In the course of long-term experiments on animals, a group of scientists from Johns Hopkins University (USA) found that the main cause of Parkinson's disease may be proteins that are misfolded in the intestine, which then enter the brain.
Parkinson's disease is characterized by the progressive death of neurons responsible for the production of dopamine ("the hormone of joy"). According to scientists, this occurs as a result of the aggregation of misfolded clusters of the protein alpha-synuclein, which are called Lewy bodies.
For the first time this hypothesis was put forward by the German scientist Heiko Braak in the early 2000s, but there was no exact confirmation of it. In 2014, as a result of experiments on rats at J. Hopkins University, it was possible to establish that Levy's bodies actually spread from the intestine to the brain and cause pathological signs of Parkinson's disease.
At the beginning of the research, scientists injected synthetic misfolded alpha-synuclein into the intestines of healthy mice, after which they monitored the condition of the animals for 10 months. The analysis showed that alpha-synuclein first aggregates at the junction of the vagus nerve with the intestine, and then spreads through the brain. It is also noteworthy that the movement of alpha-synuclein proteins into the brain was stopped when the vagus nerve ruptured.
Bottom line: Research results indicate that Parkinson's disease can occur in the gut, and blocking its pathway prevents the development of this dangerous disease.