Microbes Can Tell Scientists Exactly How Long a Body’s Been Decaying

Just like insects, different types of microbes colonize a decaying body at different times during the process of decomposition. And new research indicates that working out the timing behind this procession could provide a “microbial clock” used to determine approximate time of death—often a crucial piece of information for investigators, the Colorado University, Boulder, authors say in a statement.

To test this concept, the team used gene sequencing to identify bacteria, fungi, nematodes and amoebas on forty mice corpses during different states of decay over a 48 day period. “Microbial community changes are dramatic, measurable, and repeatable,” they report in their paper, and they were able to use those data to estimate how long the mice had been dead within about a three day resolution.  

The CU researchers aren’t the only ones working on this problem. At the Southeast Texas Applied Forensic Science Facility, home to one of the country’s outdoor “body farms,” researchers are not only trying to pinpoint time of death but also looking at other questions, too, NPR writes. Do the bacterial communities of a person who was beaten to death differ from one who died of old age or disease?  Or, since microbial communities differ depending on place, do they indicate whether a body was killed in one place but dumped in another? Microbes might have all sorts of clues to cough up, if we look closely.

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Rachel Nuwer | | READ MORE

Rachel Nuwer is a freelance science writer based in Brooklyn.