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.

Comparison of oral metabolome profiles of stimulated saliva, unstimulated saliva, and mouth-rinsed water.

Saliva includes a substantial amount of biological information, which has enabled us to understand the relationship between oral metabolites and various oral and systemic disorders. However, collecting saliva using a controlled protocol is time-consuming, making saliva an unsuitable analyte in large cohort studies. Mouth-rinsed water (MW), the water used to rinse the mouth, can be collected easily in less time with less difference between subjects than saliva and could be used as an alternative in oral metabolome analyses. In this study, we investigated the potential of MW collection as an efficient alternative to saliva sample collection for oral metabolome profiling. MW, stimulated saliva, and unstimulated saliva were collected from 10 systemically healthy participants. The samples were subjected to metabolome analysis using capillary electrophoresis time-of-flight mass spectrometry, and the types and amounts of metabolites in the samples were compared. Qualitatively, MW contained the same metabolites as unstimulated and stimulated saliva. While the quantity of the metabolites did not drastically change between the sampling methods, all three reflected individual differences, and the features of MW were the same as those of the unstimulated saliva. Overall, these results suggest that MW may be an appropriate alternative to saliva in oral metabolome profile analysis.

Comparison of oral microbiome profiles in stimulated and unstimulated saliva, tongue, and mouth-rinsed water.

Epidemiological studies using saliva have revealed relationships between the oral microbiome and many oral and systemic diseases. However, when collecting from a large number of participants such as a large-scale cohort study, the time it takes to collect saliva can be a problem. Mouth-rinsed water, which is water that has been used to rinse the oral cavity, can be used as an alternative method for collecting saliva for oral microbiome analysis because it can be collected in a shorter time than saliva. The purpose of this study was to verify whether mouth-rinsed water is a suitable saliva substitute for analyzing the oral microbiome. We collected samples of mouth-rinsed water, stimulated saliva, unstimulated saliva, and tongue coating from 10 systemic healthy participants, and compared the microbial diversity and composition of the samples using next-generation sequencing of 16S rRNA-encoding genes. The results showed that the microbial diversity of mouth-rinsed water was similar to that of unstimulated and stimulated saliva, and significantly higher than that of tongue-coating samples. The microbial composition at the species level of mouth-rinsed water also showed a very high correlation with the composition of unstimulated and stimulated saliva. These results suggest that the mouth-rinsed water is a suitable collection method instead of saliva for oral microbiome analysis.

Creation of New Functions by Combination of Surfactant and Polymer - Complex Coacervation with Oppositely Charged Polymer and Surfactant for Shampoo and Body Wash.

The combination of polymers and surfactants is an important means to create various functions in recent detergents and personal care products. In particular, detergents mixing oppositely charged anionic surfactants and cationic polymers induce coacervation by the dilution of the washing and rinsing process, and the complexes effectively adsorb onto surfaces and can change their characteristics. The driving force of the coacervation is electrostatic interaction between the anionic groups of the surfactant and the cationic groups of the polymer. Normally, the coacervation is controlled by selecting the molecular structure or the amount of polymer and surfactant. In shampoo and body wash compositions, we studied the complex precipitation (CP) regions and the morphology and rheological properties of precipitated complexes by focusing on the number of ionic groups in the anionic surfactants and cationic polymers, the mixed electrolyte and the ionic strength as a whole. This clarified the factors related to complex functions. For coacervation in shampoo based on alkyl ethoxylate sulfate (AES), the degree of cationization of the cationic cellulose (CC) and coexisting electrolyte greatly contributed to these functions. In a combination of moderately cationically charged CC and AES mixed amphoteric surfactant, the precipitated complexes became a loose mesh-like morphology, which was also formed when the charge shielding effect was enhanced by adding electrolyte. The precipitated complexes with a looser mesh-like morphology gave a smooth texture to the hair surface during rinsing.On the other hand, for coacervation in body wash based on fatty acid salt, the complexes were effectively precipitated in a combination with a synthetic polymer, poly diallyldimethylammonium chloride (PDADMAC), which has a higher cationic charge than CC. The precipitated complexes had high adsorbability onto skin and contributed to a moisturizing effect by lowering transepidermal water loss (TEWL).In this review, we introduce the controllable factors of coacervation in shampoo and body wash systems by focusing on the relationship between dilution processes and precipitation behavior.

Membrane permeation of giant unilamellar vesicles and corneal epithelial cells with lipophilic vitamin nanoemulsions.

Nanoemulsions of a lipophilic vitamin, retinol palmitate (vitamin A; VA), have a therapeutic effect on corneal damage. The nanoemulsion based on a triblock-type polymer surfactant with polyoxyethylene and polypropylene, EO100PO70EO100 (EOPO) showed superior efficacy, as compared with a nanoemulsion based on polyoxyethylene (60) hydrogenated castor oil (HCO). We studied the mechanism of VA nanoemulsions related to efficacy from the viewpoint of the interaction with plasma membrane-mimicking giant unilamellar vesicles (GUVs) and the plasma membrane permeation in corneal epithelial cells. When nanoemulsions and GUVs doped with fluorescent compounds were mixed each other, and observed by confocal laser microscopy, EOPO nanoemulsions induced endocytic morphological changes like strings and vesicles of the bilayer drawn inside a GUV by budding. Judging by isothermal titration calorimetry and ζ potential measurements, the EOPO nanoemulsions seemed to have stronger hydrophobic interactions with the lipid bilayer because of lower coverage of the core interface. Next, when the nanoemulsions prepared with a pyrene derivative of retinol (VApyr) were applied to corneal epithelial cells, the EOPO nanoemulsions greatly permeated the cells and gathered around the cell nucleus, as compared with HCO nanoemulsions. Furthermore, according to the three-dimensional images of the cell, it was found that the vesicles that absorbed nanoemulsions formed from the plasma membrane as real endocytosis, and were transported to the area around the nucleus. Consequently, it is likely that EOPO nanoemulsions entered the cell by membrane-mediated transport, delivering VA to the cell nucleus effectively and enhancing the effects of VA.