Source: http://www.newscientist.com/article/mg22...

MILLIONS want you dead. No, it's not a Twitter conspiracy, but a battle raging beneath your skin. The cells in your body are outnumbered 10 to one by microbial cells, and like it or not, eventually the microbes will win.

Surprisingly, what happens next has largely been a mystery. Now researchers have made the first study of the thanatomicrobiome – the army of gut microbes that take over your internal organs once you are dead. The results could have applications in forensic science and medicine.

While we are alive, the 100 trillion bacteria resident in our gut work on our behalf. They ease digestion and keep the immune system functioning smoothly, in exchange for a constant supply of food. These "friendly" bacteria adhere to the lining of the gut and keep the microbial villains at bay by outcompeting them.

After we die, however, our gut flora have a party. Dying cells leak carbohydrates, amino acids and lipids, causing a frenzy of microbial feeding and reproduction. The bacteria eventually escape the gut and swarm through the circulatory and lymph systems, spreading to organs that are shielded during life by the immune system.

Understanding how microbes inside a dead body colonise it can help pathologists work out the time of death, where the body has been lying, and how its decomposition could affect the soil and ecology around it.