Mini-Review Article – Current Opinion on Salivary Biomarkers as a Measurement for Stress and Fatigue

Salivary biomarkers have been increasingly popular in stress research as saliva is easily produced and collection is non-invasive and not limited by geographical distance or lack of infrastructure. Several salivary biomarkers have been utilized in stress research, for instance, salivary cortisol, salivary amylase and salivary immunoglobulin A. Despite being sensitive to changes in fatigue, they have limitations such as inter-individual variability, and interactions with other constituents that may confound the results. Recently, Hyperion Biotechnology has developed the Fatigue Biomarker Index (FBI), which is a measurement of the changes in concentration of salivary peptides with fatigue. The FBI has been shown to be an accurate and objective biomarker of fatigue, and has huge potential for use in various fields and industries. This article will review some of the previous and current salivary biomarkers of stress, as well as critically appraise the new salivary peptide test in terms of its accuracy, application and access.