Microgravity reshapes phage–bacteria battles on the ISS

A Space.com study compared T7 phage infections of E. coli in identical setups on the ISS and on Earth. In microgravity, infection slowed at short incubation times due to reduced fluid mixing and host stress, but after 23 days the infection could still proceed with fewer bacteria. The research also found microgravity-specific mutations in the phage genome, suggesting space conditions steer phage–host evolution differently. These results have implications for spaceflight microbiology and potentially for Earth-based phage therapies, though more work is needed to assess long-term health risks for astronauts.