A systematic review on gut-brain axis aberrations in bipolar disorder and methods of balancing the gut microbiota

Crystal Obi-Azuike; Ruona Ebiai; Taneil Gibson; Ariana Hernandez; Asma Khan; Gibson Anugwom; Alexsandra Urhi; Sakshi Prasad; Sara Ait Souabni; Funso Oladunjoye

doi:10.1002/brb3.3037

A systematic review on gut-brain axis aberrations in bipolar disorder and methods of balancing the gut microbiota

Brain Behav. 2023 Jun;13(6):e3037. doi: 10.1002/brb3.3037. Epub 2023 May 1.

Authors

Affiliations

¹ Department of Psychiatry and Behavioral Sciences, Tulane University School of Medicine, New Orleans, Los Angeles, USA.
² Department of Internal Medicine, Ochsner Clinic Foundation, New Orleans, Louisiana, USA.
³ Department of Psychiatry, University of Medicine and Health Sciences (UMHS), New York, New York, USA.
⁴ Department of Psychiatry, Lake Erie College of Osteopathic Medicine, Erie, Pennsylvania, USA.
⁵ Menninger Department of Psychiatry & Behavioral Sciences, Baylor College of Medicine, Houston, Texas, USA.
⁶ Department of Mental Health, Federal Medical Center, Asaba, Delta State, Nigeria.
⁷ Department of Psychiatry, National Pirogov Memorial Medical University, Vinnytsya, Vinnytsya, Ukraine.
⁸ Faculty of Medicine and Pharmacy of Marrakesh, Cadi Ayyad University, -, Marrakech, Marrakech, Morocco.

Abstract

Background: Bipolar disorder (BD) is a mood disorder that affects millions worldwide. Up to half of the diagnosed patients are reported to not receive adequate treatment. This study aims to assess the relationship between the gut-brain axis and BD and to discuss and compare the efficacy of varying methods of balancing gut microbiotas in BD.

Methods: Using PubMed, Embase, and Google Scholar from November 2021 to February 2022, we found 5310 studies on gut microbiota and its relation to BD. Using our inclusion criteria, 5283 studies were excluded. A total of 27 full-text articles were assessed for eligibility. Also, 12 articles that met our criteria and eligibility criteria reported on 613 BD patients.

Results: Most studies analyzed found an overall difference in gut microbiota composition in bipolar patients compared to healthy controls, though the alterations found were not consistent. Differences in Lactobacillus, Faecalibacterium, and Ruminococcus abundance in BD compared to controls were found to be the most consistent across a few of the studies, but their effects on the gut-brain axis conflicted. Probiotic supplementation was found to lower patient rehospitalizations and significantly improve depressive symptoms and cognitive impairments among patients with BD.

Conclusions: Multiple studies included in this review point toward a possible link between BD and the gut microbiota. Probiotic supplements and other gut-balancing therapies could serve as effective adjunctive methods for the treatment of BD. Notable limitations of the studies included for analysis were small sample sizes and majority observational study designs. Furthermore, the microbiota aberrations found in patients with BD were not consistent across multiple studies. Despite these limitations, our findings demonstrate the need for further research regarding the relationship between aberrant gut microbiota profiles and BD, as well as the effectiveness of gut balancing methods as adjunctive treatments.

Keywords: biomarker; bipolar depression; bipolar disorder; gut microbiome; gut microbiota; mania; mood disorder; probiotic.

Publication types

Systematic Review
Review

MeSH terms

Bipolar Disorder* / diagnosis
Bipolar Disorder* / therapy
Brain-Gut Axis
Gastrointestinal Microbiome*
Humans
Observational Studies as Topic