Studies show an association between the gut microbiome and Parkinson's disease. Up until now, though, no studies had investigated the role fungi played in the gut. Now, however, researchers from the University of British Columbia have found that gut fungi are not a contributing factor to the condition.
For their study, the researchers recruited 95 patients with Parkinson's disease and 57 controls from the Pacific Parkinson's Research Center at the University of British Columbia. Each participant provided a fecal sample, while those with Parkinson's underwent a two-hour examination to assess their symptoms.
All in all, the researchers found that fungi were overall very sparse among the participants' fecal microbiomes. They were so sparse, in fact, that 46 participants were excluded from downstream compositional analysis as they had almost no detectable fungal genomic content in their stool. Most of the fungi detected were of environmental or dietary origin.
From their analysis, the researchers ultimately found no significant difference between the microbiomes of those with Parkinson's and those without. Nevertheless, they found that those with Parkinson's disease tended to have a lower overall fungal abundance than those without the condition. This, they say, may be due to their less hospitable gut environment.
"The data are an important piece in the puzzle of understanding the overall role of the gut microbiome in PD," says Dr. Silke Appel-Cresswell, lead investigator of the study. "PD patients can rest assured that gut fungal overgrowth, or dysbiosis, is likely not a contributing factor to any of their PD symptoms, both motor and non-motor."
"The gut microbiome in PD continues to be an exciting field of research where we are just at the beginning of unraveling potential mechanisms. It will be important to publish negative results as well as positive findings along with detailed methods to have a realistic reflection of the data in the literature to accelerate discovery."