Tracking the evolution and persistence of antibiotic resistance in the human gut

Bacterial resistance to antibiotics is a growing health threat, but its evolution outside laboratory settings is poorly understood. Bacteria living in the human gut are now found to evolve persistent resistance after brief exposure to antibiotics, and factors that promote this evolution have been identified, highlighting the gut as a potential hotspot for this process. A genomic study of gut microbes during antibiotic use finds selective sweeps in a DNA gyrase gene that drive resistance.