DNA analysis of sediment from ancient toilets has revealed just how unhygienic past diets were in Europe and the Near East. DNA of parasites such as roundworm and whipworm were present in most archaeological latrines studied. The parasite DNA also shows that people were eating under-cooked fish and pork further contributing to ill-health.
High-resolution insight into parasitic infections and diet of past populations in Northern Europe and the Middle East (500 BC- 1700 AD) was obtained by pre-concentration of parasite eggs from ancient latrines and deposits followed by shotgun sequencing of DNA. Complementary profiling of parasite, vertebrate and plant DNA proved highly informative in the study of ancient health, human-animal interactions as well as animal and plant dietary components. Most prominent were finding of soil-borne parasites transmitted directly between humans, but also meat-borne parasites that require consumption of raw or undercooked fish and pork.