A friend of mine's daughter gets severe mental problems resembling a bipolar condition from gluten. She is generally all right when she is able to avoid gluten in her diet but sometimes she accidentally gets some. There is a probiotic called HMF Neuro that supposedly breaks down the exorphins formed in the gut before they can get absorbed so she is now trying it.

I intend to try some myself as another experiment to see if it affects PD. I read that MJF went to Bhutan and his symptoms ameliorated. There was some speculation that it was the lack of gluten in the diet there that might have provided the benefit.