Exploring the link between Parkinson’s disease and gut health

The impact of our gut bacteria on our overall health is an area of science that is generating a lot of interest. While it may seem unlikely that something in our gut can influence physiological processes in the brain, there is increasing evidence to show that it is possible.

IPAN PhD student Nathan Nuzum is specifically investigating the relationship between gut bacteria and Parkinson’s disease.

He says not only is it likely that there is a relationship, but that this connection between our gut bacteria and brain may be modifiable through lifestyle factors like diet.

What we know about our gut bacteria and Parkinson’s disease so far

Nathan’s systematic review on gut bacteria and Parkinson’s disease found in nine of the 13 included studies that gut bacteria capable of producing a particular short chain fatty acid, butyrate, were less abundant in the Parkinson’s groups compared to the groups without Parkinson’s.

Nathan said this difference in butyrate-producing bacteria is relevant because of the health promoting functions of butyrate, including maintaining the health of our intestinal walls and providing anti-inflammatory actions within the immune system.

“Importantly, both a reduction in butyrate, meaning a lack of anti-inflammatory compounds, and a compromised intestinal wall may further perpetuate the pathological processes involved in Parkinson’s disease,” he said.

What role might diet play in this pathway?

While it is important to show how gut bacteria might differ between people with and without Parkinson’s, it is also important to consider the reasons for these differences.

Nathan said that despite diet having been shown to alter the composition of our gut bacteria, this factor was not well investigated in the included studies.

“We know our diet contributes greatly to our gut bacteria composition and variations in diet have the capacity to alter gut microbiome. However, most people’s gut microbiomes remain relatively stable through adulthood, potentially because they do not undergo drastic shifts in dietary patterns,” he said.

But what impact might our dietary choices have on the different types of bacteria in our gut and the compounds that they produce?

“It has been shown that a diet higher in fibre helps the beneficial bacteria in our gut grow,” Nathan explained.

“These bacteria feed on the indigestible fibre and are then able to produce beneficial compounds, like the short chain fatty acid butyrate, mentioned above.

“Due to the positive impact indigestible fibre has on our gut bacteria it is classed as a ‘pre-biotic’, as it promotes the growth of beneficial gut bacteria.”

The potentially important ways in which our gut bacteria may be related to Parkinson’s disease opens the door for further study to understand the role of our gut and its bacteria in this condition.

“Ultimately, there is the potential for earlier diagnoses and additional therapeutic treatment options,” Nathan said.

 

Nathan Nuzum is a PhD student supervised by Dr Helen Macpherson at the Institute for Physical Activity and Nutrition (IPAN), Deakin University.