Longevity & AgingGut Microbe Streptococcus mutans Fuels Parkinson's Disease via Brain-Reaching Metabolite
Researchers identified that Streptococcus mutans, a bacterium typically found in the mouth but elevated in the gut microbiome of Parkinson's disease (PD) patients, produces imidazole propionate (ImP) via its enzyme urocanate reductase (UrdA). ImP was found at higher levels in PD patients' plasma. In germ-free mice colonized with S. mutans, ImP accumulated in both blood and brain, causing dopaminergic neuron loss, neuroinflammation (astrogliosis and microgliosis), and motor deficits resembling PD. Direct ImP administration alone reproduced these effects. The mTORC1 signaling pathway was identified as the key mechanistic driver. These findings establish a causal gut-brain axis link in PD through a specific microbial metabolite.
