Oral Care Strategies to Suppress Salivary Bacterial Growth for the Prevention of Aspiration Pneumonia in Older Individuals Requiring Long-Term Care.

Japan's aging population faces a significant gap between life expectancy and healthy life expectancy, during which many older adults require long-term care and are at high risk of aspiration pneumonia, a leading cause of death. Aspiration pneumonia arises from the interaction of saliva-borne bacteria, aspiration events, and immune decline. Toothbrushing, while essential for oral health, may transiently increase bacterial counts, especially in those unable to rinse or gargle. Combining brushing with moisturizing gel and povidone-iodine gel effectively suppresses bacterial load, reducing pneumonia risk. Tailored oral care based on swallowing function, along with maintaining oral function through dental treatment, is crucial to prevent aspiration pneumonia in older adults requiring nursing care. This review highlights that increased salivary bacterial load, a key factor in pneumonia risk, is more strongly linked to reduced oral function (e.g., decreased tongue pressure and swallowing ability) than to poor oral hygiene alone.