The mammalian gut microbiome relies on a delicate balance between bacteria and bacteriophages (phages). When a harmful pathogen like Salmonella is ingested, native phages are usually absent, and by the time the host falls ill, any phages present only manage a balance rather than eliminating the infection.

To address this, Virginia Tech researchers engineered a nonpathogenic E. coli bacterium that pre-loads phages in the gut as a prophylactic defense. Published in Nature Microbiology, their study demonstrated that this proactive approach successfully protected mice from Salmonella by destroying the pathogen upon entry.

A team led by researchers from the University of Osaka has revealed the first structure of an umami taste receptor. They found that the pufferfish receptor can sense many more amino acids than the human receptor, including some linked to flavors humans detect as sweet. This helps the fish to detect more types of savory chemicals in their food. The research also shows how the receptor’s structure makes this flexibility possible. The findings could help develop new umami flavors.