Coincidently I've been on antibiotics for the past week:
1x500mg, Flucloxacillin four times a day;
2x250mg, Penicillin V, four times a day.
(I'm taking them to help fight a foot infection.) The last week has been one of my best PD-wise for months: looser, more lively, better balance (but, still bad tremor).

My side-to-side tap test scores, at least 12 hours after my last dose of levodopa (but still benefitting from the controlled release agonist) have averaged about 36, as opposed to my normal 30.
( The results come from:
http://www.parkinsonsmeasurement.org...eToSideTap.htm
The figures given are the sum of left hand and right hand movements, with each measured over 30 sec.)

I find it difficult to reconcile the reports of reduced symptoms following antibiotic treatment with the idea that a major part of the aetiology of PD is the death of dopaminergic neurons: if they were dead, how can the antibiotic lead to more dopamine?

It seems to me to fit a continuous assault theory better: bacteria in the gut produce toxins which get through to the brain, where for some time before the dopaminergic cells die, they reduce the amount of dopamine produced. Here, by killing bacteria, the antibiotic reduces the amount of toxin being produced, leading to better dopamine production.

When my course of antibiotics is over I intend to take large amounts (about a litre per day) of homemade probiotic yogurt, in order to replenish some of the damage done by the antibiotics.

John