Gut microbiota, circulating cytokines and dementia: a Mendelian randomization study

Area of Science:

• Neuroscience
• Microbiology
• Genetics

Background:

• Emerging evidence suggests a link between gut microbiota and dementia.
• Causal relationships and the role of cytokines as mediators remain unclear.

Purpose of the Study:

• To investigate the causal effects of gut microbiota on five dementia types.
• To examine the role of cytokines in the gut microbiota-dementia pathway.

Main Methods:

• Utilized Mendelian randomization (MR) with genome-wide association studies (GWAS) summary data.
• Analyzed gut microbiota, cytokines, and Alzheimer's disease (AD), frontotemporal dementia (FTD), dementia with Lewy body (DLB), vascular dementia (VD), and Parkinson's disease dementia (PDD).
• Employed inverse variance weighting (IVW) for primary analysis.

Main Results:

• Identified numerous causal effects between gut microbiota and dementia.
• Found causal associations between cytokines and various dementias.
• Evidence indicated cytokines do not mediate the gut microbiota-dementia link.

Conclusions:

• Gut microbiota and cytokines exhibit causal associations with five dementia types.
• Cytokines do not appear to function as mediators in the gut microbiota-dementia pathway.