title: Oral and nasal microbiota in Parkinson's disease.
abstract: Parkinson's disease (PD) is associated with neuropathological changes in olfactory and gastrointestinal tissues, and PD patients frequently suffer from hyposmia, hyposalivation, and dysphagia. Since hyposmia and gastrointestinal dysfunction are frequently premotor symptoms, it has been speculated that an external, for example microbial, agent could trigger the pathologic process in the corresponding organs, subsequently spreading to the central nervous system. We recently showed evidence for compositional differences between the fecal microbiota of PD patients and control subjects. In this study, our objective was to explore a possible connection between nasal and oral microbiota and PD.
  
  
  
  We compared the oral and nasal bacterial communities of PD patients (oral: n = 72, nasal: n = 69) and control subjects (oral: n = 76, nasal: n = 67) using a 16S rRNA gene amplicon sequencing approach.
  
  
  
  Oral and nasal microbiota differed markedly from each other, with no notable similarity within subjects. Oral microbiota of PD patients and control subjects had differences in beta diversity and abundances of individual bacterial taxa. An increase in the abundance of opportunistic oral pathogens was detected in males, both with and without PD. Our data did not reveal convincing differences between the nasal microbiota of control subjects and PD patients.
  
  
  
  The oral microbiome deserves additional research regarding its connection to PD and its biomarker potential. The higher abundance of oral pathogens in men underlines the importance of monitoring and promoting male dental health.
authors.affiliation: Institute of Biotechnology, DNA Sequencing and Genomics Laboratory, University of Helsinki, Viikinkaari 5D, 00014, Finland.
authors.forename: Pedro A B
authors.initials: PAB
authors.lastname: Pereira
authors.affiliation: Institute of Biotechnology, DNA Sequencing and Genomics Laboratory, University of Helsinki, Viikinkaari 5D, 00014, Finland.
authors.forename: Velma T E
authors.initials: VTE
authors.lastname: Aho
authors.affiliation: Institute of Biotechnology, DNA Sequencing and Genomics Laboratory, University of Helsinki, Viikinkaari 5D, 00014, Finland.
authors.forename: Lars
authors.initials: L
authors.lastname: Paulin
authors.affiliation: Department of Neurology, Helsinki University Hospital, and Clinical Neurosciences, Neurology, University of Helsinki, Haartmaninkatu 4, 00290 Helsinki, Finland.
authors.forename: Eero
authors.initials: E
authors.lastname: Pekkonen
authors.affiliation: Institute of Biotechnology, DNA Sequencing and Genomics Laboratory, University of Helsinki, Viikinkaari 5D, 00014, Finland.
authors.forename: Petri
authors.initials: P
authors.lastname: Auvinen
authors.affiliation: Department of Neurology, Helsinki University Hospital, and Clinical Neurosciences, Neurology, University of Helsinki, Haartmaninkatu 4, 00290 Helsinki, Finland. Electronic address: filip.scheperjans@hus.fi.
authors.forename: Filip
authors.initials: F
authors.lastname: Scheperjans
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D064307:Microbiota / Q000235:genetics; D008875:Middle Aged; D009296:Nasal Cavity / Q000382:microbiology*; D009666:Nose / Q000382:microbiology*; D010300:Parkinson Disease / Q000382:microbiology* / Q000473:pathology*; D012737:Sex Factors; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires
keywords: Autonomic dysfunction; Biomarker; Dysautonomia; Microbiome; Non-motor symptoms