%0 Journal Article
%T Microbiome of the External Auditory Canal: Changes After Long-Term Hearing Aid Use.
%A Sjövall A
%A Mustanoja E
%A Lyyski A
%A Auvinen P
%A Silvola J
%A Aarnisalo A
%A Pätäri-Sampo A
%A Laulajainen-Hongisto A
%J Otol Neurotol
%V 45
%N 6
%D 2024 Jul 1
%M 38769078
%F 2.619
%R 10.1097/MAO.0000000000004198
%X <B>OBJECTIVE: </B>To investigate the microbial changes of long-term hearing aid use culture independently.<BR><B>METHODS: </B>Cross-sectional study.<BR><B>METHODS: </B>Fifty long-term hearing aid users and 80 volunteer controls with asymptomatic ears.<BR><B>METHODS: </B>External auditory canal (EAC) sampling with DNA-free swabs.<BR><B>METHODS: </B>Microbial communities in the samples were investigated with amplicon sequencing of the 16S rRNA gene.<BR><B>RESULTS: </B>The final analysis contained 48 hearing aid users, 59 controls. Twenty-four samples were excluded because of low sequence count, recent use of antimicrobials and/or corticosteroids, recent cold, or missing health status. The groups showed significant differences in bacterial diversity (beta div., p = 0.011), and hearing aid users showed lower species richness than the control group (alpha div., p < 0.01). The most frequent findings in both groups were Staphylococcus auricularis , Alloiococcus otitis , Cutibacterium acnes , Corynebacterium otitidis , and Staphylococcus unclassified sp. Hearing aid users' samples presented more Corynebacterium tuberculostearicum than the control samples. Common EAC pathogens, such as Staphylococcus aureus or Pseudomonas aeruginosa were rare.<BR><B>CONCLUSIONS: </B>Long-term hearing aid use lowers bacterial diversity and modulates the EAC microbiome. The changes mostly affect commensals. Lowered diversity may predispose individuals to EAC conditions and needs more research.