Researchers say bacteriophages are maturing as precision alternatives to antibiotics

Dr. David Pride of the University of California, San Diego, told the Council that bacteriophages are abundant and act on narrow bacterial targets, which could allow treatments that spare the broader microbiome. "There’s about 10 to the 13th particles of bacteriophages in the human gut alone," Pride said, explaining why introducing phage therapeutically is not introducing an unprecedented agent to patients.

Pride described "jumbo phages" (genomes >200 kb) with nucleus‑like structures that can broaden host range and resist bacterial defenses; his lab combines jumbo and non‑jumbo phages in cocktails to increase coverage. He gave organism‑specific examples—S. aureus, Klebsiella and Pseudomonas—where phage collections and coevolutionary methods have improved killing and raised thresholds for resistance.

Industry representatives said they are developing laboratory and computational pipelines to select cocktails and to monitor resistance. Panelists acknowledged phage resistance is a concern: both Ashley Trama (Locus Biosciences) and Pride said clinical trials include longitudinal sampling to detect emergence of resistance and that laboratory coevolution can increase resistance thresholds. They also said current lab standards (plaque assays, EOP) have limits and that new assays (e.g., ATP‑release approaches) are under study to standardize clinical susceptibility testing.

Speakers stressed delivery and indication specificity: for example, direct dosing at the infection site (intra‑urethral for UTIs, nebulization for respiratory infections) is often preferred. Panelists emphasized phage therapy remains an active research field with an expanding evidence base but that regulatory approval and trial evidence for routine indications are still needed.