Table 1.

Benefits and challenges of different aspects of phage therapy.

Aspect of Phage Therapy	Benefit for Phage Therapy	Challenge for Phage Therapy
Specificity	Little or no interaction with natural beneficial microflora of the organism and environment	Narrow host range; not useful in case of systemic disease
Safety	Action against AMR strains; ability to adapt to changing environmental conditions (e.g., phage-resistant bacteria); biofilms destruction	Development of phage resistance; a risk of HTG; difficulty of lifecycle determination
Stimulation of immune response	Induction of immune response and resistance to bacterial infection	Clearance of phages from the organism by immune system
Formulation and administration	Self-dosing, able to replicate in in vivo conditions	A proper formulation needed to deliver bacteriophages to the site of infection
Bacteriophage abundance and stability	A lot of phages in the environment, easy to isolate, inexpensive	Sensitivity to various physico-chemical parameters resulting in instability of phages
Influence on the environment	Non-toxicity to humans, plants, animals and environment	Possibility of re-invasion of vacated niches by other bacterial species after eradication of pathogens
Regulatory/economic aspects	Growing research on phages in the entire world, a hope to replace antibiotics in a future	Still many black holes in knowledge about phages; absence of regulatory guidelines to become regular treatment