Early Insights Into the Healthy Laryngeal Microbiome: A Pilot Study Evaluating Salivary and Oropharyngeal Sampling as...

The microbiome plays a critical role in health and disease. While the oral cavity microbiome is well-characterized, the healthy laryngeal microbiome remains underexplored despite its unique immunological role. Laryngeal sampling is more invasive, time-consuming, and costly than salivary and oropharyngeal sampling. Understanding microbial differences between sites can help optimize sampling strategies.

Nineteen individuals undergoing otolaryngologic surgery for non-oral or laryngeal disease were included. Matched saliva, oropharyngeal swabs, and laryngeal swabs were collected. DNA was extracted, and the V3/V4 region of the 16S rRNA gene was amplified and sequenced using Illumina NextSeq 2000. Amplicon sequence variants were identified via DADA2, and taxa were classified using a hybrid alignment/naïve Bayes approach. Microbial diversity was assessed using alpha and beta diversity measures.

Among 19 participants (31.6% female, mean age 61), most identified as Spanish, Hispanic, or Latino (36.8%). No significant differences were found in taxa diversity between the saliva, oropharynx, and larynx. Core microbiomes shared 13 taxa, with unique taxa in saliva and larynx. While unadjusted comparisons showed that some taxa were differentially abundant between the saliva and the larynx, these differences did not remain significant after correction for multiple comparisons using false discovery rate. Microbiome composition did not predict sample site.

While both salivary and oropharyngeal samples showed similar taxonomic diversity to the larynx, the oropharynx is a superior surrogate, sharing more core taxa, and lacking unique core taxa of its own. The oropharynx could represent a cost-effective alternative for microbiome diagnostics, enhancing patient comfort and clinical feasibility without compromising insights.

Level 3-small prospective cohort study.