Parkinsons Disease and gut viruses

The incidence of Parkinsons Disease (PD) is on the rise in the western world, specially among white men.

PD is a disease that affects movement and is due to loss of dopaminergic (dopamine producing) neurons in the substantia nigra and the striatum as well as characteristic neuronal changes such as accumulation of Lewy bodies and Alpha-synuclein.  Although genetic factors contribute up to development of PD, its believed that up to 90% of all cases are environmentally caused.  Its known that pesticides contribute to this but now its the role of the gut microbes and the viruses that kill them!

The idea that gut microbiome is playing a role in pathogenesis of Parkinsons Disease (PD) is gaining momentum.   A study in 2016 started this shift in direction in terms of the cause(s) of PD when a study showed that partial vagus nerve resection caused improvements in PD symptoms.  Since this find, some focus has gone into the role of vagus nerve, how it is effected by the Enteric Nervous System (ENS), and the gut microbes.  ENS is the nerve meshwork that innervates the layers of the gut from the mouth to the other end of the tube.

As more and more studies confirm the role of gut microbiome in formation of PD, a researcher looked at what is killing the beneficial bacteria if the diet is good and there is plenty of probiotics in a persons daily meal.  It turns out that the environment may alter the ratio of good bacteria, such as lactococcus in the gut by killing them off with a bacteriophage that attacks and kills those bacteria.  Lactococcus and Lactococcus destroying bacteriophages are the first one to be looked at but its yielding lots of interesting results and pointing to new directions.

Because some of those characteristic neuronal changes are seen in the ENS and the results of vagus nerve resection, it is assumed that the pathology is sent from the gut up to the brain thru the nerves.  I have a different theory.  I think the bacteria secrete molecules, their metabolic waste products, and those molecules making it into the blood and thru to the brain are somehow protecting these super sensitive dopaminergic neurons in the striatum and when that microbiome is disrupted, that protection is gone and after a few years, symptoms develop preceded by Lewy bodies and alpha-synuclein in the ENS.

Whatever the true mechanisms will turn out to be, all results point to the importance of the right balance of beneficial bacteria in the gut, and according to this new study, the ratio of bacteria to bacteriophage which kills the bacteria!