Changes in a person’s gut bacteria could be an early warning sign of Parkinson’s disease, scientists have found.
Each person has a unique set of gut microbes, including bacteria, fungi and viruses that live in the digestive tract. But people with Parkinson’s disease have a distinct make up of gut microbes and so do healthy people with a genetic risk of the disease, according to a study by University College London (UCL) researchers.
The findings could help develop tests to reveal if someone is at risk of Parkinson’s disease and may also lead to new ways to prevent Parkinson’s by targeting the gut.
Professor Anthony Schapira, lead investigator of the study, said: “Parkinson’s disease is a major cause of disability worldwide, and the fastest growing neurodegenerative disease in terms of prevalence and mortality. There is an urgent need to develop treatments that can stop or slow the disease’s progression.
“In recent years there has been a growing recognition of the links between Parkinson’s disease – a brain disorder – and gut health. Here we have strengthened that evidence and shown that microbes in the gut can reveal signs of Parkinson’s and may be an early warning signal of Parkinson’s risk years before symptom onset.”
Scientists have previously found a link between bacteria in the mouth and gut and the progression of cognitive decline in Parkinson’s disease, which affects about 166,000 people in the UK. This includes the shift from mild memory issues to dementia, a common and distressing symptom of the disease, researchers at King’s College London found.
For this new study, published in the journal Nature Medicine, researchers analysed data from 271 people with Parkinson’s disease, 43 carriers of the GBA1 variant (a gene variant that can increase the risk of Parkinson’s disease by up to 30-fold) with no clinical symptoms, and 150 healthy participants.
Findings showed more than a quarter of the microbes making up the gut microbiome differed when comparing people with Parkinson’s disease to healthy participants – it was most noticeable among people in more advanced stages of Parkinson’s.
A difference in microbes was also seen when comparing healthy participants to people with the GBA1 gene variant, who have not yet experienced any symptoms of Parkinson’s disease.
Professor Schapira added: “For the first time we identify bacteria in the gut of people with Parkinson’s that can also be found in those with a genetic risk for the disease, but before they develop symptoms.
“This discovery opens the way not only to see if the bacteria are a way to identify those at risk of Parkinson’s, but also to see if changing the bacterial population, through dietary changes or medication, can reduce a person’s risk for Parkinson’s.”
Study participants also provided data about their dietary habits, which revealed some evidence that those with a more balanced and varied diet are less likely to have gut microbiomes that suggest an elevated risk of Parkinson’s.
But more research is still needed to understand what other genetic or environmental factors are at play to determine whether someone develops Parkinson’s disease.
