Parkinson’s disease and the gut

A theory was proposed more than 10 years ago that “the seeds of Parkinson’s disease somehow climb out of the gut and into the brain.”  In particular, “a misfolded form of a protein known as alpha-synuclein ” may play a vital role.  In this clumpy state, the protein “may damage and kill neurons including those near the base of the brain that help control movement” leading to the tremors and body rigidity of Parkinson’s disease.

A new study found that the appendix “holds immune cells that may help coordinate the [human] gut’s response to pathogens, and bacteria that may help maintain a healthy balance of gut microbes.”  That’s positive.  However, the appendix–even in healthy people–also has a supply of alpha-synuclein.  The theory is that the misfolded, clumpy form of this protein can spread from the appendix to the brain.

The new study tracked the medical records of 1.7 million Swedish citizens since 1964.  From that analysis, there is a “1% chance that a person will develop Parkinson’s after age 65.”  But, in this very large sample, the people who had their appendix removed 20 or more years in the past had a 20% lower risk of developing Parkinson’s, especially those who lived in rural areas-meaning there may also be an environmental link to Parkinson’s (possibly pesticide exposure).

What does this all mean?

No, you should not have your appendix removed thinking it will prevent you from getting Parkinson’s.

Yes, there may well be a causal tie between the human gut (the microbiome) and the development of Parkinson’s disease.  Research teams around the world are focusing on this connection.

Read the article (Kelly Servick, Science, October 31, 2018).

For more information about the gut and the microbiome, search the Science Primary Literature Database and the Headline Science Database.