If C.diff bacteria are a culprit in PD as the following quote suggests,
"He recently received funding to carry out a clinical trial using anti-C. difficile antibiotics to treat 18 cases of Parkinson's — an idea that occurred to him after observing that patients with chronic constipation and Parkinson's who received fecal transplants experienced a marked decrease in their neurological symptoms"
Read more: Same poop, different gut - The Scientist - Magazine of the Life Sciences
http://www.the-scientist.com/news/di...#ixzz1ypbc3900
then some lab rat out there might try Florastor or another brand of saccharomyces boulardii yeast, known to combat C.difficile.
http://www.crohnsforum.com/showthread.php?t=15293
http://en.wikipedia.org/wiki/Saccharomyces_boulardii