The gut microbiome and depression: a review

ABSTRACT

Background

Recent explorations into the gut microbiome of humans and animals reveal implications in chronic physical and mental health disorders. Relatively little is known regarding the relationship of gut microbiome and depression. In the current review, we reviewed existing scientific data related to the gut microbiome and healthy patients versus patients with depression. Additionally, scientific literature containing the utility of microbiome interventions to improve depression symptoms was reviewed.

Methods

A PubMed and Clinical Key literature search combined the key terms ‘gut,’ ‘microbiome,’ ‘bacteria,’ and ‘depression’ to identify studies investigating these relationships.

Results

76 relevant articles were identified. Human and animal studies reviewed examined marked alterations in the dominant bacterial phyla in the gut of individuals with depression, the connection between leaky gut and neuroinflammation in depression, brain regulatory centers impacted by changes in the gut microbiome, and the benefits of the addition of a probiotic/prebiotic for gut and mental health.

Conclusions

The current review confirmed the suspected direct communication between the gut microbiome, brain functioning, and depression. Additionally, studies suggest antibiotics disrupt the gut microbiome. There are important implications for psychiatrists in providing opportunities for intervention and enhancement of current treatments for individuals with depression.

KEYWORDS:

• depression
• gut health
• microbiome
• probiotic
• prebiotic
• antibiotic
• bacteria
• psychiatry
• cognition

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Clare Schrodt

Clare Schrodt is a fourth year medical student at Saint Louis University who has taken part in multiple research projects including several literature reviews ranging from pharmacology to microbiome studies, and she has also worked on a feasibility study concerning diet and patient attitudes. Her research interests include nutritional medicine and the socioeconomic outcomes of diet.

Anika Mahavni

Anika Mahavni is a third year medical student at Saint Louis University with research interests in preventive care and women’s health. This is her first medical journal publication, though she has presented posters at multiple conferences and published work in the field of ecology.

Griffin P.J. McNamara

Griffin P.J. McNamara is an M.D. candidate at Saint Louis University School of Medicine whose research focuses on improving patient outcomes with the use of interventional radiology procedures.

Morgan D. Tallman

Morgan D. Tallman is a psychometrist at Saint Louis University with research interests that include emotional factors and cognitive functions. This is her second scientific journal publication.

Bryanna T. Bruger

Bryanna T. Bruger is an instructor of neurology and a clinical neuropsychologist at Saint Louis University School of Medicine. Her research interests include psychiatric, neurologic, and neurocognitive disorders, trauma-related disorders, and sport psychology.

Lauren Schwarz

Lauren Schwarz is a Professor of Psychiatry and board-certified clinical neuropsychologist at Saint Louis University School of Medicine. She has previously published research in the area of neurocognitive disorders including dementia and cerebrovascular disease.