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Published on: June 2, 2022
Relationships between the gut microbiome and brain functional alterations in first-episode, drug-naïve patients with
Dahai Wang1, Xiaowei Jiang2, Huaqian Zhu3
1Department of Psychiatry, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, PR China.
Objective:
Increasing evidence has shown that the microbiota-gut-brain axis (MGB) is involved in the mechanism of major depressive disorder (MDD). However, the relationship between the gut microbiome and brain function in MDD patients has not been determined. Here, we intend to identify specific changes in the gut microbiome and brain function in first-episode, drug-naïve MDD patients and then explore the associations between the two omics to elucidate how the MGB axis plays a role in MDD development.
Methods:
We recruited 38 first-episode, drug-naïve MDD patients and 37 healthy controls (HC). The composition of the fecal microbiome and neural spontaneous activity alterations were examined using 16S rRNA gene amplicon sequencing analysis and regional homogeneity (ReHo). Spearman correlation analyses were conducted to assess the associations between the gut microbiome and brain function.
Results:
Compared with HC, MDD patients exhibited distinct alterations in the gut microbiota and elevated ReHo in the frontal regions. In the MDD group, a positive relationship was noted between the relative abundance of Blautia and the HAMD-17 and HAMA scores, as well as between the relative abundance of Oxalobacteraceae and the HAMD-17 score. The relative abundances of Porphyromonadaceae and Parabacteroides were negatively correlated with the ReHo values of frontal regions.
Limitations:
Our study utilized a cross-sectional design, and the number of subjects was relatively small.
Conclusion:
We found that some specific gut microbiomes were associated with frontal function, and others were associated with clinical symptoms in MDD patients, which may support the role of the MGB axis underlying MDD.
Insights
Specific gut bacteria like Blautia and Oxalobacteraceae are linked to major depressive disorder (MDD) symptoms and brain activity. These findings highlight the microbiota-gut-brain axis
Area of Science:
- Neuroscience
- Microbiology
- Psychiatry
Background:
- The microbiota-gut-brain (MGB) axis is increasingly implicated in major depressive disorder (MDD) pathogenesis.
- The precise relationship between gut microbiome composition and brain function in MDD remains unclear.
Purpose of the Study:
- To identify specific alterations in the gut microbiome and brain function in first-episode, drug-naïve MDD patients.
- To explore associations between gut microbiome changes and brain activity in MDD.
Main Methods:
- 16S rRNA gene sequencing for fecal microbiome analysis.
- Regional homogeneity (ReHo) to assess neural spontaneous activity.
- Spearman correlation to link microbiome and brain function data in 38 MDD patients and 37 healthy controls.
Main Results:
- MDD patients showed distinct gut microbiota profiles and increased frontal ReHo compared to controls.
- Blautia abundance correlated positively with depression severity (HAMD-17, HAMA scores).
- Oxalobacteraceae abundance correlated positively with HAMD-17 scores, while Porphyromonadaceae and Parabacteroides abundances negatively correlated with frontal ReHo.
Conclusions:
- Specific gut bacteria are associated with frontal brain function and clinical symptoms in MDD.
- These findings support the role of the microbiota-gut-brain axis in the pathophysiology of MDD.
- Limitations include a cross-sectional design and a small sample size.
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