A new study provides the most compelling evidence yet that Parkinson's disease begins in the gut and not the brain, reports New Atlas. If borne out, the findings could lead to preventative treatments that detect flawed proteins in the gut then cut off their path to the brain before they can cause bigger trouble. The idea that Parkinson's begins in the gut is a controversial one first proposed in 2003. The new study in Neuron, out of Johns Hopkins University, lends weight to it by showing that the proteins at fault can indeed travel up to the brain in animals—in this case, mice—through the vagus nerve. When scientists injected the proteins into the stomach of mice, the animals began exhibiting symptoms of Parksinson's roughly a month later, reports the Scientist.
"It supports and really provides the first experimental evidence that Parkinson’s disease can start in the gut and go up the vagus nerve," study co-author Ted Dawson tells the Guardian, which notes the team also injected the proteins into the stomachs of mice with severed vagus nerves. Parkinson's patients have a buildup of a "misfolded protein," alpha-synuclein, in their brains, explains a release at Eureka Alert, and no such misfolded proteins were detected in the brains of that second group of mice. The protein clumps wreak havoc, causing brain cells to die and impeding patients' ability to move and think. The idea behind the new research is that if these abnormal proteins are found in the gut before they start traveling, Parkinson's can be slowed or even stopped. (People who had their appendix removed were less likely to develop Parkinson's.)