Gut bacteria can help predict the risk of developing Parkinson's disease

BarcelonaFor a long time we have known that we could not live without the trillions of bacteria we have in our gut, as they are responsible for essential physiological functions, but in recent decades the scientific community has taken a step further and has linked this intestinal microbiota with the brain. For example, studies have discovered that people with neurodegenerative diseases such as Alzheimer's or Parkinson's have alterations in the composition of intestinal bacteria, although it is not yet known whether it is a cause or consequence of the disease. Now researchers at University College of London have discovered in a study that the microbiota can reveal if a person has a high risk of developing Parkinson's disease before symptoms appear.

Parkinson's patients and healthy individuals with a genetic risk of developing the disease have a specific composition of intestinal microorganisms, according to the conclusions of the research published this Monday in the journal Nature Medicine. "We have shown that intestinal microorganisms can reveal signs of Parkinson's and act as an early warning signal years before the onset of symptoms," assures the lead researcher of the investigation, Anthony Schapira. The results pave the way for the development of tests that can detect those at risk of developing the disease and recommend preventive measures (as there is no cure available) especially through diet, to delay the onset of symptoms.

A total of 464 people from the United Kingdom and Italy participated in the study, of whom 271 had Parkinson's, 43 had a genetic predisposition, and 150 had no predisposition. The researchers analyzed the alterations in the participants' microbiota from fecal samples and identified a pattern among people with the disease: the presence of certain groups of gut bacteria decreases or increases depending on the stage of Parkinson's. Patients in more advanced stages had microbiota alterations 15 times greater than those in early stages.

Regarding individuals with a genetic predisposition but without the disease, they also observed similar, albeit less pronounced, alterations. "This discovery opens the door not only to using these bacteria to identify individuals at risk of developing Parkinson's but also to exploring whether modifying the bacterial population, either through dietary changes or medication, can reduce the risk of the disease," says Schapira. The scientists corroborated the results by comparing them with data from patients who did not participate in the study from the United Kingdom, Korea, and Turkey, which included 638 individuals with Parkinson's and 319 healthy participants.

Dietary habits

Now, a small proportion of healthy participants without a genetic predisposition also presented gut microbiomes similar to those of people at risk of Parkinson's, leading researchers to wonder if they might also be at risk of developing the disease. In any case, they emphasize that more research is still needed to understand what genetic or environmental factors determine whether a person will eventually develop the disease or not.

In this regard, participants also provided data on their dietary habits, and the study's conclusions suggest that those with a more balanced and varied diet are less likely to have a microbiota associated with developing Parkinson's. According to the researchers, this could indicate that modifying diet may play a key role in preventing the disease, but they insist that research must continue.