Antimicrobial Peptides LL-37 and Lactoferricin Boost Antibiotic Power Against Oral Biofilms

Researchers grew two types of polymicrobial biofilms in vitro: facultative anaerobic (representing caries-associated bacteria) and obligate anaerobic (representing periodontal disease-associated bacteria). They tested LL-37 and human lactoferricin alone and in combination with amoxicillin, clindamycin, and metronidazole, measuring biofilm reduction and bacterial viability.

Oral infections like periodontitis affect billions worldwide, and biofilm-forming bacteria are notoriously resistant to antibiotics. Rather than developing new antibiotics, this approach uses the body's own antimicrobial peptides to make existing antibiotics more effective. This 'combination therapy' strategy could address antibiotic tolerance without contributing to antibiotic resistance.

Antimicrobial resistance is a global health crisis, and biofilm infections are among the hardest to treat. LL-37 and lactoferricin are natural components of human innate immunity, and leveraging them to enhance antibiotic efficacy represents a promising 'adjuvant' approach. This concept extends beyond dentistry to any biofilm-associated infection, including wound infections, device-related infections, and chronic lung infections.

This is an in vitro study using laboratory-grown biofilms, which may not fully replicate the complexity of oral biofilms in the human mouth. The biofilm models used only 3 bacterial species each, while real oral biofilms contain hundreds of species. Peptide stability in saliva and the oral environment was not assessed. No in vivo or clinical data were generated. Cost and delivery challenges of antimicrobial peptides in clinical dental practice were not addressed.