Gut microbiome may predict Parkinson's risk years before symptoms appear

Microorganisms in the human gut can signal the risk of developing Parkinson’s disease years before the onset of the first symptoms, according to a new study reported by Euronews.

Scientists from University College London (UCL) have found that people with the disease, as well as those with a genetic predisposition, possess specific patterns of gut bacteria.

“In recent years, there has been a growing understanding of the link between Parkinson’s disease—a brain disorder—and gut health,” says Anthony Schapira, lead researcher from UCL. He adds that the results reinforce evidence that the gut microbiome can serve as an early warning signal for the risk of the disease.

The study, published in the journal Nature Medicine, involved the analysis of clinical and fecal samples from participants in the UK and Italy.

Participants included:

• 271 people with Parkinson’s disease
• 43 carriers of the GBA1 variant (a gene that increases risk up to 30 times) but without symptoms
• 150 healthy control participants

The results show that more than a quarter of the microbial species in the gut microbiome differ between sick and healthy individuals. Certain bacteria are more common in Parkinson’s patients, while others predominate in healthy individuals.

These differences are most pronounced in people at a more advanced stage of the disease, but they are also observed in asymptomatic carriers of the GBA1 genetic variant.

“Importantly, the same changes are found in a small portion of the general population, which may indicate an increased risk of developing Parkinson’s,” Schapira emphasizes.

Parkinson’s disease is the fastest-growing neurodegenerative disorder in terms of prevalence, disability, and mortality, and the second most common after Alzheimer’s disease.

The disease is characterized by the gradual loss of dopamine-producing neurons. By the time motor symptoms appear and a diagnosis is made, more than half of these cells have already died.

Researchers emphasize that early detection is crucial for the effectiveness of future therapies.

“Analysis of the gut microbiome could allow us to identify individuals at risk and offer them ways to reduce that risk, for example, through dietary changes,” says co-author Stanislav Dusko Ehrlich.

However, scientists note that further research is needed to clarify what other genetic and environmental factors influence whether a person will actually develop the disease.