Enrichment of Eubacterium Nodatum and Olsenella Is Associated with Disease Severity in Iatrogenic Subglottic Stenosis

Introduction: The pathogenesis of iatrogenic subglottic stenosis (IS) involves aberrant inflammation and impaired wound healing following endotracheal intubation or tracheostomy. Although ischemic mucosal injury–associated dysbiosis has been implicated, the role of the local subglottic microbiome in disease development and severity remains poorly defined.

Methods: A prospective study was conducted using 64 subglottic mucosa samples from 29 treatment-naive IS patients and 35 patients undergoing otolaryngological surgery unrelated to laryngeal diseases (01/2023 - 09/2025). DNA was extracted and amplified, targeting the V3/V4 region of the 16S rRNA gene, followed by paired-end 2×300 bp sequencing on the Illumina NextSeq 2000. Amplicon sequence variants were identified via DADA2 and assigned to genera using a naive Bayes classifier.

Results: Gender (58.7% male IS, 58.8% controls) and age (50.7 IS, 52.4 control) did not differ between IS and control groups (p>0.05). IS patients’ core laryngeal microbiomes had similar alpha diversity compared to controls but uniquely contained Corynebacterium (12.43%; 95% CI: 4.84-20.03%), Aggregatibacter (7.06%; 95% CI: 0.00-14.26%), and Fusobacterium (3.79%, 95% CI: 1.66 -5.91%). IS samples were significantly enriched in Olsenella (3.03, p=0.002), Anaeroglobus (2.19, p= 0.02), Peptoniphilus (2.18, p= 0.04), Abiotrophia (1.91, p= 0.01), Tannerella (1.58, p= 0.02), Bergeyella (1.13, p= 0.02), and Eubacterium nodatum group (1.04, p= 0.05). Of these, Eubacterium nodatum group (0.05, q=0.03) and Olsenella (0.51, q=0.01) significantly increased with each increased Cotton-Myer grade.

Conclusions: This study identifies Eubacterium nodatum and Olsenella as taxa enriched in IS that are also associated with increasing disease severity. These organisms have been implicated in host inflammatory signaling (TLR 2 and 4) in periodontal disease, COPD, pneumonia, and cancer. Together, these findings demonstrate pro-inflammatory microbiome profiles in IS that may contribute to disease progression beyond that of mechanical injury alone.