Evidence for Parkinson ' s Disease to Have a Bacterial Origin
This study aimed to investigate whether Desulfovibrio bacteria induce alpha-syn aggregation. Fecal samples of ten PD patients and their healthy spouses were collected for molecular detection of Desulfovibrio species, followed by bacterial isolation. Isolated Desulfovibrio strains were used as diets to feed Caenorhabditis elegans nematodes which overexpress human alpha-syn fused with yellow fluorescence protein. Curli-producing Escherichia coli MC4100, which has been shown to facilitate alpha-syn aggregation in animal models, was used as a control bacterial strain, and E. coli LSR11, incapable of producing curli, was used as another control strain. The head sections of the worms were imaged using confocal microscopy. We also performed survival assay to determine the effect of Desulfovibrio bacteria on the survival of the nematodes. Statistical analysis revealed that worms fed Desulfovibrio bacteria from PD patients harbored significantly more and larger alpha-syn aggregates than worms fed Desulfovibrio bacteria from healthy individuals or worms fed E. coli strains. In addition, during similar follow-up time, worms fed Desulfovibrio strains from PD patients died in significantly higher quantities than worms fed E. coli LSR11 bacteria. These results suggest that Desulfovibrio bacteria contribute to PD development by inducing alpha-syn aggregation.