The bacteria living in your gut may offer early clues about long term health, possibly even before symptoms begin.
A new study published in Nature Medicine found that people with Parkinson’s disease have distinct patterns in their gut microbiome. Similar patterns also appeared in some people who are genetically at higher risk but have not yet developed symptoms, suggesting these changes may show up years before the disease becomes visible.
The research, led by scientists at University College London, adds to growing evidence that the gut and brain are closely connected, and that the microbiome may play a role in neurodegenerative disease.
“Parkinson’s disease is a major cause of disability worldwide, and the fastest growing neurodegenerative disease in terms of prevalence and mortality,” said lead investigator Professor Anthony Schapira. “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.”
Researchers analyzed stool samples and clinical data from more than 400 people, including those with Parkinson’s disease, healthy individuals and people carrying a gene variant linked to higher risk.
They found that 176 types of gut microbes differed in abundance between people with Parkinson’s and healthy participants. Many of these same differences also appeared in people with genetic risk but no symptoms.
The microbiome of these at risk individuals looked like a middle ground between healthy participants and those with Parkinson’s. That pattern suggests the microbiome may shift gradually over time.
The team also confirmed their findings in additional groups across multiple countries, strengthening confidence that the patterns were consistent.
“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,” Schapira said.
The study was not designed to test specific diets, but participants did report their eating habits. Researchers found some evidence that people with more varied, balanced diets were less likely to have microbiome patterns associated with elevated Parkinson’s risk.
That finding does not prove diet can prevent the disease. But it aligns with a broader body of research showing that dietary patterns help shape the gut microbiome in ways that may influence long term health.
Co lead author Professor Stanislav Dusko Ehrlich said this could eventually point to practical strategies.
“Gut microbiome analysis can enable us to identify individuals who are at risk of developing Parkinson’s disease, so that we can suggest ways for them to reduce their own risk, such as through dietary adjustments,” Ehrlich said.
This study is observational, which means it can identify patterns but cannot prove cause and effect. Researchers do not yet know whether microbiome changes contribute to Parkinson’s disease or reflect early biological changes already underway.
The study was supported by the Michael J. Fox Foundation for Parkinson’s Research and the Medical Research Council.