A new observational study led by researchers at University College London suggests that changes in the gut microbiome may provide an early indication of Parkinson’s disease risk, potentially years before clinical symptoms appear. Published in Nature Medicine on 20 April, the peer-reviewed study analysed microbial patterns in the digestive systems of individuals with Parkinson’s disease, those genetically predisposed to the condition, and healthy controls. The findings indicate that specific microbial signatures may serve as early biomarkers, opening avenues for earlier detection and preventative strategies.
Parkinson’s disease, a progressive neurodegenerative disorder, is recognised as one of the leading causes of disability worldwide and continues to rise in prevalence. Against this backdrop, the identification of pre-symptomatic indicators is considered a critical step towards improving patient outcomes.
Professor Anthony Schapira, lead investigator of the study, emphasised the urgency of such developments: “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. “To enable both the research and eventual use of such treatments, we need to develop the means for very early detection of people who will, or likely will, go on to develop the disease.
The international research team examined clinical and faecal samples from 271 individuals with Parkinson’s disease, 43 asymptomatic carriers of the GBA1 gene variant, and 150 healthy participants. The GBA1 variant is known to increase the risk of Parkinson’s disease significantly. Analysis revealed that 176 microbial species – more than a quarter of the gut microbiome – differed in abundance between Parkinson’s patients and healthy individuals. Notably, 142 of these species also differed between healthy participants and those carrying the GBA1 variant, despite the latter group showing no symptoms.
The microbiome profile of genetically at-risk individuals appeared to sit between that of healthy controls and diagnosed patients, suggesting a transitional microbial state linked to disease development.
Professor Schapira noted: “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. Importantly, these same changes can be found in a small proportion of the general population that may put them at increased risk for Parkinson’s.
“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.”
The findings were further validated using additional cohorts from the UK, Korea and Turkey, strengthening the robustness of the observed associations.
While further research is needed, the study underscores the growing importance of the gut–brain axis in neurodegenerative disease and highlights the potential of microbiome-based diagnostics and interventions in Parkinson’s disease.
By Rosie Bannister