aleksandra Nowak Medical University of Warsaw, Warsaw, Poland https://orcid.org/0009-0002-2324-3219
Alicja Rutkowska-Nowosielska Medical University of Warsaw, Warsaw, Poland https://orcid.org/0009-0008-4018-7179
Oliwia Nikola Czekanow Medical University of Warsaw, Warsaw, Poland https://orcid.org/0009-0008-4813-7862
Jerzy Demkow Medical University of Warsaw, Warsaw, Poland https://orcid.org/0009-0009-8637-9181
Zofia Kania-Bonicka Medical University of Warsaw, Warsaw, Poland https://orcid.org/0009-0007-5511-133X

DOI:

https://doi.org/10.31435/ijitss.2(50).2026.5674

Keywords:

Gut Microbiota, Major Depressive Disorder, Microbiota-Gut-Brain Axis, Probiotics, Dysbiosis, Short-Chain Fatty Acids, Physical Activity

Abstract

Background: Major depressive disorder (MDD) affects over 264 million people globally. Growing evidence implicates the Microbiota-Gut-Brain axis in its pathogenesis, yet mechanisms and therapeutic implications remain incompletely understood.

Aim: To synthesise evidence on gut microbiota alterations in MDD, neurobiological mechanisms, microbiota-targeted interventions, and implications for sport populations.

Material and methods: A narrative review of 28 peer-reviewed publications (2019-2025) using PubMed. Search terms included gut microbiota, major depressive disorder, dysbiosis, probiotics, HPA axis, and short-chain fatty acids.

Results: Depletion of SCFA-producing genera – particularly Faecalibacterium, Coprococcus, and Prevotellaceae – alongside enrichment of pro-inflammatory taxa was identified across multiple systematic reviews. Three neurobiological pathways were delineated: serotonergic and GABAergic dysregulation, HPA axis dysfunction via the kynurenine pathway, and LPS-mediated neuroinflammation. Adjunctive probiotic supplementation demonstrated a modest antidepressant effect (SMD = 0.83). Moderate physical activity increases SCFA-producing taxa overlapping with those depleted in MDD.

Conclusions: Gut microbiota alterations are associated with MDD through identifiable pathways. Probiotics show adjunctive therapeutic potential. Sport populations represent a clinically relevant group for microbiota-targeted research.

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