For years we’ve been assuming – for good reason – that the cause behind Parkinson’s disease is all in the brain. But recently scientists have been taking a more profound approach to the condition, with some now claiming that its root cause may in fact be found in the gut.
Presenting their research at the annual American Society for Microbiology meeting this week, scientists have revealed a potential link not only between gut flora and Parkinson’s but also the potential role that viruses might play in influencing the microbiome. If proven, this could lead to a novel treatment for the disease that involves antiviral drugs.
The team from the Human Microbiology Institute in New York looked at the diversity of bacteria found in the guts of 32 patients diagnosed with Parkinson’s disease and compared it to the microbiome of 28 healthy patients. Curiously, they found that there was a much higher number of viruses that target the gut's microorganisms, known as bacteriophages, in those with the long-term neurodegenerative disorder.
Crucially, the researchers found that there was an increase in the phages that target and get rid of the Lactococcus group of bacteria. The impact of these viruses could clearly be seen, as patients with Parkinson’s had 10 times less Lactococcus in their guts. Interestingly, these bacteria are known to play a role in producing dopamine, a neurotransmitter implicated in the disease. The team could rule out the impact that Parkinson’s medication may have had, as all those taking part in the study were doing so before being prescribed medication.
The researchers, therefore, suggest that the higher levels of the virus may have caused a decrease in the bacteria, which had a knock-on effect on the nerves that link the gut and the brain. This chain reaction could potentially have impacted the development of Parkinson’s disease.
While this notion is a compelling one – particularly as our understanding of the microbiome and the role it plays in disease has changed radically over the last decade – the suggestion from this research is far from conclusive. For example, it might be that the Parkinson’s medication is not to blame for the changes in gut flora, but that the nerve damage comes first followed by the alteration of the bacteria.
Whatever the case may be, this study does hint at the intriguing role our gut may play in our mental health, and will certainly be of intense focus for far more research in the future.