Evidence of a Link Between Gut Bacteria and Parkinson Disease Manifestations

To examine the effect of gut microbiota on the manifestations of Parkinson disease (PD), researchers used mice designed to overexpress alpha synuclein, the protein that deposits into the guts and brains of PD patients, and examined the effects of partial and total microbiome depletion in these alpha synuclein overexpression (ASO) mice compared with the effects in wild-type animals (without ASO).

ASO mice had motor deficits compared with wild-type mice, but in germ-free conditions these deficits were reduced or disappeared. Gut bacteria also activated microglia in ASO mice, raising the possibility of neuroinflammation. When ASO animals with only partially depleted microbiomes received antibiotics to fully deplete the microbiome, the animals' …