The Importance of Ear Canal Microbiota and Earwax in the Prevention of Outer Ear Infections

This article describes the microbiome of the outer ear and the earwax in the ear canal, which performs various protective functions against bacterial infections. This article is based on an analysis of literature gathered from databases including PubMed, Google Scholar, Web of Science, and Scopus, primarily from the last 15 years. The search strategy included MeSH terms: ear canal, microbiome, earwax, cerumen, antibacterial peptides, ear infections, biofilm. Only peer-reviewed articles were included. The natural ear canal microbiota provides so-called colonization resistance, which protects against invasion by pathogenic microorganisms. Earwax is composed primarily of keratin secreted by epithelial cells and substances secreted by sweat and apocrine glands. It plays a key role in the physiology of the ear canal, maintaining a low pH, limiting moisture, and exhibiting antimicrobial properties. Both an excess and a deficiency of earwax can lead to dysbiosis of the outer ear, and consequently to the development of various infections. In an era of increasing antibiotic resistance and the search for new solutions in the fight against pathogenic microorganisms, understanding the natural properties of earwax is becoming increasingly important.