Alzheimer’s disease (AD) is a neurodegenerative disease that usually affects older individuals. Owing to the higher incidence of root caries and missing teeth in elderly individuals, the bacteria involved in these dental concerns might potentially deteriorate their cognitive function. Altered microbiota in the oral cavity may induce neuroinflammation through migration from the oral cavity to the brain. However, the correlation between the composition of the oral microbiota and neurodegenerative disease remains unclear. In this study, we evaluated sequence to determine the relative abundance and diversity of bacterial taxa in the dental plaque of elderly patients with AD and controls. Oral samples; the DMFT index; and other clinical examination data were collected from 17 patients with AD and 18 normal elderly individuals as the control group. Patients with AD had significantly more missing teeth and higher dental plaque weight but lower microbial diversity than controls. Significantly increased numbers of Lactobacillales, Streptococcaceae, and Firmicutes/Bacteroidetes and a significantly decreased number of Fusobacterium were observed in patients with AD. In conclusion, using the PacBio single-molecule real-time (SMRT) sequencing platform to survey the microbiota dysbiosis biomarkers in the oral cavity of elderly individuals could serve as a tool to identify patients with AD.

Original languageEnglish
Article number4211
JournalInternational journal of environmental research and public health
Issue number8
Publication statusPublished - Apr 2021


  • Alzheimer’s disease
  • Dental hygiene
  • Neuroscience/neurobiology
  • Oral health
  • Oral microbiota
  • Plaque/plaque biofilms

ASJC Scopus subject areas

  • Public Health, Environmental and Occupational Health
  • Health, Toxicology and Mutagenesis


Dive into the research topics of 'Oral microbiota changes in elderly patients, an indicator of alzheimer’s disease'. Together they form a unique fingerprint.

Cite this