First molecular data on the human roundworm Ascaris lumbricoides species complex from the Bronze and Iron Age in Hallstatt, Austria.

Palaeoparasitological studies can provide valuable information on the emergence, distribution, and elimination of parasites during a particular time in the past. In the prehistoric salt mines of Hallstatt, located in the Austrian Alps, human faeces have been conserved in salt. The aim of this study was to recover ancient DNA of intestinal parasites from these coprolites. Altogether, 35 coprolites from the Hallstatt salt mines, dating back to the Bronze Age mining phase (1158-1063 BCE) and the Iron Age mining phase (750-662 BCE), respectively, were analysed by microscopy and molecular methods. In 91% of the coprolite samples, eggs of soil-transmitted helminths (STH), namely of Trichuris and/or Ascaris were detected by light microscopy. The Ascaris eggs were exceptionally well preserved. For further analysis, DNA was extracted from the palaeofaecal samples and species-specific primers targeting different genes were designed. While amplification of Trichuris DNA remained unsuccessful, sequence data of A. lumbricoides species complex were successfully obtained from 16 coprolites from three different genes, the mitochondrial cytochrome c oxidase subunit 1 gene (cox1), the mitochondrial cytochrome B gene (cytB) and the mitochondrial NADH dehydrogenase subunit 1 gene (nadh1). Importantly, these included two Ascaris sequences from a coprolite from the Bronze Age, which to the best of our knowledge are the first molecular data of this genus from this period.

Hallstatt miners consumed blue cheese and beer during the Iron Age and retained a non-Westernized gut microbiome until the Baroque period.

We subjected human paleofeces dating from the Bronze Age to the Baroque period (18th century AD) to in-depth microscopic, metagenomic, and proteomic analyses. The paleofeces were preserved in the underground salt mines of the UNESCO World Heritage site of Hallstatt in Austria. This allowed us to reconstruct the diet of the former population and gain insights into their ancient gut microbiome composition. Our dietary survey identified bran and glumes of different cereals as some of the most prevalent plant fragments. This highly fibrous, carbohydrate-rich diet was supplemented with proteins from broad beans and occasionally with fruits, nuts, or animal food products. Due to these traditional dietary habits, all ancient miners up to the Baroque period have gut microbiome structures akin to modern non-Westernized individuals whose diets are also mainly composed of unprocessed foods and fresh fruits and vegetables. This may indicate a shift in the gut community composition of modern Westernized populations due to quite recent dietary and lifestyle changes. When we extended our microbial survey to fungi present in the paleofeces, in one of the Iron Age samples, we observed a high abundance of Penicillium roqueforti and Saccharomyces cerevisiae DNA. Genome-wide analysis indicates that both fungi were involved in food fermentation and provides the first molecular evidence for blue cheese and beer consumption in Iron Age Europe.

Bronze Age meat industry: ancient mitochondrial DNA analyses of pig bones from the prehistoric salt mines of Hallstatt (Austria).

OBJECTIVE: In the Bronze Age Hallstatt metropolis ('Salzkammergut' region, Upper Austria), salt richness enabled the preservation of pork meat to sustain people's livelihood suggesting an organized meat production industry on a yearly basis of hundreds of pigs. To pattern the geographic and temporal framework of the early management of pig populations in the surrounding areas of Hallstatt, we want to gain insights into the phylogeographic network based on DNA sequence variation among modern pigs, wild boars and prehistoric (likely) domestic pigs. RESULTS: In this pilot study, we successfully adapted ancient DNA extraction and sequencing approaches for the analysis of mitochondrial DNA sequence variation in ten prehistoric porcine teeth specimens. Minimum-spanning network analyses revealed unique mitochondrial control region DNA haplotypes ranging within the variation of modern domestic pig and wild boar lineages and even shared haplotypes between prehistoric and modern domestic pigs and wild boars were observed.