Antibiotics and antifungals may slightly affect Parkinson’s risk, study finds

A Rutgers Health study found that people who took several penicillin-based antibiotics had a modestly lower risk of developing Parkinson’s disease, a surprising finding that researchers say highlights the complex relationship between the bacteria in the digestive tract and health. of the brain.

The study, published in Parkinsonism and related disordersanalyzed medical records of more than 93,000 people in the United Kingdom. The researchers found that those who received five or more courses of penicillin-based antibiotics in the five years before diagnosis had about a 15% lower risk of developing Parkinson’s compared with those who took no antibiotics.

“We found an inverse dose-response relationship between the number of courses of penicillin and the risk of Parkinson’s disease over several time periods,” said Gian Pal, a neurologist at Rutgers Robert Wood Johnson Medical School and lead author of the study. “This was unexpected and contrasts with some previous studies.”

The findings add to growing evidence that the trillions of microbes that live in the human digestive tract may play a role in Parkinson’s disease, a progressive brain disorder that affects movement and balance. Some researchers believe that inflammation or toxins from certain gut bacteria may contribute to the development of the disease.

“There is an idea that the disease starts in the gut and that inflammation in the gut can make it more permeable and allow toxins or inflammation to travel up to the brain via the vagus nerve,” Pal said.

To investigate possible links between gut bacteria and Parkinson’s, researchers examined anonymized medical records from a large UK database. They compared 12,557 people diagnosed with Parkinson’s to 80,804 similar individuals without the disease.

In addition to the reduced risk associated with penicillin use, the study found that people who took two or more courses of antifungal medications in the five years before diagnosis had about a 16 percent increased risk of developing Parkinson’s. This is in line with the findings of a previous Finnish study.

However, Pal said the associations were relatively small and should not influence medical decisions.

“This is all very mild, so it shouldn’t influence decisions about when to use antibiotics or antifungals,” he said. “The importance of the study is that it demonstrates the idea that something happening in the gut microbiome can influence Parkinson’s disease,”

The study has limitations, such as the inability to take into account other behaviors that affect bacteria, such as the patient’s diet.

Still, Pal said the findings support further investigation into how gut microbes may influence Parkinson’s risk.

“The fact that a drug that you take for just a few days changes your microbiome a little bit changes your risk of Parkinson’s — to me, that strengthens the argument that the microbiome is implicated,” he said.

Parkinson’s disease affects more than 10 million people worldwide and cases are expected to increase as the population ages. Although its exact causes remain unclear, researchers believe that a combination of genetic and environmental factors produces the disease. It is diagnosed primarily based on symptoms as there is no definitive laboratory test.

Pal said the study’s follow-up research includes investigating whether specific fungi or bacteria in the gut are associated with Parkinson’s risk.

“Better understand what the antifungal composition is in the intestine – that hasn’t really been explored well – and seeing if this is useful in distinguishing Parkinson’s patients from non-Parkinson’s patients would be helpful,” he said.

Researchers also hope to determine whether altering the levels of certain gut microbes could potentially reduce the risk of Parkinson’s or modify the course of the disease in those already diagnosed.