Exploring Causal Relationships Between Gut Microbiota and Alzheimer's Disease: A Bidirectional Mendelian
Anqi Chen1, Yuquan Wang1, Yue-Qing Hu1,2
1State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China.
Journal of Alzheimer'S Disease Reports
|August 8, 2024
Summary
This study used Mendelian randomization to investigate the causal link between gut microbiota and Alzheimer's disease (AD). Certain gut bacteria were found to increase AD risk, while others may offer protection.
Area of Science:
- Microbiome research
- Neurodegenerative disease genetics
- Human health and disease
Background:
- Observational studies suggest a link between gut microbiota and Alzheimer's disease (AD), but causality remains unproven.
- Understanding the gut-brain axis is crucial for AD pathogenesis.
- Existing research highlights the need for causal evidence in the gut microbiota-AD relationship.
Purpose of the Study:
- To establish a causal relationship between specific gut microbiota and Alzheimer's disease (AD) risk.
- To utilize Mendelian randomization (MR) to infer causality from observational data.
- To identify specific bacterial taxa that influence AD development.
Main Methods:
- A two-sample Mendelian randomization (MR) study design was employed.
- Genome-wide association study (GWAS) summary statistics for AD (85,934 cases, 401,577 controls) and gut microbiota (MiBioGen consortium) were utilized.
- Inverse variance weighting (IVW) and sensitivity analyses were performed to assess causality and rule out pleiotropy.
Main Results:
- Seven gut microbiota taxa showed a causal association with AD risk.
- Order *Selenomonadales*, Family *Pasteurellaceae*, and Genus *Methanobrevibacter* were associated with increased AD risk.
- Class *Mollicutes*, Genus *Ruminiclostridium9*, Genus *Clostridiuminnocuumgroup*, and Genus *Eggerthella* were associated with a reduced risk of AD.
Conclusions:
- This study provides causal evidence for the role of specific gut microbiota in Alzheimer's disease (AD).
- Findings suggest potential therapeutic targets within the gut microbiome for AD prevention or treatment.
- The gut-brain axis represents a promising avenue for future AD research and clinical interventions.
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