Researchers from Ohio State University and the University of Illinois Urbana-Champaign have found that antimicrobial peptides derived from Lactobacillus rhamnosus GG can effectively reduce Salmonella in chickens, offering a potential non-antibiotic alternative for improving food safety and combating antimicrobial resistance.
The study, published in Microbiology Spectrum and supported by the U.S. Department of Agriculture’s National Institute of Food and Agriculture, demonstrated that specific peptides—particularly P1, P2, and P4—were able to inactivate multiple Salmonella strains, including S. Typhimurium and S. Enteritidis. These peptides also showed effectiveness against other harmful bacteria such as E. coli, suggesting broad antimicrobial potential.
When tested in chickens, oral doses of P1 and P2 significantly lowered Salmonella levels in the cecum, reducing colonization by up to 2.2 logs. The treatment also decreased bacterial presence in the liver by 30 percent without affecting the birds’ weight or overall health. Importantly, the peptides remained stable after heat and enzyme exposure—conditions typical in commercial feed processing—making them feasible for real-world poultry production.
Unlike traditional antibiotics, which often disrupt gut health, these peptides preserved the balance of beneficial gut bacteria. Metagenomic analysis revealed that key microbes such as Lactobacillus and Bifidobacterium remained unaffected, while harmful gram-negative bacteria were selectively inhibited.
Microscopy and molecular modeling indicated that P1 and P2 attack bacterial membranes, a mechanism less prone to resistance development. Repeated testing confirmed no resistance formation even after multiple exposures.
The findings suggest that short peptides from Lactobacillus could become a valuable tool for poultry producers seeking safer, antibiotic-free methods to control bacterial infections. Continued research will focus on refining dosage, delivery through feed or water, and scaling up production for commercial use.
If future trials prove successful, antimicrobial peptides could play a key role in advancing sustainable poultry farming and reducing the risk of Salmonella-related foodborne illnesses while supporting global efforts to limit antibiotic dependence.
