The oral microbiome of early stage Parkinson's disease and its relationship with functional measures of motor and non-motor functionOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study examined the oral microbiome in early stage Parkinson's disease (PD) using shotgun metatranscriptomic profiling of saliva samples. The researchers profiled both microbial RNA and host mRNA to identify sensitive and specific biomarkers of oral microbiome changes tied to early PD. Prior work in this area had focused mainly on fecal microbiome profiles and patients with more advanced disease, so this study targeted an earlier disease stage and a different body site.
Who was studied?
The study included 48 subjects with PD and 36 age- and gender-matched healthy controls. All participants completed detailed assessments of motor, cognitive, balance, autonomic, and chemosensory (smell and taste) function to characterize disease stage. Saliva samples were then collected from these subjects for microbial RNA and host mRNA sequencing.
What were the most important findings?
Overall alpha and beta diversity did not differ between PD subjects and healthy controls. However, specific microbial taxa did differ between groups, primarily bacteria but also yeast and phage. Nearly half of these findings echoed prior fecal microbiome studies in PD, while others were novel candidates for detecting early stage disease. A diagnostic model using as few as 11 taxonomic features achieved a cross-validated area under the ROC curve of 0.90 and an overall accuracy of 84.5%.
What are the greatest implications of this study?
These findings suggest the oral microbiome, assessed noninvasively through saliva, may offer robust biomarkers for detecting Parkinson's disease at an early stage. The involvement of yeast alongside bacteria and phage points to a broader oral microbial community shift in PD that extends beyond bacterial taxa alone. Because saliva sampling is simpler than fecal sampling, this approach could support more accessible early screening tools pending validation in larger cohorts.