MICROBIOTA-GUT-BRAIN AXIS IN MAJOR DEPRESSION: PATHOPHYSIOLOGY AND PSYCHOBIOTIC INTERVENTIONS

Jan Pietrzak; Dominika Błonka; Aleksandra Jaskulska; Magda Skudzińska; Karolina Wołk; Janina Pohrybieniuk; Filip Kochański; Maria Irena Grys; Magdalena Bartold; Kamil Rajczyk

doi:10.31435/ijitss.1(49).2026.4809

Authors

Jan Pietrzak Clinic of Foundation "Swoboda", Głowno, Poland https://orcid.org/0009-0005-4177-5413
Dominika Błonka Centralny Szpital Kliniczny, Łódź, Poland https://orcid.org/0009-0005-7946-9294
Aleksandra Jaskulska Medical University of Lodz, Łódź, Poland https://orcid.org/0009-0003-8745-9593
Magda Skudzińska Samodzielny Publiczny Zespół Zakładów Opieki Zdrowotnej w Wyszkowie, Wyszków, Poland https://orcid.org/0009-0006-8747-2562
Karolina Wołk Pabianice Medical Center, Pabianice, Poland https://orcid.org/0009-0001-9871-4903
Janina Pohrybieniuk Faculty of Medicine, Wroclaw Medical University, Wrocław, Poland https://orcid.org/0000-0002-5737-6880
Filip Kochański Maria Skłodowska-Curie Specialist Hospital in Zgierz, Zgierz, Poland https://orcid.org/0009-0007-4957-8566
Maria Irena Grys Karol Jonscher Municipal Medical Centre in Łódź, Łódź, Poland https://orcid.org/0009-0009-9182-4040
Magdalena Bartold Maria Skłodowska-Curie Specialist Hospital in Zgierz, Zgierz, Poland https://orcid.org/0009-0005-0863-167X
Kamil Rajczyk Poznan University of Medical Sciences, Poznań, Poland https://orcid.org/0009-0002-3603-0706

DOI:

https://doi.org/10.31435/ijitss.1(49).2026.4809

Keywords:

Microbiota-Gut-Brain Axis, Psychobiotics, Depression, Gut Microbiota

Abstract

Introduction: The microbiota-gut-brain (MGB) axis is a complex network of interactions between the gastrointestinal tract and central nervous system. Increasing numbers of evidence indicates that its dysregulation may be implicated in contributing to the pathophysiology of depression. Changes in gut microbial profile, gut permeability, immune activation and microbial metabolite generation (especially short-chain fatty acids and neurotransmitter precursors) seem to impact neuroinflammatory pathway modulation and neurotransmission, with effect on mood and behavior.

Aim of the Study: To identify the most effective treatments for the regulation, modulation, and management of the MGB axis in depressive disease, and to summarize available evidence for the potential treatment of depression via microbiota-mediated modulation, such as probiotics, prebiotics, dietary modification, and fecal microbiota transplantation.

Materials and Methods: This paper reviews the literature in the PubMed database, and applies the following keywords: “microbiota-gut-brain axis”, “gut-brain axis”, “psychobiotics”, “depression”, “gut microbiota”, ”vagus nerve signaling”, “fecal microbiota transplantation”.

Conclusions: There are evidences for a central role of the MGB axis in depression along immune, metabolic and neural circuits. According to preclinical and emerging clinical evidence, modulation of gut microbiota (i.e., psychobiotics, prebiotics, high fiber diets, and fermented foods) can restore microbial balance, maintain barrier function, reduce neuroinflammation, and ameliorate neurogenesis, thereby attenuating depressive behaviors. However, heterogeneity in experimental designs, strains, and populations highlights the importance of establishing standardized guidelines and conducting large-scale randomized trials for microbiome-based therapies.

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