Bacteriophages as Potential Anti-Pathogenic Agents for Intestinal Health of Weaned Piglets in the Post-Antibiotic Era: An Updated Review.

Background: The use of in-feed antibiotics was banned in numerous countries within the animal production industry as a result of the emergence of antibiotic-resistant bacteria and the presence of residual antibiotics. Bacteriophages, which are viruses that infect host bacterial cells, are considered the natural predators of bacteria. Over the past two decades, bacteriophages have garnered increasing attention for their potential in controlling pathogenic bacteria in weaned piglets.

Aims: The aim of this overview was to update the progress of bacteriophage application in weaned piglets.

Methods: For the section on bacteriophage application in weaned piglets, a systematic search was performed to identify relevant articles published before June 2025 in databases such as Web of Science.

Results: In this review, we provide a brief overview of bacteriophages, followed by a summary of the isolation of specific bacteriophages in weaned piglets. In addition, we have summarized the application progress of bacteriophages in weaned piglets, including the effects of oral administration or dietary supplementation with bacteriophages on growth performance, diarrhea characteristics, intestinal morphology, intestinal pH, nutrient digestibility, inflammatory response, intestinal barrier function, and intestinal microecology.

Conclusions: This updated overview novelly highlights the potential of bacteriophages as anti-pathogenic agents in mitigating infections caused by pathogenic bacteria in weaned piglets. This review could provide a scientific basis for controlling pathogenic bacteria infections in weaned piglets in the post-antibiotic era.