Selective Human-Milk-Inspired Antimicrobial Peptides for the Treatment of Bacterial Vaginosis

Background: Antimicrobial resistance (AMR) is a global healthcare threat. Traditional largely non-selective antibiotics produce side effects due to the natural host microbiome being modified creating a loss in homeostasis. In women, AMR is a cause of acute generational impact. For example, bacterial vaginosis (BV), the most common gynecological infection in reproductive-age women, is a serious public health concern due to its high rates of recurrence, secondary infections, and reproductive issues; and two currently prescribed antibiotics for BV do not fully resolve the symptoms. Objective: The strong need for innovative, potent, safe, and selective therapeutics has prompted a search for such bioactive molecules in milk. Resulting from 200 million years of evolutionary pressure, mammalian lactation not only nourishes infants, but it has also been under relentless Darwinian selective pressure to provide protection from a variety of infections. Methods: Computationally designed human-milk-inspired peptides (AMPs) were tested in standard microbicidal assays for activity against BV pathogens, and evaluated for stability and safety. Results: Several AMPs are bactericidal towards Gardnerella vaginalis, a major BV-associated pathogen, and other BV-associated pathogens. Some novel AMPs do not impact the viability of key lactobacilli linked to a healthy vaginal microbiome. These stable, membrane-acting cationic AMPs reduce inflammation during an infection assay and are safe in EpiVag organoid tissues. Conclusions: AMPs can address concerns like non-selectivity and antibiotic resistance—thereby addressing AMR. Lead AMPs from this study offer a promising solution for the development of novel therapeutics for the treatment of BV, which may reduce the burden of AMR.