A radical new approach combining archaeology, genetics and microscopy can reveal long-forgotten secrets of human diet, sanitation and movement from studying parasites in ancient poo, according to new Oxford University research.

Researchers at the University of Oxford's Department of Zoology and School of Archaeology have applied genetic analysis to 700-year-old parasites found in archaeological stool samples to understand a variety of characteristics of a human population. It is the first time this combined parasitological and ancient DNA (aDNA) approach has been applied to understand the epidemiology of historical parasites. The findings have just been published in Proceedings of The Royal Society B.

Gathered from medieval latrines in Lübeck, Germany, these armoured relics that passed through human faeces -- nematode (roundworm) and cestode (tapeworms) eggs -- have tough shells that withstand time and decay, perfectly preserving their DNA.