Integrated analysis of the oral and intestinal microbiome and metabolome of elderly people with more than 26 original teeth: a pilot study.

Elderly subjects with more than 20 natural teeth have a higher healthy life expectancy than those with few or no teeth. The oral microbiome and its metabolome are associated with oral health, and they are also associated with systemic health via the oral-gut axis. Here, we analyzed the oral and gut microbiome and metabolome profiles of elderly subjects with more than 26 natural teeth. Salivary samples collected as mouth-rinsed water and fecal samples were obtained from 22 healthy individuals, 10 elderly individuals with more than 26 natural teeth and 24 subjects with periodontal disease. The oral microbiome and metabolome profiles of elderly individuals resembled those of subjects with periodontal disease, with the metabolome showing a more substantial differential abundance of components. Despite the distinct oral metabolome profiles, there was no differential abundance of components in the gut microbiome and metabolomes, except for enrichment of short-chain fatty acids in elderly subjects. Finally, to investigate the relationship between the oral and gut microbiome and metabolome, we analyzed bacterial coexistence in the oral cavity and gut and analyzed the correlation of metabolite levels between the oral cavity and gut. However, there were few associations between oral and gut for bacteria and metabolites in either elderly or healthy subjects. Overall, these results indicate distinct oral microbiome and metabolome profiles, as well as the lack of an oral-gut axis in elderly subjects with a high number of natural teeth.

Dysbiosis of oral microbiome persists after dental treatment-induced remission of periodontal disease and dental caries.

IMPORTANCE: We characterized the oral conditions, salivary microbiome, and metabolome after dental treatment by investigating the state after treatment completion and transition to self-care. Dental treatment improved oral health conditions, resulting in oral disease remission; however, the imbalanced state of the salivary microbiome continued even after remission. Although the results of this study are preliminary, owing to the small number of participants in each group when compared to larger cohort studies, they indicate that the risk of disease may remain higher than that of healthy participants, thereby demonstrating the importance of removing dental plaque containing disease-related bacteria using appropriate care even after treatment completion. We also identified bacterial species with relative abundances that differed from those of healthy participants even after remission of symptoms, which may indicate that the maturation of certain bacterial species must be controlled to improve the oral microbiome and reduce the risk of disease recurrence.

Effects of radiofrequency and ultrasound on the turnover rate of skin aging components (skin extracellular matrix and epidermis) via HSP47-induced stimulation.

Skin aging cannot be escaped, being due to both intrinsic and extrinsic stimuli. They lead to a reduced extracellular collagen matrix in the dermis, along with a higher degradation by metalloproteases (MMPs) activity, as well as a lower differentiation and function of epidermis keratinocytes, characterized by wrinkling and loss of skin elasticity. One of the recent technology to overcome this skin aging process is the use of radiofrequency (RF) and ultrasound (US) technologies which use thermal stimulation to induce neocollagenesis in the skin. But no explanations exist on the involved pathways. Our hypothesis is that RF-US generated heat increases the collagen formation via the heat shock protein 47 (HSP47) induction, a heat sensitive protein related to the collagen expression. To confirm this hypothesis, normal human skin substitutes were subjected to RF-US treatment and results were monitored after 24 and 44 h. RNA sequencing showed a significant induction for the genes related to the epidermis differentiation processes. Almost all keratin genes were thus found upregulated from 2 to 15 times, while collagen type XVII and collagen type IV were increased 12 and 5 times respectively. In parallel, most of MMP genes were observed downregulated. RF-US treatment significantly increased levels of HSP47 proteins, while collagen XVII proteins showed a tendency to be increased and glycosaminoglycans were found 1.4 times significantly enhanced. Finally, histology assessment showed a higher expression of cytokeratins 10 and 14 which can testify a possible reactivation of the skin proliferative state as a rejuvenation strategy.