Scientists analyzing 1,300-year-old human feces from the Dead Children’s Cave in Mexico found that more than 1,000 years ago people often suffered from nasty intestinal infections.
“Working with these ancient samples is like opening a biological time capsule, with each sample revealing insights about human health and daily life,” study lead author Drew Capone, assistant professor of environmental health at Indiana University, said in a statement.
Capone and his colleagues used molecular analysis techniques to study 10 ancient dried fecal samples (also called paleostools) dating from 725 to 920 AD, discovered in a cave in Mexico’s Rio Zape Valley, just north of the city of Durango in northwestern Mexico. The researchers published their findings in the academic journal PLOS One on Wednesday (October 22).
you may like
In the late 1950s, archaeologists excavated the Cave of Dead Children and recovered ancient human and non-human feces, plant remains, and animal and human bones from a large trash pile. This cave was used by the prehistoric Roma San Gabriel culture people. They practiced small-scale farming, produced unique pottery, lived in small villages, and sometimes performed child sacrifice. Archaeologists named this cave after the skeleton of a child discovered there.
Previous studies of paleo-faeces from caves have revealed the presence of hookworm, whipworm and pinworm eggs, suggesting that people who dumped faeces in caves were infected with a variety of parasites.
In a new study, scientists used cutting-edge molecular techniques to detect additional microorganisms in paleofecal matter from 10 “different defecation events”, with the aim of improving understanding of the burden of disease in Roma people. “There are many possibilities for applying modern molecular methods that inform past research,” study co-author Joe Brown, a professor of environmental science at the University of North Carolina at Chapel Hill, said in a statement.
The researchers extracted DNA from 10 old fecal samples and used polymerase chain reaction (PCR) to amplify the microbial DNA in the feces. All samples contained at least one pathogen or gut microbe, and the two most common were the intestinal parasite Blastocystis, which can cause gastrointestinal problems, and E. coli, a strain of bacteria found in multiple strains in 70% of the samples. In addition, pinworms, fungi that can cause intestinal diseases, and fungi such as rubella and giardia were also found.
The large number of microorganisms found in the paleofeces “suggests that the Loma-San Gabriel culture had poor hygiene conditions between 600 and 800 AD, resulting in exposure to fecal waste in the environment,” the researchers wrote in their study. The researchers added that people likely ingested the microorganisms through drinking water, soil or food contaminated with feces.
Although these pathogen-related genes persisted in old feces for up to 1,300 years, there may have been many more pathogens in the samples, which then decayed and became undetectable, the researchers noted in the study.
Still, new analyzes have uncovered DNA from pathogens not previously found in paleofeces, including Blastocystis and Shigella.
“Applying these methods to other ancient samples may improve our understanding of how ancient people lived and the pathogens that may have affected their health,” the researchers wrote.
Source link
