Soldiers with the 82nd Airborne Division conduct stress shoot testing with scientists from the U.S. Army Research, Development and Engineering Command Soldier Center during the Monitoring and Assessing Soldier Tactical Readiness and Effectiveness study. (Photo credit: David Kamm, RDECOM Soldier Center)(Photo credit: David Kamm, NSRDEC)

A Soldier with the 82nd Airborne Division spits into a test tube that researchers from the U.S. Army Research, Development and Engineering Command Soldier Center tested for cortisol levels during a stress shoot test.

Saliva Samples Provide Gauge for Warfighter Readiness

Saliva Samples Provide Gauge for Warfighter Readiness

Brad Kroner

Saliva samples might have implications for evaluating human performance and warfighter readiness, according to ongoing research at the U.S. Army Research, Development and Engineering Command Edgewood Chemical Biological Center (RDECOM ECBC).

By isolating and analyzing certain biomarkers found in saliva, scientists can determine a warfighter’s physical condition and determine whether to pull him out of combat or to extend the recovery time before re-engaging.

“This data could help draw a correlation between various metabolite biomarkers and warfighter performance; for example relating an increase or decrease in a particular marker to performance in a drill or exercise,” said research biologist Trevor Glaros, Ph.D.

Basically, this data could enable leaders to determine a warfighter’s status almost like a gas gauge in a car or a health bar in a video game. In doing so, troop deployment can be made more effective and strategic, supporting Army priorities like Soldier lethality.

The study, called Monitoring and Assessing Soldier Tactical Readiness and Effectiveness (MASTR-E), started in late May and was conducted in collaboration with the RDECOM Soldier Center and numerous other Army organizations. The program is being observed at a high level, gaining the attention of multiple generals.
Research under the study is diverse and far reaching, but the RDECOM ECBC’s focus is on biomarkers in saliva.

Using liquid chromatography-mass spectrometry (LC-MS), researchers are essentially isolating biomarkers of interest found in saliva and determining which ones might be the best markers of performance. For example, cortisol relates to stress and melatonin relates to the sleep cycle, while lactate relates to muscle fatigue.

Researchers performed a field study with three platoons of paratroopers at Fort Bragg, North Carolina, with saliva samples being taken before, during and after a three-day simulated combat exercise. The field test evaluated Soldiers for strength measurements, sleep, cognition, shooting performance and other exercises.

“We’re looking at biomarkers and how they changed over time to see if there’s a particular way they respond to physical exertion and stress,” explained research biologist Elizabeth Dhummakupt, Ph.D. “With this data, we can say when a specific biomarker reaches a certain level, we should probably pull this Soldier from combat and let him recover.”

“We’re really focused on looking at Soldiers as they recover,” she added. “At what level can we say they’re ready to go back to the field?”

Following that study, researchers are now analyzing over 3,500 saliva samples for eight analytes or biomarkers that correlate to performance. As a part of this study, researchers also obtained “Average Joe” saliva samples from private companies for comparison, Dhummakupt said.

“In general, this is just a human performance study,” she said. “This could mean something for athletes and even the everyday person.”

Devising a process for analyzing the biomarkers required the development of a unique method that now must be refined.

“The literature is sparse in terms of providing a comprehensive technique to look at these analytes,” Glaros said. “Our task in the first phase of this work was to develop a method that could rapidly and quantitatively measure these analytes in the samples.”

Right now, the process takes just eight minutes, “which is pretty fast for liquid chromatography,” Dhummakupt said.

With the first phase — focused on isolating the eight analytes – nearing completion, the team is now looking for an “X-factor” that they weren’t previously looking for.

“At first, we only concentrated on these eight, primary markers,” Dhummakupt said. “But if we open up these filters, then you have an untargeted method where instead of only looking at a select few, I’m looking at everything. How does everything change, globally? The point is to see if there’s an X-factor or a handful of other analytes that are also changing.”

After refining the process and identifying key biomarkers, Glaros and Dhummakupt hope to develop an assay, which could function similarly to a pregnancy test, which could work in the field.

A Soldier with the 82nd Airborne Division spits into a test tube that researchers from the U.S. Army Research, Development and Engineering Command Soldier Center tested for cortisol levels during a stress shoot test.