Deep nasal sinus cavity microbiota dysbiosis in Parkinson's disease
Pal et al./Nature/2021
Why It Matters
This paper caught my attention because it connects two early PD markers: smell loss and nasal inflammation. The finding that certain bacteria near the olfactory bulb correlate with symptom severity supports the idea that neurodegeneration might start in the nose before reaching the brain. If this holds up, nasal microbiome testing could become an early screening tool, and targeting these bacteria might slow progression—though that's speculative at this stage.
Key Findings
- PD patients showed significantly different bacterial communities in deep nasal cavities compared to both spousal and non-spousal healthy controls, with increased abundance of Moraxella catarrhalis
- PD patients' nasal microbiota was more similar to their spouses than to unrelated controls, suggesting shared environmental factors influence the microbiome independent of disease
- Higher levels of M. catarrhalis correlated with more severe motor symptom scores in PD patients, suggesting a potential link between this bacterium and disease progression
- The altered microbiome in PD was characterized by potentially pro-inflammatory bacterial species near the olfactory bulb, supporting the hypothesis that nasal inflammation could trigger neurodegeneration
- Study used 16S rRNA gene sequencing to characterize bacterial communities specifically from the deep nasal sinus cavity—closer to the olfactory bulb than typical nasal swabs