Could the Bacteria in your stomach cause Parkinson’s disease?

What is Parkinson’s disease and how does it affect you?

Parkinson’s disease is the second most common neurodegenerative condition (which means the destruction of nerve and brain cells) in the world. It causes your body to shake (the medical community call this tremors) and bradykinesia (which means slow movement). Doctors looking at movement call this ‘motor function’. Parkinson’s affects the brain by decreasing the amount of Dopamine available. Dopamine is one of the chemicals that your brain needs for its cells to communicate with each other. Cells that produce dopamine die in those with Parkinson’s disease. Another problem that Parkinson’s disease can cause, it the creation of ‘Lewy bodies’. These are abnormal protein deposits that can block cells in the brain from communicating with each other

A neuron located in the brain. Parkinson’s Disease can cause Lewy Bodies to deposit in these cells – these are shown in red


The cause of Parkinson’s is thought to be genetic based, however in reality, most cases are caused by something in our environment. The environmental cause of Parkinson’s has been hard to locate, however research has shown that it more than likely begins in the stomach.
Often an early symptom of Parkinson’s begins with stomach issues like over salivating, constipation, feeling sick and incontinence which then develops into motor issues causing problems with walking and tremors.
This study looked into a specific type of pathogenic bacteria called Helicobacter Pylori. This bacteria has chronically infected half of the world population and can lead to stomach ulcers and cancer.

How could H. Pylori cause Parkinson’s disease?

This authors in this study came up with 4 possible ideas for how H. Pylori could cause Parkinson’s:

  1. Toxins produced by the bacteria
  2. Disturbing the delicate balance of bacteria in your gut
  3. Inflammation in the gut that crosses into the brain (via the gut-brain axis – as your brain can influence your gut and your gut can influence your brain)
  4. Manipulation of how drugs move around your body. H. Pylori could affect how Levodopa (a chemical that can be turned into Dopamine) is absorbed by the body

What did they discover?

The key findings were:

  1. People who have Parkinson’s disease are 1.5 to 3 times more likely to be infected with H. Pylori than those who don’t have the disease
  2. Parkinson’s patients who are infected with H. Pylori are show worse motor functions than those who aren’t infected
  3. Removing H. Pylori from infected Parkinson’s patients improved their motor function over those who didn’t get their H. Pylori removed
  4. Removing H. Pylori improved Levodopa absorption in Parkinson’s patients compared to those who didn’t have it removed

This article has shown that there is clearly a link between your stomach and Parkinson’s disease, particularly if you are infected with the stomach dwelling H. Pylori bacteria. The mechanisms that these bacteria take to cause or contribute to Parkinson’s disease is still unclear and more research needs to be done focusing on the H. Pylori toxins, inflammation, Levodopa absorption and the carefully regulated bacterial balance in your gut.



Journal: Journal of Parkinson’s Disease, Volume 8, Issue 3, 14 May 2018

Author: David J. McGeea, Xiao-Hong Lub and Elizabeth A. Disbrowb

Copyright: Open Access