The human salivary microbiome exhibits temporal stability in bacterial diversity.

The temporal variability of the human microbiome may be an important factor in determining its relationship with health and disease. In this study, the saliva of 40 participants was collected every 2 months over a one-year period to determine the temporal variability of the human salivary microbiome. Salivary pH and 16S rRNA gene copy number were measured for all participants, with the microbiome of 10 participants assessed through 16S rRNA amplicon sequencing. In February 2013, 16S rRNA gene copy number was significantly (P < 0.001) higher, with individual changes between time points significant (P = 0.003). Salivary pH levels were significantly (P < 0.001) higher in December 2012 than in October 2012 and February 2013, with significant (P < 0.001) individual variations seen throughout. Bacterial α-diversity showed significant differences between participants (P < 0.001), but not sampling periods (P = 0.801), and a significant positive correlation with salivary pH (R(2) = 7.8%; P = 0.019). At the phylum level, significant differences were evident between participants in the Actinobacteria (P < 0.001), Bacteroidetes (P < 0.001), Firmicutes (P = 0.008), Fusobacteria (P < 0.001), Proteobacteria (P < 0.001), Synergistetes (P < 0.001) and Spirochaetes (P = 0.003) phyla. This study charted the temporal variability of the salivary microbiome, suggesting that bacterial diversity is stable, but that 16S rRNA gene copy number may be subject to seasonal flux.

[1]  Mihai Pop,et al.  Deep Sequencing of the Oral Microbiome Reveals Signatures of Periodontal Disease , 2012, PloS one.

[2]  P. Hugenholtz,et al.  Respiratory Syncytial Virus Infection is Associated with Increased Bacterial Load in the Upper Respiratory Tract in Young Children , 2013 .

[3]  George M. Weinstock,et al.  Genomic approaches to studying the human microbiota , 2012, Nature.

[4]  M. Falagas,et al.  Exposure to cold and respiratory tract infections. , 2007, The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease.

[5]  R. Knight,et al.  Bacterial Community Variation in Human Body Habitats Across Space and Time , 2009, Science.

[6]  S. Takashiba,et al.  Quantitative real-time PCR using TaqMan and SYBR Green for Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, tetQ gene and total bacteria. , 2003, FEMS immunology and medical microbiology.

[7]  Andreas Wilke,et al.  phylogenetic and functional analysis of metagenomes , 2022 .

[8]  Kang Ning,et al.  Saliva microbiomes distinguish caries-active from healthy human populations , 2011, The ISME Journal.

[9]  M. Timmerman,et al.  Plaque development in relation to the periodontal condition and bacterial load of the saliva. , 2004, Journal of clinical periodontology.

[10]  J. Linder,et al.  Human rhinovirus C: Age, season, and lower respiratory illness over the past 3 decades , 2012, Journal of Allergy and Clinical Immunology.

[11]  Steven Salzberg,et al.  BIOINFORMATICS ORIGINAL PAPER , 2004 .

[12]  Kun Tang,et al.  Global diversity in the human salivary microbiome. , 2009, Genome research.

[13]  M. Timmerman,et al.  The effect of periodontal treatment on the salivary bacterial load and early plaque formation. , 2004, Journal of clinical periodontology.

[14]  Katherine H. Huang,et al.  Structure, Function and Diversity of the Healthy Human Microbiome , 2012, Nature.

[15]  James R. Cole,et al.  The Ribosomal Database Project: improved alignments and new tools for rRNA analysis , 2008, Nucleic Acids Res..

[16]  A. Klindworth,et al.  Evaluation of general 16S ribosomal RNA gene PCR primers for classical and next-generation sequencing-based diversity studies , 2012, Nucleic acids research.

[17]  R. Genco,et al.  A proposed model linking inflammation to obesity, diabetes, and periodontal infections. , 2005, Journal of periodontology.

[18]  G. V. D. Van der Weijden,et al.  Tongue coating and salivary bacterial counts in healthy/gingivitis subjects and periodontitis patients. , 2001, Journal of clinical periodontology.

[19]  T. Kudo,et al.  Molecular analysis of bacterial microbiota in the gut of the termite Reticulitermes speratus (Isoptera; Rhinotermitidae). , 2003, FEMS microbiology ecology.

[20]  R. Genco,et al.  A Proposed Model Linking Inflammation to Obesity, Diabetes, and Periodontal Infections. , 2005, Journal of periodontology.

[21]  Walter C. Willett,et al.  Periodontal Disease, Tooth Loss, and Incidence of Ischemic Stroke , 2003, Stroke.

[22]  Francesco Salvatore,et al.  The Personal Human Oral Microbiome Obscures the Effects of Treatment on Periodontal Disease , 2014, PloS one.

[23]  David S. Wishart,et al.  MetaboAnalyst 2.0—a comprehensive server for metabolomic data analysis , 2012, Nucleic Acids Res..

[24]  F. Scannapieco.  The oral microbiome: Its role in health and in oral and systemic infections , 2013 .

[25]  G. Davison,et al.  Effects of bovine colostrum supplementation on upper respiratory illness in active males , 2014, Brain, Behavior, and Immunity.

[26]  G. Seymour,et al.  Relationship between periodontal infections and systemic disease. , 2007, Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases.

[27]  P. Barrett,et al.  Molecular pathways involved in seasonal body weight and reproductive responses governed by melatonin , 2012, Journal of pineal research.

[28]  C. Deming,et al.  Topographical and Temporal Diversity of the Human Skin Microbiome , 2009, Science.

[29]  R. Knight,et al.  Moving pictures of the human microbiome , 2011, Genome Biology.

[30]  S. Humphrey,et al.  A review of saliva: normal composition, flow, and function. , 2001, The Journal of prosthetic dentistry.

[31]  Falagas Me,et al.  Exposure to cold and respiratory tract infections. , 2007 .

[32]  Rob Knight,et al.  Nurture trumps nature in a longitudinal survey of salivary bacterial communities in twins from early adolescence to early adulthood , 2012, Genome research.

[33]  Levi Waldron,et al.  Composition of the adult digestive tract bacterial microbiome based on seven mouth surfaces, tonsils, throat and stool samples , 2012, Genome Biology.

[34]  Michal Kielbik,et al.  Seasonal changes in activities of human neutrophils in vitro , 2011, Inflammation Research.

[35]  J. Izard,et al.  The Human Oral Microbiome , 2010, Journal of bacteriology.

[36]  J. A. Aas,et al.  Defining the Normal Bacterial Flora of the Oral Cavity , 2005, Journal of Clinical Microbiology.

[37]  M. Blaser,et al.  The human microbiome: at the interface of health and disease , 2012, Nature Reviews Genetics.