A scientific breakthrough from Tel Aviv University (TAU) and Haifa University may facilitate speedy, objective, and accurate diagnosis of people suffering from PTSD using saliva samples. As part of the study, the researchers characterized the psychological, social, and medical conditions of about 200 participants while collecting saliva samples from them.

The findings show a typical microbial picture in the saliva of veteran soldiers who had experienced combat stress-related reactions and are currently suffering from post-trauma. According to the researchers, these results may help in the future to reach an accurate and objective diagnosis of people suffering from post-trauma, and to develop microbiotic-related medications associated with the body’s microbial ecology.

The study was led by Professor Illana Gozes and included Professor Noam Shomron, Dr. Shlomo Sragovich, and PhD student Guy Shapira of TAU’s Sackler Faculty of Medicine and Sagol School of Neuroscience; Professor Zahava Solomon from TAU’s Gershon Gordon Faculty of Social Sciences; and Professor Abraham Sagi-Schwartz and PhD student Ella Levert-Levitt from the Center for the Study of Child Development and the School of Psychological Sciences at Haifa University. This study was published on July 22, 2022, in Molecular Psychiatry.

The researchers tested a unique group of about 200 Israeli veteran soldiers who had fought in the first Lebanon War in 1982. The test covered various psychological aspects, including sleep, appetite disorders, guilt, suicidal thoughts, social and spousal support, hostility, satisfaction with life, as well as issues of demographics, psychopathology, welfare, health, and education.

Comparing the results of the subjects’ microbial distribution to the psychological results and their responses to the welfare questionnaires, the researchers found that people with PTSD and high psychopathological indications exhibit the same unique signature picture of bacteria in the saliva. According to the researchers, clinicians might now be able to diagnose post-trauma by objective criteria and not just behavioral ones. The saliva bacteria of those exposed to air pollution showed a correlation to the picture with PTSD, while the number of years of education showed a protective influence and a reverse picture of the microbial ecology in the saliva.

“To the best of our knowledge, this is the first depiction of a microbial signature in the saliva among veteran soldiers with PTSD,” Professor Gozes says. “We were surprised to discover that about a third of the PTSD subjects had never been diagnosed with post-trauma, so they never received any recognition from the Ministry of Defense and the official authorities.

“Until now, post-trauma diagnosis has been based solely on psychological and psychiatric measures. Thanks to this study, it may be possible, in the future, to use objective molecular and biological characteristics to distinguish PSTD sufferers, taking into account environmental influences. We hope that this new discovery and the microbial signatures described in this study might promote easier diagnosis of  post-traumatic veteran soldiers so they can receive appropriate treatment.”

This study was also supported by IDF’s Medical Corps Department of Health and Well-Being and Dr. Ariel Ben Yehuda, former chief of the Department and a Department Manager in the Mental Health Medical Center in Shalvata, Clallit Health Services. The study also involved collaboration with the Charité University Medicine in Berlin and its microbiology experts Dr. Markus M. Heimesaat and Professor Stefan Bereswill, as well as Professors Victor Li and Jacqueline Lam of the University of Hong Kong, who are studying the effects of air pollution.