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MSU and Detroit analyze tiny bacteria to investigate murders

Oct 29, 2014

It sounds like "CSI" meets "Bones." 

Eric Benbow looks at the tiny bacteria on our bodies to see how long a body has been dead, and maybe even where it's been.
Credit Michigan State University / http://msutoday.msu.edu/news/2014/msu-partners-with-detroit-to-investigate-death-scenes/

The Wayne County Medical Examiner is sending swab samples from dead bodies to Michigan State University researchers.

They're going to run a new kind of analysis in hopes of determining when someone died, whether they touched a weapon, and possibly even where they've been. 

What they’re looking at are the teeny-tiny things that live on our bodies: microbes.

These tiny organisms on our bodies are constantly evolving, even after we die, like a "microbial clock, to identify how long someone's been dead."

You can’t see them with the naked eye, but we all have bacteria, fungi, and even tiny worms that live on our bodies and form their own ecosystems.

Those “microbiome communities,” as they’re called, turn out to be kind of like fingerprints.

And since they’re constantly evolving, even after we die, scientists think they could read them like a “microbial clock, to identify how long someone’s been dead,” says Eric Benbow, MSU entomologist and osteopathic medical specialist.

He says this partnership with the medical examiner’s office is groundbreaking research that could advance what we think of as forensics.

But so far, they just don’t know exactly how much they can tell from these tiny organisms.

“Can we use these communities to identify whether a person is from a certain location or if they’ve been to a location?” asks Benbow.

All these tiny gross things live on you, changing constantly. And when you die, they're still there.
Credit NIH / nih.gov

“Have they eaten certain types of foods? Are there certain microbes that may be a signature from being in a certain location?

"That’s what we’re hoping to find out. We don’t know yet.”

The Department of Justice is giving MSU about $433,000 in grant money to keep working on this with Wayne County.  

So how long until this research can be applied to a real crime scene?

Benbow says they’re at the very beginning of analyzing what they’ve gathered from Wayne County so far.

You can use "microbial communities [to show how] a human hand [may have come in contact with] a weapon."

But he’s pretty sure that they’ll be able to help figure out a more precise time of death in the near future by tracking the evolution of microbes.

“Because the microbes change so quickly on bodies, we may be able to increase the [precise time of death] from, say, two to four days or even a week, to 12 hours or 24 hours.”  

What’s more, he says, there’s at least one other possibility: the ability to identify where someone has been before they died.

“Did those activities lead to their death?” asks Benbow.

He points to previous studies that suggest people living in the same house have far more similar microbiome communities than people who don’t live together.

"And so it’s a new tool that I think will help support other evidence that they would normally collect and refine some of the timelines and information that’s important to the investigation," Benbow says.

“I just read a paper recently where they’re using the microbial communities [to show how] a human hand [may have come in contact with] a weapon. So we’re not the first people to investigate this, but it’s beginning to show usefulness,” Benbow says.

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