In this week's Science, an international team of researchers reports the results of an analysis of microbes from the gut of a 5,300-year-old European glacial mummy, which provides new insights into ancient human migration. Given Helicobacter pylori's prevalence as a human pathogen, various strains of the stomach bacterium have evolved as humans have migrated around the world. In their study, the investigators took samples from the ancient man's gut and analyzed them for H. pylori. They found a single strain that not only was producing virulent factors, suggesting the man was ill the day he died, but also shared a high level of ancestry with prehistoric Indian strains and most modern European strains, but very little ancestry with North African strains. Modern-day European strains, in contrast, also have a high level of ancestry with North African strains, suggesting that African populations arrived in Europe in the past few thousand years. GenomeWeb has more on this study here.
And in Science Signaling, the journal's editors have named their breakthroughs of 2015. These include microbial fuel cells, insights into the roles of exosomes in cancer metastasis, a mediator of apoptosis, and molecular targets for malaria.