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Could Bacteriophages Be the Cause of Parkinson’s Disease?

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Today, it may be obvious that genetic predisposition isn’t the only cause of human health and disease, and new research presented at ASM Microbe 2018 points to the particular part of the microbiome as possible drivers of Parkinson’s Disease (PD).

Previous research shows that PD, as well as many other neurodegenerative multifaceted pathologies, develops as an interplay of certain genetics and environmental factors.

“As of today, our research was actually the first to show that bacterial viruses are implicated in different human pathologies,” said Dr. George Tetz, a researcher at the Human Microbiology Institute in New York and lead author of the study. “We have absolutely come to believe that to understand human health, we need to look not only at the human genome, but also at bacterial viruses.”

For the study, the researchers examined the fecal microbiome of 32 patients with PD and 28 controls.

The researchers found that in patients with PD, the neurotransmitter producing Lactococcus spp. was almost 10 times lower compared to the control patients, due to the high numbers of Lactococcus phages.

As a result, researchers at the Human Microbiology Institute are understanding a “new world of microbiology,” says Tetz, where not only bacteria but bacteriophages affect our health.

The Road Less Traveled

As for why bacteriophages are only just being examined as human pathogens, Tetz says the answer is very straightforward.

“Bacteriophages were previously thought to selectively interact with bacterial cells, and not to affect eukaryotic cells,” he explained. Phages are generally suggested to be safe for humans; they are widely used as therapeutic agents for the treatment of different multi-resistant bacterial infections because they are universal “bacterial killers.”

On the other hand, bacteriophages have been suggested to be very important regulators of gut microbiota. In other words, different alterations of bacteriophages can lead to the certain alterations of gut bacteria.

“At the previous ASM 2017, we showed that bacteriophages could lead to the increased intestinal permeability,” said Tetz, who has published several other studies on the subject in scientific reports. “Here, the current work that was done in collaboration with our colleagues at New York University shows that patients with Parkinson’s Disease have an altered and decreased number of certain Lactococcus bacteria due to the increased lytic activity of certain bacteriophages, such as c2-like and 936-like groups.”

What the team has shown, using a very early patient population, is that patients with PD have a decrease in Lactococcus bacteria. The decrease might be implicated as an important initiating factor for the alterations of the aforementioned Lactococcus bacteria.

On the Horizon

Tetz believes the research has high translational potential, and they’re going to start implementing bacteriophages as novel therapeutic targets for treatment and prevention of PD.

“Currently, we’re developing the pipeline for triggering phages, as well as novel ways for the microbiome transplantation,” said Tetz. “We also believe that certain alterations can be used to develop diagnostic systems for very early detection of Parkinson’s Disease.”

Aside from PD, the research may impact other neurodegenerative pathologies.

“We believe that identifying bacteriophages as new targets and new causative agents is a very important step for medicine because these targets will lead to principally new therapies and diagnostics,” Tetz said.

The article was updated on June 26 at 9:52 a.m. with new information.

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