LL-37, the only human cathelicidin antimicrobial peptide, plays multiple roles in oral immunity — fighting microbes, regulating inflammation, promoting wound healing — and its altered expression is linked to periodontitis, cavities, and oral cancer.
Only human cathelicidin peptideLL-37 is the sole cathelicidin antimicrobial peptide in the human body, making it uniquely important for innate immune defense in the oral cavity against bacteria, with additional roles in inflammation, wound healing, and cancer.
What the researchers found
LL-37 is expressed by gingival epithelium, salivary glands, and inflammatory cells in the oral cavity. Beyond direct antimicrobial killing, it modulates inflammatory responses, promotes wound healing, and influences cell proliferation and blood vessel formation. Altered LL-37 expression has been associated with periodontitis, dental caries, endodontic infections, and oral squamous cell carcinoma. The review positions LL-37 as both a potential diagnostic biomarker and therapeutic target in oral pathology.
Why it matters
Oral diseases including periodontitis and dental caries affect billions of people worldwide. Current treatments focus on mechanical removal of bacteria (brushing, scaling) and antibiotics. Understanding how the body's own antimicrobial peptide system works — and fails — in the mouth could lead to fundamentally different treatment approaches: boosting natural LL-37 production, using synthetic LL-37 analogs as therapeutics, or using LL-37 levels as early disease biomarkers.
How the study worked
Narrative review with comprehensive literature searches across PubMed, Scopus, and Google Scholar. Included in vitro, in vivo, and clinical studies evaluating LL-37 expression, mechanisms of action, and pathological implications in oral tissues.
What this study cannot tell us
This is a narrative review without systematic methodology, so study selection may be subject to bias. The evidence linking LL-37 alterations to specific oral diseases is largely associative rather than causal. Most mechanistic studies are in vitro or in animal models. Clinical applications of LL-37 in dentistry remain theoretical — no LL-37-based oral therapies or diagnostic tests have been validated in clinical trials.
How to read the evidence
This is a narrative review synthesizing in vitro, animal, and clinical evidence. While comprehensive, the review methodology is not systematic and the strength of evidence varies significantly across the different oral diseases discussed. Most therapeutic potential remains theoretical.
When this study was published
Published in 2026, this is a very current review capturing the latest understanding of LL-37's roles in oral health and disease.
The bigger picture
LL-37 research is one of the most active areas in antimicrobial peptide science. While much work has focused on its role in skin defense and systemic infections, this review consolidates its oral-specific functions. As antibiotic resistance grows and the limitations of mechanical dental care become apparent, peptide-based approaches to oral health — from antimicrobial mouthwashes to diagnostic saliva tests — represent a promising frontier.
Questions still open
- Could LL-37-based mouth rinses or gels serve as effective adjuncts to standard periodontal therapy?
- Is salivary LL-37 level a reliable early biomarker for periodontitis or oral cancer?
- What factors (genetics, diet, microbiome composition) regulate LL-37 expression in oral tissues, and can they be modified?
Common questions
What is LL-37 and why is it important for your mouth?
Could LL-37 be used to treat gum disease?
Read the original research
LL-37 antimicrobial peptide: Molecular characterisation and its role in oral health and disease-A narrative review.
Archives of oral biology, 183, 106516
Citation
Soman, Drisya; P, Jayanthi; Cm, Mahesh; Radhakrishnan, Rahul. (2026). LL-37 antimicrobial peptide: Molecular characterisation and its role in oral health and disease-A narrative review.. Archives of oral biology, 183, 106516. https://doi.org/10.1016/j.archoralbio.2026.106516