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SYSTEMATIC REVIEW article

Front. Nutr.
Sec. Nutrition, Psychology and Brain Health
Volume 11 - 2024 | doi: 10.3389/fnut.2024.1446854
This article is part of the Research Topic Effects of Probiotics, Prebiotics, and Postbiotics on Microbiota-Gut-Brain Axis View all 4 articles

From Gut to Brain: Unveiling Probiotic Effects Through a Neuroimaging perspective. A Systematic Review of Randomized Controlled Trials

Provisionally accepted
Annachiara Crocetta Annachiara Crocetta 1,2,3Donato Liloia Donato Liloia 1,2,3*Tommaso Costa Tommaso Costa 1,2,3,4Sergio Duca Sergio Duca 3Franco Cauda Franco Cauda 1,2,3,4Jordi Manuello Jordi Manuello 1,2,3
  • 1 University of Turin, Turin, Italy
  • 2 Functional Neuroimaging and Complex Neural Systems (FOCUS) Laboratory, Department of Psychology, University of Turin, Turin, Piedmont, Italy
  • 3 Koelliker Hospital and Nursing Home, Turin, Piedmont, Italy
  • 4 National Institute of Neuroscience, University of Turin, Torino, Italy

The final, formatted version of the article will be published soon.

    The gut-brain axis, a bidirectional communication network between the gastrointestinal system and the brain, significantly influences mental health and behavior. Probiotics, live microorganisms conferring health benefits, have garnered attention for their potential to modulate this axis. However, their effects on brain function through gut microbiota modulation remain controversial. This systematic review examines the effects of probiotics on brain activity and functioning, focusing on randomized controlled trials using both resting-state and task-based functional magnetic resonance imaging (fMRI) methodologies. Studies investigating probiotic effects on brain activity in healthy individuals and clinical populations (i.e., major depressive disorder and irritable bowel syndrome) were identified. In healthy individuals, task-based fMRI studies indicated that probiotics modulate brain activity related to emotional regulation and cognitive processing, particularly in high-order areas such as the amygdala, precuneus, and orbitofrontal cortex. Resting-state fMRI studies revealed changes in connectivity patterns, such as increased activation in the Salience Network and reduced activity in the Default Mode Network. In clinical populations, task-based fMRI studies showed that probiotics could normalize brain function in patients with major depressive disorder and irritable bowel syndrome. Resting-state fMRI studies further suggested improved connectivity in mood-regulating networks, specifically in the subcallosal cortex, amygdala and hippocampus. Despite promising findings, methodological variability and limited sample sizes emphasize the need for rigorous, longitudinal research to clarify the beneficial effects of probiotics on the gut-brain axis and mental health.

    Keywords: Probiotics, gut-brain axis, fMRI, Neuroimaging, Gut Microbiota, Depression, IBS

    Received: 10 Jun 2024; Accepted: 02 Sep 2024.

    Copyright: © 2024 Crocetta, Liloia, Costa, Duca, Cauda and Manuello. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Donato Liloia, University of Turin, Turin, Italy

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.