Associations of streptococci and fungi amounts in the oral cavity with nutritional and oral health status in institutionalized elders: a cross sectional study
Abstract Background:Disruption of the indigenous microflora is likely to relate with frailty caused by undernutrition. However, relationship between undernutrition and oral flora, especially normal indigenous bacteria, is not obvious. The aim of this study was to elucidate the associations of nutritional and oral health conditions with bacteria and fungi prevalence in oral cavity of older individuals.Methods:Forty-one institutionalized older individuals with an average age ± standard deviation of 84.6 ± 8.3 years were enrolled in this study. Body mass index (BMI) and Oral health assessment tool (OHAT) were used to represent nutritional and oral health status. Amounts of total bacteria, streptococci, and fungi in oral specimens collected from the tongue dorsum were determined by quantitative polymerase chain reaction (PCR) assay results. Results:There found a significant correlation between BMI and streptococcal amount (ρ=0.526, p<0.001). In addition, the undernutrition group (BMI <20) showed a significantly lower average number of oral streptococci (p=0.003). In logistic regression models, streptococcal amount was the significant variable accounting for “not undernutrition” [odds ratio 5.68 and 95% confidential interval (CI) was 1.64-19.7 (p=0.06)]. On the other hand, participants with poor oral health condition (OHAT ≥5) harbored significantly higher level of fungi (p=0.028). Conclusion:Oral streptococci were associated with systemic nutritional condition and oral fungi were associated with oral health condition. Thus, it is necessary to examine oral indigenous bacteria as well as etiological microorganisms in order to understand the relationship of frailty with oral microflora in older individuals.