Correspondence to Author: Antonio Costanzo MD, Valentina Rampulla MD, Maria Vittoria Mannucci MD, Antonella Nisi MD, Valentina Fischetti MD, Martina Sala MD, Emanuele Fulco MD, Passannanti Daniele MD, Varricchio Antonio MD. 

1. Antonio Costanzo, MD, General and Emergency Surgery, Asst Bergamo est Ospedale Bolognini di Seriate (BG), Italy. Email: [email protected]. Corresponding author.
2. Valentina Rampulla, MD, General and Oncological Surgery Asst Bergamo Ovest Ospedale di Treviglio-Caravaggio (BG), Italy. Email: [email protected]
3. Maria Vittoria Mannucci, MD, Post-Graduate School of General Surgery, Università degli Studi di Milano La Statale, Milan, Italy. Email: [email protected]
4. Antonella Nisi, MD, Post-Graduate School of General Surgery, Università degli Studi di Milano La Statale, Milan, Italy. Email: [email protected]
5. Valentina Fischetti, MD, Post-Graduate School of General Surgery, Università degli Studi di Milano La Statale, Milan, Italy. Email: [email protected]

6. Martina Sala, MD, Post-Graduate School of General Surgery, Università degli Studi di Milano La Statale, Milan, Italy. Email: [email protected].
7. Emanuele Fulco, MD, Post-Graduate School of General Surgery, Università degli Studi di Milano La Statale, Milan, Italy. Email: [email protected]
8. Daniele Passannanti, MD, General and Emergency Surgery, Asst Bergamo est Ospedale Bolognini di Seriate (BG), Italy. Email: [email protected]
9. Antonio Varricchio MD, AORN San Pio di Benevento (Bn), Italy. Email: [email protected].

DOI: 10.52338/jjogastro.2025.5289

Abstract:

Depressive syndrome is a leading cause of disability worldwide, with complex pathophysiology involving genetic, environmental, and neurobiological factors. Recent evidence highlights the gut microbiota as a key modulator of brain function through the microbiota–gut–brain axis. This narrative review synthesizes recent literature on the relationship between gut microbiota and depressive syndrome, focusing on neurotransmitter modulation, and therapeutic implications. Dysbiosis has been consistently associated with alterations in serotonin, GABA (gamma-aminobutyric acid), dopamine, norepinephrine, glutamate, and short chain fatty acid pathways. Clinical studies and meta analyses suggest that probiotics, prebiotics, and dietary interventions may reduce depressive symptoms. While promising, current evidence is limited by heterogeneity and small sample sizes. Future research should prioritize standardized clinical trials and personalized microbiome based strategies

Keywords: Gut microbiota; Depression; Neurotransmitters; Psychobiotics; Gut–brain axis.

Citation:

Dr.Antonio Costanzo MD, The Influence of Gut Microbiota on Depressive Syndrome: A Narrative Review.Japanese Journal of Gastroenterology 2026.