Elsevier

Brain, Behavior, and Immunity

Volume 48, August 2015, Pages 186-194
Brain, Behavior, and Immunity

Altered fecal microbiota composition in patients with major depressive disorder

https://doi.org/10.1016/j.bbi.2015.03.016Get rights and content
Under a Creative Commons license
open access

Highlights

  • An altered fecal microbiota composition was found in patients with depression.

  • Enterobacteriaceae and Alistipes were over-represented in patients with depression.

  • A negative correlation was found between Faecalibacterium and depressive symptoms.

Abstract

Studies using animal models have shown that depression affects the stability of the microbiota, but the actual structure and composition in patients with major depressive disorder (MDD) are not well understood. Here, we analyzed fecal samples from 46 patients with depression (29 active-MDD and 17 responded-MDD) and 30 healthy controls (HCs). High-throughput pyrosequencing showed that, according to the Shannon index, increased fecal bacterial α-diversity was found in the active-MDD (A-MDD) vs. the HC group but not in the responded-MDD (R-MDD) vs. the HC group. Bacteroidetes, Proteobacteria, and Actinobacteria strongly increased in level, whereas that of Firmicutes was significantly reduced in the A-MDD and R-MDD groups compared with the HC group. Despite profound interindividual variability, levels of several predominant genera were significantly different between the MDD and HC groups. Most notably, the MDD groups had increased levels of Enterobacteriaceae and Alistipes but reduced levels of Faecalibacterium. A negative correlation was observed between Faecalibacterium and the severity of depressive symptoms. These findings enable a better understanding of changes in the fecal microbiota composition in such patients, showing either a predominance of some potentially harmful bacterial groups or a reduction in beneficial bacterial genera. Further studies are warranted to elucidate the temporal and causal relationships between gut microbiota and depression and to evaluate the suitability of the microbiome as a biomarker.

Abbreviations

BDNF
brain-derived neurotrophic factor
DSM-IV
the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition
HCs
healthy controls
HPA
hypothalamic–pituitary–adrenal
IL-6
interleukin-6
IL-1β
interleukin-1 beta
HAMDS
Hamilton’s Depression Scale
MADRS
Montgomery–Asberg Depression Rating Scale
MDD
major depression disorder
TNF-α
tumor necrosis alpha

Keywords

Depression
Gut bacteria
Inflammation
Gut–brain
Antidepressant

Cited by (0)

1

These authors contributed equally to this work.

2

Co-corresponding author. Tel.: +86 571 8723 6585; fax: +86 571 8723 6459.