While there are certain microbes that are common to most people, every individual’s microbiome is unique. That means that some day, forensic scientists could use the microbial traces we leave behind to identify criminals. It may seem like the stuff ofCSI, but according to Dr. Jack Gilbert, a microbiome researcher at Argonne National Laboratory, the technique could see use sooner than you think.
Gilbert and his colleagues are working with the Department of Justice to identify whether “microbiome fingerprints” have the potential to be used as trace evidence in court cases. To test the potential, the research team worked with police officer in Fort Lauderdale, Florida, to stage a phony robbery.
The “robbers”—graduate students of a professor involved in the study—entered a home and put on their best faux robbery, removing items like iPads, laptops, and a TV, and even stopping to grab a drink from the refrigerator. After the bogus burglary was over, researchers entered in sterile gear and took samples of the microbes in the house. By analyzing these samples, Gilbert and his team were able to pick out a pair of signatures that didn’t belong.
“Even though these were very limited interactions, they left behind identifiable traces,” says Gilbert.
More than that, they were also able to identify surprising things about the signatures, like that one of the participants in the burglary took migraine medication, which Gilbert says “changes the microbiome in a predictable way.”
Just as a pair of gloves can foil fingerprinting, there are ways to avoid leaving a microbial signature at the scene of a crime—they are just more bulky. To prevent microbial fingerprints from lingering, criminals would have to trade their traditional ski masks for full Hazmat suits, a conspicuous solution if there ever was one.