The type of bacteria involved in human decomposition can change over time. Understanding this could help scientists understand the time of death of a corpse.
Determining the time of death of a person is difficult and one of the oldest and established ways is to see if there are any maggots. Here knowing the size of the maggot and its distance from the corpse can help determine the time of death.
Scientists are trying to develop a more reliable way by examining the different types and communities of bacteria, and to show how these change. This has been facilitated through advanced genetic techniques.
The latest research has been led by Aaron Lynne and colleagues at Sam Houston State University and Baylor College of Medicine. For this, the team examined the decomposition of two human bodies under natural conditions. They assessed bacterial biodiversity using a gene sequencing method of analyzing bacterial DNA.
The researchers found that these bacterial communities were different between the two bodies and between regions on the same body, and these communities changed over the time-course of decomposition. From this, the authors suggest that bacterial communities may be following specific, changing patterns as a corpse moves through its natural stages of decomposition. Understanding this more fully should reveal information about the time of death and aid those working in forensics.
A review of the research to date has been published in the journal PLOS ONE. The paper is titled “The Living Dead: Bacterial Community Structure of a Cadaver at the Onset and End of the Bloat Stage of Decomposition.”