Oetzi the Iceman was found in 1991 in the high Oetzal Alps that span Italy and Austria. He is a mummy who gained popularity in the scientific community because of how well he was preserved and thus the potential to provide a glimpse into Europe’s past (he is thought to be around 5,300 years old, alive in the European Copper Age). Many studies have examined his diet, health, and genetics, but recently researchers were able to discover identify and examine his stomach and intestines. Biopsy samples were collected and PCR analysis determined the presence of the gram-negative bacteria Helicobacter pylori.
H. pylori can be found in about half of the world’s population, and while research has pointed to the harmful effects of this bacterial strain, recent work has supported that the bacteria can in fact protect against some illness such as acid reflux and asthma. However, extensive characterizing Oetzi Iceman’s H. pylori could also shed light on ancient human migration patterns. Specifically, modern strains of H. pylori are assigned to distinct populations based on their geographical heritage, originating from either ancestral Asian populations (AE1) or hybrids between North Africa and Europe (AE2).
Comparative whole genome analysis showed that Oetzi Iceman’s H. pylori genome has highest similarity to three apAsia2 H. pylori genomes from India, and further high-resolution analysis of ancestral motifs revealed a co-ancestral matrix, showing that H. pylori shares ancestry with Indian strains but also with most European strains. Low levels of H. pylori ancestry was shared with the AE2 ancestry, which was interesting to scientists as it suggests AE2 introgression into Europe after the Copper Age. This was later than what has been proposed previously by the scientific community. Ultimately, these findings showed that Oetzi Iceman had H. pylori with strong AE1 genetic Asian origins, suggesting that the AE2 bacteria from African heritage began arriving after the Copper Age of European civilization.