Association between oral frailty and Prevotella percentage in the oral microbiota of community‐dwelling older adults who participated in the CHEER Iwamizawa project, Japan

Abstract Background Prevotella bacteria are associated with inherent diseases of the oral cavity, such as periodontal disease, and systemic diseases. Oral frailty (OF) has been associated with nursing necessity and death. However, the relationship between OF and oral microbiota has not been fully clarified. Objective This cross‐sectional study investigated the association between OF and Prevotella percentage in the oral microbiota of community‐dwelling older adults. Methods Oral bacteria species from saliva were identified in 208 community‐dwelling older individuals aged ≥60 years in Japan. The proportion of Prevotella in the oral microbiota was classified into three tertile groups, and its relationship with each test item for OF (number of remaining teeth, masticatory performance, oral diadochokinesis, tongue pressure, difficulties eating tough foods, difficulties swallowing tea or soup, number of applicable OF judgement items, and existence of OF) was examined using ordinal logistic regression analysis. Results The Prevotella proportions were classified into lower, middle and upper groups, comprising 70, 69 and 69 participants, respectively. The three groups showed a significant relationship between the number of remaining teeth (odds ratio [OR]: 0.946, 95% confidence interval [CI]: 0.915–0.977), masticatory performance (OR: 0.897, 95% CI: 0.844–0.953), number of applicable OF judgement items (OR: 1.477, 95% CI: 1.14–1.915), and existence of OF (OR: 4.194, 95% CI: 1.519–11.576). Conclusion The proportion of Prevotella in oral microbiota was high in individuals with OF. Among the older adults, the type of oral microbiota and systemic diseases may be related to the examination and management of oral function decline.