Lysozyme is an enzyme naturally present in various secretions such as saliva, tears, and mucus, and is well-known for its antimicrobial properties. It functions primarily by breaking down the peptidoglycan layer of bacterial cell walls, particularly those of Gram-positive bacteria, thereby acting as a first-line defense mechanism on mucosal surfaces. Scientific studies have demonstrated that lysozyme contributes to the innate immunity of mucus membranes by directly attacking and lysing pathogenic bacteria, thus supporting the integrity and health of tissues such as the oral, nasal, and respiratory mucosa. In clinical and laboratory settings, lysozyme has been shown to reduce bacterial load and modulate inflammatory responses on these surfaces.

Supplementation or topical application of lysozyme has been investigated in some studies, particularly for its potential to enhance mucosal immunity or manage infections. For example, lysozyme-enriched lozenges or sprays have been evaluated for oral health, with some evidence of reduced bacterial colonization and improved mucosal health. However, the overall clinical evidence remains moderate, with a limited number of controlled human trials directly linking lysozyme supplementation to significant improvements in mucus membrane health. Most of the support comes from mechanistic studies, animal models, or limited human data, rather than large, robust clinical trials. Therefore, while the scientific rationale is sound and there is moderate evidence supporting its use, more research is needed to fully validate its clinical efficacy for supporting the mucus membranes.