The Microbial Forensic Clock

Today's story is for the CSI fan. Researchers are learning about the various microbes present in and on our bodies after death. This means there's a sort of microbial clock that reveals when and how a person died.

There are research facilities around the country that are virtual human body farms where people study decaying human bodies in different geographical environments and seasons. Typically the donated cadavers are placed outdoors and allowed to decompose. Researchers take samples from a defined body area over weeks. A DNA analysis is done to reveal the microbial species present and Scientists learned that different sets of microbial communities appeared during each phase of decay.

For example, certain microbes are found on fresh bodies which are then replaced with new groups of microbes in waves as decay advances. The succession of microbial species over time was consistent from body to body and the different seasons, but they did vary some by geographical location.

Because our microbiome alters as our health changes and especially if we're taking medication, studying their impact on the microbes in and on our bodies can also help scientists improve their ability to provide information about a dead body.

This work is valuable to forensic investigations. Even though most medical examiner's offices won't have the molecular tools for this type of analysis and any information would need to pass the muster of the criminal courts, experts predict that within five years, the concept of a forensic microbial clock will become accepted.