Time Of Death Can Be Estimated Through The Body Microbiome, Study Reveals
Estimation of the exact time of death of cadavers is highly crucial for forensic applications. The presently used techniques that help people estimate the time lapse after the death of the body are imprecise. Researchers at the City University of New York (CUNY) have developed a more accurate method of calculating the time of death of cadavers.
The researchers used the next-generation sequencing methods to study the microbiome of the 21 dead bodies at various intervals of time. The sample were collected from the ear and nasal cavities of the cadavers after specified time intervals, over several weeks of decomposition.
The study was conducted at John Jay College of Criminal Justice, New York, under the leadership of Nathan H. Lents. The results obtained by the researchers were carefully analyzed for the type of microbes present on and inside the dead bodies and the change of their relative abundance over the period of decomposition, according to Business Standard.
A machine learning approach was then used to scrutinize and analyze the data collected, which was then used for the development of a statistical model. The model can be used to predict the post-mortem interval of cadavers within 55 accumulated degree-days at a time or two days during summertime.
Researchers claim that the model is highly efficient in predicting the elapsed time after death with high accuracy, even after several weeks of body decomposition. Lents, the lead researcher of the study, said, "Our approach had the benefit of sampling the same cadavers repeatedly as they decomposed" and stated that "this really added to the ability of our machine learning approach to see through all of the massive amount of noisy data and detect the underlying patterns."
The study has already been published in the PLOS ONE journal, and it is applauded by forensic experts all over the world. Dr. Robert DeSalle, Curator of Molecular Systematics, American Museum of Natural History, said that "This study takes us a step further (than the human microbiome), and tells us about the necrobiome, the collection of microbes on a dead body."
The newly developed technique may be used as a standardized method of calculation of time of death of cadavers and dead biological samples for both forensic and research purposes.