Cross-sectional pilot study of relationships between specific oral bacteria and acute respiratory failure requiring intensive care unit admission

OBJECTIVES: Acute respiratory failure (ARF) is a severe condition requiring intensive care unit (ICU) admission. Periodontal disease is a chronic inflammatory disorder caused by periodontal bacteria, though it is unknown whether specific periodontal bacteria are associated with ARF patients admitted to the ICU. The present study was conducted to compare oral environmental factors and numbers of specific oral bacteria between patients with and without ARF related to ICU admission. METHODS: A cross-sectional investigation was performed with 64 ICU patients, divided into ARF (n = 18) and non-ARF (n = 46) groups based on the causative disease related to admission. Clinical characteristics, oral environment factors, and numbers of 12 oral bacterial species in saliva and tongue samples were examined using a DNA chip. RESULTS: Dry mouth and coated tongue were more frequently found in the ARF than the non-ARF group. The numbers of Porphyromonas gingivalis in both saliva and tongue samples in the ARF were greater than those in the non-ARF (p = 0.013, p = 0.028, respectively). The numbers of Capnocytophaga gingivalis from the tongues in the ARF group were greater as compared with those in the non-ARF group (p = 0.032). CONCLUSIONS: The findings obtained in this pilot study indicate the possibility that P. gingivalis and C. gingivalis are associated with ARF requiring ICU admission. CLINICAL SIGNIFICANCE: The oral microbiota may differ between ARF patients and non-ARF patients.