Despite phage therapy demonstrating success in various individual cases of antimicrobial resistance, a comprehensive and unequivocal demonstration of the therapeutic potential of phages remains to be shown.

The co-evolution of phages and their bacterial hosts resulted in several inherent limitations for the use of natural phages as therapeutics such as restricted host range, moderate antibacterial efficacy, and frequent emergence of phage-resistance.

These constraints can be overcome by leveraging recent advances in synthetic biology and genetic engineering to provide phages with additional therapeutic capabilities, improved safety profiles, and adaptable host ranges.

Loessner et al. examined different ways phages can be engineered to deliver heterologous therapeutic payloads to enhance their antibacterial efficacy and discuss their versatile applicability to combat bacterial pathogens. They concluded that engineered phage therapy will be an important complementary strategy to address the global antimicrobial resistance crisis.