Antimicrobial Peptides from Probiotic Bacteria Could Fight Drug-Resistant Infections in Newborns

The review identifies LAB-derived bacteriocins as promising antimicrobial agents against MDR neonatal sepsis pathogens, with several key advantages: narrow-spectrum activity that spares beneficial microbiota, biocompatibility particularly important for immunocompromised newborns, and favorable physicochemical properties including thermal stability, enzymatic resistance, and pH tolerance. Milk-derived LAB strains are highlighted as particularly relevant given breast milk's natural protective functions for newborns. Current evidence is primarily in vitro, with clinical trials needed.

Narrative review compiling current literature on LAB-derived bacteriocins, covering their in vitro antimicrobial activity against MDR neonatal sepsis pathogens, molecular diversity, mechanisms of action, physicochemical properties, and clinical potential.

Neonatal sepsis is a leading cause of newborn death worldwide, and antibiotic resistance is making it harder to treat. Newborns are uniquely vulnerable because their immune systems are immature and their microbiomes are still developing. Bacteriocins from milk-associated bacteria could provide a natural, microbiome-friendly antimicrobial strategy — potentially as supplements, topical agents, or adjuncts to antibiotics in NICUs.

The antimicrobial resistance crisis is particularly devastating for neonatal medicine, where treatment options are already limited. Bacteriocins represent a paradigm shift — using peptides from the bacteria that naturally colonize and protect newborns. This connects to the broader movement toward microbiome-conscious medicine, where treatments are designed to work with rather than against the body's natural microbial communities.

The evidence is almost entirely in vitro — no clinical trials of bacteriocins for neonatal sepsis have been reported. Production scale-up and pharmaceutical formulation challenges are acknowledged but not solved. Narrow-spectrum activity, while beneficial for the microbiome, could be a limitation if the causative pathogen isn't identified quickly. Regulatory pathways for peptide-based antimicrobials in neonates are unclear. The review may overstate readiness for clinical application given the early stage of research.