LL-37 is a natural human peptide that can stop bacteria from forming sticky biofilms, which are hard to treat with antibiotics. It works even at low doses and also helps the immune system, making it a promising candidate for new anti‑infection treatments, though it’s still mostly in research stages.

Human pathogens often colonize their host by the formation of biofilms. These surface-attached aggregates of bacteria are characterized by a self-produced extracellular matrix, which makes them highly resistant towards antibiotic treatment. Their abilities to adhere to abiotic surfaces (e.g., catheters and other medical devices) also makes bacterial biofilm formation a challenge in modern medicine. Antimicrobial peptides have lately been introduced as a potential class of drug molecules for combating severe hospital-acquired infections. One of these peptides, human cathelicidin LL-37, has recently been demonstrated to bridge innate and adaptive host defence, in addition to facilitating a robust antibiofilm effect at sub-inhibitory concentrations. In this review we will discuss the evidence, potential and challenges for LL-37 as a candidate molecule for therapeutic use.