Aging and periodontitis increase brain dissemination of oral bacteria

Aging may increase the periodontitis-induced changes in the oral and systemic microbiome, which an altered inflammatory response may accompany. Experimental periodontitis was created in old and young mouse models. Bone loss, senescence, and inflammatory gene expression and serum inflammatory markers were assessed in each model, and oral, brain, and gut microbial content was analyzed. Senescence and inflammatory markers were higher in old mice than in young ones, and periodontitis increased their expression. Our results suggested that aging and periodontitis may contribute to the dissemination of oral bacteria to the brain.