Researchers Investigate Saliva Proteins as New Biomarkers for Forensic Age and Sex Estimation
Researchers identify salivary proteins that may help forensic investigators estimate age and biological sex, with promising results from 302 participants.
Researchers have identified promising evidence that certain proteins found in human saliva could help forensic investigators estimate a person's age group and biological sex, potentially expanding the investigative value of biological traces recovered from crime scenes.
The findings, reported in the Journal of Forensic and Legal Medicine and indexed on October 30, 2026, examine tannin-binding salivary proteins (TBSPs), particularly proline-rich proteins, as potential biomarkers for forensic identification.
The research involved 302 healthy participants, including 150 males and 152 females, divided into three age groups: 16–22 years, 23–30 years, and over 30 years.
Scientists collected saliva samples and measured protein concentrations using laboratory assays. They then applied statistical methods to determine whether protein levels could distinguish between different demographic groups.
The results showed particularly strong performance in distinguishing participants aged 16–22 from those older than 30. The analysis achieved an area under the receiver operating characteristic curve (AUC) of 0.987, with 93.6% sensitivity and 99.1% specificity.
However, biological sex estimation was considerably less accurate, achieving an overall classification accuracy of 67.5%.
The findings suggest that specific salivary proteins may provide additional investigative information beyond conventional DNA profiling.
Saliva is frequently encountered on objects such as drinking glasses, cigarette butts, clothing and other surfaces, making it a potentially valuable source of forensic evidence.
Nevertheless, the technique remains experimental. The study involved participants from a single institution, and its findings require validation across larger and more diverse populations.
Researchers also need to establish how reliably these proteins can be measured in degraded or environmentally exposed crime-scene samples.
The study highlights the potential of forensic proteomics while emphasizing that salivary protein analysis is not yet a validated replacement for established identification methods.