Researchers cultured 250+ gut bacteria and found 134 "hidden" phages that could be awakened. Most stayed silent in the lab until exposed to human gut cells or complex bacterial communities.

That means phage activity depends on both the microbiome and the human host. Some phages have even lost the genes needed to reactivate, becoming permanent passengers.

This study gives us a powerful resource of real, testable phage-host pairs and shows that phages are active players shaping our gut ecosystem.

ARTICLE

Dahlman, Samuel, Tom O. Delmont, Alejandro Reyes, Anna L. Mallott, and Emily B. Hollister, et al. "Isolation, Engineering and Ecology of Temperate Phages from the Human Gut." Nature 638 (2025): 145-152. https://doi.org/10.1038/s41586-025-09614-7.