These researchers aim to characterize the microbiome of the human ear canal. Investigations into the human microbiome have dramatically improved understanding of disease pathophysiology and shaped clinical treatment options. There is a large gap in knowledge of the organisms commensal to the healthy ear, particularly in the external auditory canal and cerumen. In alignment with the efforts of the NIH Human Microbiome Project, establishing a reference standard for the microbiome of the healthy external ear canal is essential for higher understanding of various otologic disease states. This project will fill this need by establishing the first community-based and culture-independent assessment of the external ear canal microbiome and will identify demographic, behavioral, and other person-specific factors that influence strain abundance and bacterial diversity.
For this work, attendees of the 2022 Minnesota State Fair were enrolled and will be surveyed on demographic factors, ear hygiene habits, and medical history. A swabbed sample of the external ear canal, including any cerumen if present, was obtained and digital otoscopy subsequently performed to document cerumen status. DNA from each sample will be extracted and sequenced via the MiSeq platform. The present microbiota will be characterized using the UNITE taxonomy reference guide and in total this will highlight the predominant species as well as variations in alpha and beta microbial diversity. Potentially predictive factors, gathered via the survey, will be identified through multivariable analyses. This study will establish an important reference standard for the normal ear canal microbiome. In the future this reference will be used as a tool for identifying microbial changes in disease as well as a foundation for development of novel treatments such as probiotics or cerumen transplants.