Critical Care volume 29,
Article number: 320, Published: 23 July 2025
Abstract
Background
Ventilator-associated pneumonia (VAP) after tracheal
intubation is a major infectious complication in patients in the intensive care
unit (ICU), with an incidence of 8–28%. Oral care in the ICU is essential;
however, the presence of an intubation tube and restricted mouth opening cause
complications. A healthy commensal microflora in the oral cavity resists
colonization by respiratory pathogens, and poor oral hygiene may increase the
risk for VAP. In this study, we examined the effectiveness of oral care on oral
bacterial counts and microbial diversity in patients admitted to the ICU.
Methods
Fifteen ICU patients were included in this study. Oral
microbiome samples were collected by swabbing the surface of the tongue. Oral
bacterial counts were measured at four time points: before and after oral care,
both pre- and post-extubation. Additionally, microbiome analysis was conducted
twice: once before oral care pre-extubation, and once before oral care
post-extubation. Oral bacterial counts were assessed using a bacterial counter,
and microbiome analysis was performed through 16S rRNA gene amplicon sequencing.
Results
Oral bacterial counts significantly decreased after oral
care at both pre- and post-extubation time points. Microbiome analysis revealed
significant differences in alpha diversity pre- and post-extubation samples.
Samples post extubation were less diverse.
Conclusions
This study demonstrates that oral care effectively reduces
bacterial counts in ICU patients, both pre- and post-extubation. Microbiome
analysis revealed shifts in microbial diversity, suggesting that the oral
microbiota was disrupted during intubation. Given the risk of VAP, oral care
may play an important role to prevent VAP in ICU settings.
