Oral Microbiome Changes During Hospitalization in Older Adults Not Receiving Mechanical Ventilation

Oral bacteria can be pathogenic and may change during hospitalization, potentially increasing risk for complications for older adults, including residents of skilled nursing facilities (SNFs).

To compare the oral microbiome at hospital admission by prehospital residence (SNF vs home) in older adults not receiving mechanical ventilation and to assess changes in their oral microbiome during hospitalization.

This prospective, observational study included 46 hospitalized adults (≥65 years old) not receiving mechanical ventilation, enrolled within 72 hours of hospitalization (15 admitted from SNF, 31 from home). Oral health was assessed with the Oral Health Assessment Tool at baseline and days 3, 5, and 7. Genomic DNA was extracted from unstimulated oral saliva specimens for microbiome profiling using 16S ribosomal RNA sequencing. Taxonomic composition, relative abundance, α-diversity (Shannon Index), and β-diversity (Bray-Curtis dissimilarity) of bacterial communities were determined.

Most patients were female (70%) and White (74%) or Hispanic (11%). Mean age was 78.7 years. More patients admitted from SNFs than from home had cognitive impairment (P < .001), delirium (P = .01), frailty (P < .001), and comorbidities (P = .04). Patients from SNFs had more oral bacteria associated with oral disease, lower α-diversity (P < .001), and higher β-diversity (P = .01). In the 28 study completers, α-diversity altered over time (P < .001). A significant interaction was found between groups after adjusting for covariates (P < .001).

Hospitalized older adults admitted from SNFs experience oral microbial and oral health disparities.