title: Not all biofluids are created equal: chewing over salivary diagnostics and the epigenome.
abstract: OBJECTIVE
  This article describes progress to date in the characterization of the salivary epigenome and considers the importance of previous work in the salivary microbiome, proteome, endocrine analytes, genome, and transcriptome.
  
  
  METHODS
  PubMed and Web of Science were used to extensively search the existing literature (original research and reviews) related to salivary diagnostics and biomarker development, of which 125 studies were examined. This article was derived from the most relevant 74 sources highlighting the recent state of the evolving field of salivary epigenomics and contributing significantly to the foundational work in saliva-based research.
  
  
  RESULTS
  Validation of any new saliva-based diagnostic or analyte will require comparison to previously accepted standards established in blood. Careful attention to the collection, processing, and analysis of salivary analytes is critical for the development and implementation of newer applications that include genomic, transcriptomic, and epigenomic markers. All these factors must be integrated into initial study design.
  
  
  CONCLUSIONS
  This commentary highlights the appeal of the salivary epigenome for translational applications and its utility in future studies of development and the interface among environment, disease, and health.
authors.affiliation: Neuroscience Graduate Program, Tulane University, New Orleans, Louisiana; Department of Psychiatry and Behavioral Science, Tulane University School of Medicine, New Orleans, Louisiana.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Wren
authors.affiliation: Department of Human Development and Family Studies, Iowa State University, Ames, Iowa.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Shirtcliff
authors.affiliation: Neuroscience Graduate Program, Tulane University, New Orleans, Louisiana; Department of Psychiatry and Behavioral Science, Tulane University School of Medicine, New Orleans, Louisiana. Electronic address: sdrury@tulane.edu.
authors.forename: Stacy S
authors.initials: SS
authors.lastname: Drury
mesh_terms: D015415:Biomarkers / Q000032:analysis; D019175:DNA Methylation; D003933:Diagnosis; D057890:Epigenomics / Q000379:methods*; D020869:Gene Expression Profiling; D016678:Genome; D006801:Humans; D008409:Mastication; D035683:MicroRNAs / Q000032:analysis; D064307:Microbiota; D020543:Proteome / Q000032:analysis*; D012463:Saliva / Q000737:chemistry* / Q000382:microbiology*; D016615:Telomere
chemical_list: D015415:Biomarkers; D035683:MicroRNAs; D020543:Proteome
keywords: DNA methylation; biomarker; epigenome; salivary diagnostics; salivary transcriptome; telomere length