Phages with a broad host range are common across ecosystems.

Phages are diverse and abundant within microbial communities, where they play major roles in their evolution and adaptation. Phage replication, and multiplication, is generally thought to be restricted within a single or narrow host range. Here we use published and newly generated proximity-ligation-based metagenomic Hi-C (metaHiC) data from various environments to explore virus-host interactions. We reconstructed 4,975 microbial and 6,572 phage genomes of medium quality or higher. MetaHiC yielded a contact network between genomes and enabled assignment of approximately half of phage genomes to their hosts, revealing that a substantial proportion of these phages interact with multiple species in environments as diverse as the oceanic water column or the human gut. This observation challenges the traditional view of a narrow host spectrum of phages by unveiling that multihost associations are common across ecosystems, with implications for how they might impact ecology and evolution and phage therapy approaches.