Peptide antibiotics are small proteins that can kill or inhibit the growth of bacteria. They are part of the innate immune system in many organisms, including humans, and are effective against a wide range of pathogens. These antibiotics work by disrupting bacterial cell membranes or interfering with essential cellular processes. Due to rising antibiotic resistance, researchers are exploring peptide antibiotics as potential alternatives to traditional antibiotics. Examples include defensins and cathelicidins, which are naturally occurring in various species. Their unique mechanisms of action make them promising candidates for new treatments against resistant bacterial infections.