New research uncovers microbes' role in pinpointing time of death
The journal "Nature Microbiology" published research results on changes occurring in the human body after death. Scientists emphasize the significant role of fungi and bacteria in the decomposition process, suggesting that these microorganisms can provide valuable clues about the time of death. It turns out they know quite a bit about our death.
The study included 36 human corpses from donors who had voluntarily donated their bodies for scientific purposes before death. The bodies were placed in so-called body farms in three different locations: Tennessee, Texas, and Colorado, which varied in climate – temperate, humid, and semi-arid.
What happens to the human body after death?
As reported by Live Science, scientists collected DNA samples from the skin of the deceased and the soil surrounding the bodies during the first 21 days after death. During this time, intensive tissue decomposition occurs—the collected samples served to create a general picture of the microbiome present in each of these locations.
Regardless of location, climate, or season, researchers discovered the same set of about 20 specialized decomposing microorganisms on all 36 bodies. Phys.com notes that these microorganisms appeared at specific moments during the 21-day observation period, and insects were key in their arrival.
The researchers' next step was to use the collected data and previous analyses to create a machine-learning tool. This tool can determine the time elapsed since death with an accuracy of up to three days. Scientists are convinced that their discoveries may be useful in forensic investigations conducted in various climatic conditions. However, they emphasize that further research is necessary to refine the tool.
The goal is for the tool to work in real-world conditions, not just those created for research purposes. Bodies are often buried, wrapped in materials, or placed in water tanks, which limits the access of insects that play a key role in the study. In such situations, the decomposition process may proceed differently, so it is essential to check whether similar patterns emerge.
Prof. David Carter from Chaminade University in Honolulu, a participant in the research, stated: "When we talk about investigating death scenes, there are very few types of physical evidence you can guarantee will be present at every scene. You never know if fingerprints, bloodstains, or camera footage will exist. But microbes will always be there."
