Identification of bidirectional causal links between gut microbiota and narcolepsy type 1 using Mendelian...

Area of Science:

• Neuroscience
• Microbiology
• Genetics

Background:

• Narcolepsy type 1 (NT1) is a rare neurological disorder linked to orexin deficiency and cataplexy.
• The relationship between NT1 and gut microbiota is suspected but not fully understood.

Purpose of the Study:

• To investigate the causal relationship between gut microbiota composition and narcolepsy type 1 (NT1) using a bidirectional Mendelian randomization approach.

Main Methods:

• Utilized large-scale genetic data from the MiBioGen and FinnGen consortia.
• Employed the inverse-variance weighted (IVW) method for primary analysis, supported by multiple sensitivity analyses.

Main Results:

• Identified specific gut bacterial genera associated with altered NT1 risk, including Blautia (decreased risk) and Alloprevotella (increased risk).
• Observed bidirectional effects, where NT1 onset may influence gut microbial composition, such as a decrease in Eubacterium eligens group.
• Findings were consistent across various sensitivity analyses, confirming robustness.

Conclusions:

• Established robust evidence for bidirectional causal links between specific gut microbial taxa and NT1.
• Highlighted the critical role of the microbiota-gut-brain axis in the pathophysiology of narcolepsy type 1.