I was watching a documentary on TV once where they were Excavating an archaeological site that was several thousand years old. He found a location of a toilet pit and found bits of ancient poo. In trying to identify the types of food that the people had been eating they actually took samples of the Poo and rehydrated them so that they could test and analyze the samples. When they rehydrated the Poo samples the lab technician was pointing out to the interviewer that the Poo was beginning to smell just like poo once it was rehydrated.