Host life-history strategy is a critical determinant of virulent phage infection propensity.

Bacteriophages shape microbial communities through two major lifestyles: virulent (obligately lytic) and temperate (capable of lysogeny). Prevailing phage ecology frameworks focus on how environmental conditions, host density, and physiological state modulate infection modality. This perspective overlooks how host traits exert selective pressure on the distribution of virulent and temperate lifestyles across bacterial species, which limits understanding of phage ecology. To address this critical knowledge gap, we adopt a host-centric, trait-based perspective and use 5821 complete bacterial genomes to build a host life-history space predominantly defined by genome size, metabolic capacity, and growth rate potential. After mapping phage lifestyle association signals, prophage burden formed a continuous gradient across this space. Also, virulent phage association was positively correlated with prophage burden, revealing a nested structure of lifestyle signals. Functional trait analysis identified enrichment of resource-acquisition modules underlying both temperate and virulent associations. Overall, these findings indicate that phage lifestyle is significantly influenced by host life-history strategies, highlighting fast-growing, metabolically versatile hosts as favorable targets for virulent phage isolation and biocontrol applications.