For researchers who study Parkinson’s disease, a new frontier of investigation is emerging: the micro-organisms, including viruses, bacteria and fungi that live in and on us.

With funding from Parkinson Canada and Parkinson Society British Columbia, Dr. Silke Appel-Cresswell at the University of British Columbia, is studying changes to our sense of smell and in our gut, which occur long before the tremor, stiffness and trouble walking that are the classic motor symptoms of Parkinson’s.

Appel-Cresswell and her colleagues know that the internal surface of the nose and the entire gut are heavily populated by microbes.

“It turns out that the microbes outnumber the number of cells that are human by a factor of 100,” she says. “We have more microbes in our system than human cells.”

Appel-Cresswell wonders if the fungi in the gut influence the development of Parkinson’s disease. If she can establish a relationship between fungi and the symptoms of the disease, follow-up studies could examine the mechanisms by which fungi might influence the development of Parkinson’s disease.

This line of research might eventually lead to treating the fungi with antifungal medications, for example, to see if eliminating or reducing the fungus in the body also eliminates Parkinson’s. Alternatively, it might also be possible to boost other microbes in the body, using non-invasive measures like probiotics.

“The really exciting thing would be if, in the future, we could look at people at high risk of Parkinson’s and treat them early,” Appel-Cresswell says. Identifying what role the human microbiome plays in disease is truly a new frontier for medicine, she adds.

“It is something that is easily accessible and modifiable, so it holds promise for treatment.”