A protein that helps fruit flies sleep has yielded a surprising lead in the fight against drug-resistant bacteria: tiny pieces of the protein can stop bacteria from growing in laboratory tests.
Researchers at the University of Tsukuba in Japan and collaborating institutions studied Nemuri, a sleep-inducing protein found in the fruit fly Drosophila melanogaster. Their work, published in Nature Communications, comes as bacteria that resist existing antibiotics continue to threaten health around the world. Finding compounds that work in a different way could help researchers build new options against infections that are increasingly hard to treat.
The team identified several short fragments of Nemuri, called Nemuri peptides. In tests, these peptides inhibited a wide range of microorganisms, including clinically important drug-resistant bacteria. They also killed Escherichia coli and Staphylococcus aureus at concentrations close to those needed to stop the bacteria from growing. E. coli and S. aureus are two well-studied bacterial species that can cause human infections.
The researchers looked at how the peptides worked inside bacterial cells. The peptides entered the cells and gathered in areas rich in RNA and ribosomes. Ribosomes are the cell structures that use genetic instructions to make proteins, which bacteria need to live and grow. The team found no substantial damage to bacterial outer membranes at the antimicrobial concentrations tested, suggesting the peptides were not simply bursting the cells open.
Instead, the peptides interacted with RNA and ribosome surfaces, causing ribosome-rich areas to reorganize into condensed regions. This change reduced ribosome movement and suppressed protein production across the cell. In effect, the peptides interfered with the machinery bacteria use to make many of the proteins they need to survive.
The study also found low toxicity toward cultured insect and mammalian cells. That is an encouraging early observation, but it does not show that the peptides are safe or effective as medicines. The experiments were conducted in laboratory tests, and the researchers say further work is needed, including tests in animal models of bacterial infection. Researchers would also need to examine safety and whether the peptides can work in a living body.
For now, Nemuri peptides are a starting point, not a treatment ready for patients. Their distinct way of disrupting bacterial protein production gives scientists a new path to investigate as antibiotic resistance grows. The next studies will need to show whether this fruit-fly-derived approach can move beyond lab dishes and prove useful against infections in animals—and, eventually, people.
The study, led by Suguru Nishinami and colleagues, is titled “Antimicrobial peptides derived from Nemuri induce ribosomal condensation to inhibit translation.” It appeared in Nature Communications in 2026 (DOI: 10.1038/s41467-026-78960-5).