High throughput DNA sequencing to detect differences in the subgingival plaque microbiome in elderly subjects with and without dementia

Cockburn, Dehlin, Ngan Tiffany, Crout Richard, Boskovic Goran, Denvir James, Primerano Donald, Plassman, Wu Bei, Cuff

Description

To investigate the potential association between oral health and cognitive function, a pilot study was conducted to evaluate high throughput DNA sequencing of the V3 region of the 16S ribosomal RNA gene for determining the relative abundance of bacterial taxa in subgingival plaque from older adults with or without dementia. Methods Subgingival plaque samples were obtained from ten individuals at least 70 years old who participated in a study to assess oral health and cognitive function. DNA was isolated from the samples and a gene segment from the V3 portion of the 16S bacterial ribosomal RNA gene was amplified and sequenced using an Illumina HiSeq1000 DNA sequencer. Bacterial populations found in the subgingival plaque were identified and assessed with respect to the cognitive status and oral health of the participants who provided the samples. Results More than two million high quality DNA sequences were obtained from each sample. Individuals differed greatly in the mix of phylotypes, but different sites from different subgingival depths in the same subject were usually similar. No consistent differences were observed in this small sample between subjects separated by levels of oral health, sex, or age; however a consistently higher level of Fusobacteriaceae and a generally lower level of Prevotellaceae was seen in subjects without dementia, although the difference did not reach statistical significance, possibly because of the small sample size. Conclusions The results from this pilot study provide suggestive evidence that alterations in the subgingival microbiome are associated with changes in cognitive function, and provide support for an expanded analysis of the role of the oral microbiome in dementia.

Sujets

• Cognitive dysfunction

Informations

• Publié par: biomed
• Publié le: 01 janvier 2012
• Nombre de lectures: 120
• Langue: English
• Poids de l'ouvrage: 1 Mo

Extrait

Cockburnet al. Investigative Genetics2012,3:19 http://www.investigativegenetics.com/content/3/1/19

R E S E A R C HOpen Access High throughput DNA sequencing to detect differences in the subgingival plaque microbiome in elderly subjects with and without dementia 1 12 23 3 Andrew F Cockburn , Jonathan M Dehlin , Tiffany Ngan , Richard Crout , Goran Boskovic , James Denvir , 3 45 1* Donald Primerano , Brenda L Plassman , Bei Wuand Christopher F Cuff

Abstract Background:To investigate the potential association between oral health and cognitive function, a pilot study was conducted to evaluate high throughput DNA sequencing of the V3 region of the 16S ribosomal RNA gene for determining the relative abundance of bacterial taxa in subgingival plaque from older adults with or without dementia. Methods:Subgingival plaque samples were obtained from ten individuals at least 70 years old who participated in a study to assess oral health and cognitive function. DNA was isolated from the samples and a gene segment from the V3 portion of the 16S bacterial ribosomal RNA gene was amplified and sequenced using an Illumina HiSeq1000 DNA sequencer. Bacterial populations found in the subgingival plaque were identified and assessed with respect to the cognitive status and oral health of the participants who provided the samples. Results:More than two million high quality DNA sequences were obtained from each sample. Individuals differed greatly in the mix of phylotypes, but different sites from different subgingival depths in the same subject were usually similar. No consistent differences were observed in this small sample between subjects separated by levels of oral health, sex, or age; however a consistently higher level of Fusobacteriaceae and a generally lower level of Prevotellaceae was seen in subjects without dementia, although the difference did not reach statistical significance, possibly because of the small sample size. Conclusions:The results from this pilot study provide suggestive evidence that alterations in the subgingival microbiome are associated with changes in cognitive function, and provide support for an expanded analysis of the role of the oral microbiome in dementia. Keywords:Cognitive impairment, Oral disease, Oral microbiome, Subgingival plaque

Background In addition to the hypothesized link between oral health and chronic systemic diseases, such as cardiovascular disease, stroke, and diabetes, there now appears to be an association between oral health and neurodegenerative diseases, ranging from mild to moderate loss of cognitive function to Alzheimer’s Disease (AD) [1]. Poorer cogni tive performance and tooth loss have been linked

* Correspondence: [e-mail] 1 Microbiology, Immunology & Cell Biology, School of Medicine, Robert C. Byrd Health Sciences Center, West Virginia University, P.O. Box 4622, Morgantown, WV 265064622, USA Full list of author information is available at the end of the article

epidemiologically in both retrospective and prospective studies [27], and tooth loss has been associated with an increased risk of both dementia and cognitive decline [8]. Indeed, increasing tooth loss over time is associated with increased likelihood of low cognitive scores [2]. Be yond epidemiological associations, independent lines of experimental evidence support the hypothesis that bac teria associated with diseases of the oral cavity contrib ute to neurodegeneration. Oral bacteria and bacteria closely related to those found in the oral cavity have been found at a higher frequencypost mortemin the brains of patients with AD than in those of patients who did not have AD [9,10]. In addition, the Third National

© 2012 Cockburn et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.