By Janelle Miles, ABC News
Illustration of Lewy bodies in neurons (nerve cells). Lewy bodies are accumulations of proteins that develop inside nerve cells in Parkinson's disease and Lewy body dementia (LBD). File image. Photo: EMES LASZLO/SCIENCE PHOTO LIBRA / NLA / Science Photo Library via AFP
Australian researchers are working on developing drugs that target bugs in the guts of Parkinson's disease patients in a radical new treatment approach they hope will slow or even stop the progression of the debilitating illness.
Queensland University of Technology neuroscientist Richard Gordon said the research followed emerging evidence suggesting the gut was as important as the brain in the development of Parkinson's.
Associate professor Gordon, based at the Translational Research Institute in Brisbane, said studies showed differences in the complex gut ecosystems of Parkinson's disease patients compared with healthy people.
He said people with Parkinson's disease were known to experience persistent inflammation and activation of the immune system, believed to be closely linked to an imbalance of microbes in their guts.
"The inflammation, over a prolonged period, has been shown to damage the vulnerable dopamine-producing neurons that are gradually lost in people with Parkinson's," Gordon said.
Rise in cases linked to 'chemical exposure'
Parkinson's disease is a progressive movement disorder, characterised by degeneration of dopamine-producing neurons in the brain.
The decrease in dopamine levels results in impaired mobility - including tremors, stiffness of the arms and legs, slow movement, and poor balance.
Other symptoms can include an impaired sense of smell, disturbed sleep, anxiety and depression, fatigue, gut problems, and speech changes.
Drug treatments, such as levodopa, which increases the amount of dopamine in the brain, help alleviate some patients' symptoms rather than slow the progression of the illness.
In what he described as "a radical new way of thinking" about Parkinson's disease, Gordon's team has been awarded $4 million (NZD4.3m) over four years by the US Department of Defense to work on new therapeutics targeting the gut microbiome.
He said military personnel were considered at increased risk of developing neurological conditions, such as Parkinson's disease, because of chemical exposures during their service.
"There is this rapid increase in the prevalence of Parkinson's globally," Gordon said.
"We believe it's linked to … chemical exposures."
The gut is a new target
The Queensland research will involve both human and animal studies to identify new classes of therapeutics to treat Parkinson's disease, first described more than 200 years ago by London doctor, James Parkinson.
Scientists will study blood, urine, and faecal samples from at least 70 Parkinson's patients and compare them to those of similarly aged healthy volunteers.
"One of the ways we study the gut microbiome is by sequencing the bacteria that's present in people's guts," Gordon said.
They hope to be able to identify so-called "healthy bugs" that may disappear in people with Parkinson's.
"Then we're going to use that knowledge to develop drugs, or improve the drugs that we have, to target the microbes rather than just target the brain, which we've done in the past," Gordon said.
'Bugs as drugs'
In what he termed a "bugs as drugs" approach, he said the team would also engineer bacteria and test their potential to slow or stop Parkinson's progression by altering the gut ecosystem.
"These studies would be done in animals initially," he said.
"Once we know that it's safe and it's effective the next phase of this work will take that towards clinical trials."
The research team includes scientists from QUT's School of Biomedical Sciences and neurologists from the Royal Brisbane and Women's and Princess Alexandra hospitals.
They will partner with researchers at the University of Georgia in the US.
An estimated 200,000 Australians have Parkinson's disease.
- ABC