Mortician Holly Williams, 28, has worked on around 1,000 bodies at a family-run funeral home in north Texas. She describes how the freshness of a body affects her work, with recently deceased individuals being easier to handle than those found days after death. John, a 57-year-old former oil field worker, died of a heart attack and was brought to her four hours later, already showing early signs of decomposition.
Decomposition begins minutes after death with autolysis, or self-digestion. Cells deprived of oxygen increase in acidity, and enzymes start breaking down cell membranes. This process typically starts in the liver and brain, then spreads to other tissues. Blood cells leak from vessels, settling due to gravity and discolouring the skin. Body temperature drops to match the surroundings, and rigor mortis sets in, starting in the eyelids and jaw before moving to the trunk and limbs.
After death, the body becomes an ecosystem teeming with bacteria. The gut microbiome, containing trillions of bacteria from hundreds of species, is a key area of study. In August 2014, forensic scientist Gulnaz Javan of Alabama State University published the first study of the thanatomicrobiome, examining microbial changes after death using samples from criminal cases.
Javan notes that many samples come from suicides, homicides, drug overdoses, or traffic accidents. This emerging field aims to understand how the microbial community evolves during decomposition, potentially aiding forensic investigations.
