Project description:The effect of oral microbiota on the intestinal microbiota has garnered growing attention as a mechanism linking periodontal diseases to systemic diseases. However, the salivary microbiota is diverse and comprises numerous bacteria with a largely similar composition in healthy individuals and periodontitis patients. Thus, the systemic effects of small differences in the oral microbiota are unclear. In this study, we explored how health-associated and periodontitis-associated salivary microbiota differently colonized the intestine and their subsequent systemic effects by analyzing the hepatic gene expression and serum metabolomic profiles. The salivary microbiota was collected from a healthy individual and a periodontitis patient and gavaged into C57BL/6NJcl[GF] mice. Samples were collected five weeks after administration. Gut microbial communities were analyzed by 16S ribosomal RNA gene sequencing. Hepatic gene expression profiles were analyzed using a DNA microarray and quantitative polymerase chain reaction. Serum metabolites were analyzed by capillary electrophoresis time-of-flight mass spectrometry. The gut microbial composition at the genus level was significantly different between periodontitis-associated microbiota-administered (PAO) and health-associated oral microbiota-administered (HAO) mice. The hepatic gene expression profile demonstrated a distinct pattern between the two groups, with higher expression of Neat1, Mt1, Mt2, and Spindlin1, which are involved in lipid and glucose metabolism. Disease-associated metabolites such as 2-hydroxyisobutyric acid and hydroxybenzoic acid were elevated in PAO mice. These metabolites were significantly correlated with Bifidobacterium, Atomobium, Campylobacter, and Haemophilus, which are characteristic taxa in PAO mice. Conversely, health-associated oral microbiota were associated with higher levels of beneficial serum metabolites in HAO mice. The multi-omics approach used in this study revealed that periodontitis-associated oral microbiota is associated with the induction of disease phenotype when they colonized the gut of germ-free mice.
Project description:The postnatal microbiota-immune axis establishes lifelong homeostasis at mucosal epithelial barriers. However, whether barrier-specific physiological activities regulate this process remains ill-defined. During weaning, the oral epithelium, which is monitored by Langerhans cells (LCs), is challenged by the development of a microbial plaque and the initiation of masticatory forces capable of damaging the epithelium. We demonstrate that microbial colonization following birth facilitates the differentiation of oral LCs, setting the stage for the weaning period, where adaptive immunity develops. Despite the presence of the challenging microbial plaque, LCs mainly respond to masticatory mechanical forces, inducing adaptive immunity to maintain epithelial integrity that is also associated with bone loss. Unlike adult life, this bone loss is IL-17-independent, suggesting that the establishment and maintenance of oral mucosal homeostasis involve distinct mechanisms. Moreover, barrier-specific features play a fundamental role in this early-life process.
Project description:Background: Hypertension is one of the most common metabolic diseases in the elderly and its pathogenesis is associated with microbiota dysbiosis. Recent evidence suggests that oral microbiota dysbiosis is also an important factor in the development of hypertension. However, the relationship between hypertension and oral flora in the elderly has not been adequately investigated. Objective: The aim of this cross-sectional study was to investigate the structure of the oral microbiota and its correlation with hypertension in elderly hypertensive patients. To provide new ideas for the prevention and treatment of hypertension. Methods: 206 subjects aged 60 ~ 89 years were selected and divided into normal (CON) and hypertensive (HTN) groups, according to the 2018 Chinese Guidelines for the Management of Hypertension. The oral microbiome composition of saliva samples was determined by 16S rRNA gene sequencing. Results: Although there was no significant difference in α and β diversity between the two groups, systolic and diastolic blood pressure were the most important factors influencing the structure of the oral microbiota. At the phylum level, the relative abundance of the spirochete phylum and the mutualistic bacterial phylum was higher in the HT group than in the CON group (p < 0.05). Diastolic blood pressure was negatively correlated with Streptococcus. Furthermore, we analyzed HTN patients with 120 mmHg<systolic blood pressure<160 mmHg and systolic blood pressure>160 mmHg separately and found that the abundance of Saccharibacteria_(TM7) was significantly increased in the HTN_2 group. Conclusions: Our study identified specific oral microbiota in elderly hypertensive patients, confirming the relationship between oral microbiota and hypertension. This enhances our understanding of the important role of oral microbiota in the pathogenesis of hypertension and accumulates more evidence for microbial involvement in the development of hypertension.
Project description:Collectively, viruses are the principal cause of cancers arising in patients with immune dysfunction, including HIV+ patients. Kaposi’s Sarcoma (KS) etiologically linked to KSHV continues to be the most common AIDS-associated tumor. The involvement of oral cavity represents one of the most common clinical manifestations of this tumor. HIV infection incurs an increased risk for periodontal diseases and oral carriage from a variety of pathogenic bacteria. In the current study, by using 16S rRNA based pyrosequencing, we found that oral shedding of KSHV altered oral microbiota signature in HIV+ patients which may contribute to virus-associated malignancies development.