The human body is colonized by abundant and diverse microorganisms, collectively known as the microbiome. The oral cavity has more than 700 species of bacteria and consists of unique microbiome niches on mucosal surfaces, on tooth hard tissue, and in saliva. The homeostatic balance between the oral microbiota and the immune system plays an indispensable role in maintaining the well-being and health status of the human host. Growing evidence has demonstrated that oral microbiota dysbiosis is actively involved in regulating the initiation and progression of an array of autoimmune diseases.Oral microbiota dysbiosis is driven by multiple factors, such as host genetic factors, dietary habits, stress, smoking, administration of antibiotics, tissue injury and infection. The dysregulation in the oral microbiome plays a crucial role in triggering and promoting autoimmune diseases via several mechanisms, including microbial translocation, molecular mimicry, autoantigen overproduction, and amplification of autoimmune responses by cytokines. Good oral hygiene behaviors, low carbohydrate diets, healthy lifestyles, usage of prebiotics, probiotics or synbiotics, oral microbiota transplantation and nanomedicine-based therapeutics are promising avenues for maintaining a balanced oral microbiome and treating oral microbiota-mediated autoimmune diseases. Thus, a comprehensive understanding of the relationship between oral microbiota dysbiosis and autoimmune diseases is critical for providing novel insights into the development of oral microbiota-based therapeutic approaches for combating these refractory diseases.

Background: Gingivitis is the most prevalent form of periodontal disease in children and adolescents, being strongly associated to some socioeconomic factors and oral health behaviours. This study aimed to assess the prevalence of gingivitis and its association with socio-demographic factors and oral health-related behaviours in children aged 12–15 years in Guangdong, Southern China. Methods: A total of 7680 children were sampled using an equal-sized, stratified, multistage, random sampling method and clinically examined between December 2015 and April 2016. A questionnaire on socio-demographic factors and oral health-related behaviours related to gingivitis was completed by each of the selected children. Gingival bleeding was recorded using the Community Periodontal Index probe, and children with a gingival bleeding positive score ≥ 10% were defined as having gingivitis. A multivariate logistic regression analysis was performed to assess the association between socio-demographic factors and gingivitis. All statistical tests were performed at a two-sided significance level of 0.05. Results: The weighted prevalence of gingivitis among 12–15-year-old children was 29.6%, with 22.6% having localised gingivitis and 7.0% having generalised gingivitis. Age differences were observed in the prevalence of gingivitis, whereas urban-rural differences were not. According to the multivariate logistic regression analysis results, factors such as increasing age, being the only child, lack of regular annual dental check-up, and heavy dental calculus were significantly associated with higher prevalence of gingivitis. In addition, the association of gingivitis with these factors was inconsistent among the urban and rural areas. Conclusions: Dental calculus and oral health behaviour were found to be important factors for maintaining the gingival health of children aged 12–15 years in Guangdong. Maintaining gingival health in children requires promoting positive oral health behaviours and regular dental prophylaxis.

Background: Dental caries of deciduous teeth (Early Childhood Caries, ECC) has become a crucial oral health problem over the decades in China. The aim of this study was to examine the prevalence and severity of ECC among preschool children from Guangdong Province, Southern China. In addition, to assess the association of ECC with reported oral health-related behaviors. Methods: A cross-sectional survey of 2592 participants was carried out in Guangdong Province by means of an equal-sized, stratified, multistage random sampling method during December 2015 and April 2016. The participants were divided into three groups according to their ages (3-, 4-, and 5-year-olds). Half of the participants were derived from urban areas, while the other from rural areas. According to the standard for clinical dentition examination of the WHO 2013 criteria, the presence of ECC was determined by the dmft (decayed-missing-filled tooth) index using a CPI (Community Periodontal Index) probe. A questionnaire about caries-related factors was completed by each of the participants’ parents or grandparents through a face-to-face and one-on-one interview. Then, t-test, Chi² tests, One-Way ANOVA served for statistical analysis, and logistic regression analysis as well as covariance analysis were executed to identify potential associated factors for ECC. Results: The prevalence (% dmft > 0) of ECC was 68.3 (95% CI: 66.5–70.1), the mean dmft was 4.36 (95% CI: 4.17–4.55), and the filled rate was 1.2%. In multivariable modeling, associated factors for both prevalence and mean dmft were older age, rural areas, consumption of sweets before sleep, dental visit history, low household income, and low parental education level. Initiating toothbrushing after 3 years of age and being exclusively/ predominantly breastfed indicated only the prevalence; being female and frequently consuming sweetened milk/powdered milk indicated only the mean dmft. Conclusions: Preschool children in Guangdong Province, especially children from rural areas, experienced a significant amount of ECC. Associated factors for ECC included demographics, oral health measures, dietary factors, and socioeconomic factors. More attention should be given to prevention of ECC from early life. The construction of social support for oral health should be strengthened. Oral health education and promotion, especially of rural areas, should be intensified to reduce the inequality between urban and rural areas.

The oral microbiome is one of the most complex microbial communities in the human body and is closely related to oral and systemic health. Dental plaque biofilms are the primary etiologic factor of periodontitis, which is a common chronic oral infectious disease. The interdependencies that exist among the resident microbiota constituents in dental biofilms and the interaction between pathogenic microorganisms and the host lead to the occurrence and progression of periodontitis. Therefore, accurately and comprehensively detecting periodontal organisms and dissecting their corresponding functional activity characteristics are crucial for revealing periodontitis pathogenesis. With the development of metagenomics and metatranscriptomics, the composition and structure of microbial communities as well as the overall functional characteristics of the flora can be fully profiled and revealed. In this review, we will critically examine the currently available metagenomic and metatranscriptomic evidence to bridge the gap between microbial dysbiosis and periodontitis and related systemic diseases.

This research aimed to investigate the anti-tumor effects and underlying genetic mechanisms of herbal medicine Triphala (TRP) in oral squamous cell carcinoma (OSCC). The target genes of Triphala (TRP) in oral squamous cell carcinoma (OSCC) were identified, and subsequent functional enrichment analysis was conducted to determine the enriched signaling pathways. Based on these genes, a protein-protein interaction network was constructed to identify the top 10 genes with the highest degree. Genes deregulated in OSCC tumor samples were identified to be hub genes among the top 10 genes. In vitro experiments were performed to investigate the influence of TRP extracts on the cell metabolic activity, migration, invasion, apoptosis, and proliferation of two OSCC cell lines (CAL-27 and SCC-9). The functional rescue assay was conducted to investigate the effect of applying the inhibitor and activator of an enriched pathway on the phenotypes of cancer cells. In addition, the zebrafish xenograft tumor model was established to investigate the influence of TRP extracts on tumor growth and metastasis in vivo. The target genes of TRP in OSCC were prominently enriched in the PI3K-Akt signaling pathway, with the identification of five hub genes (JUN, EGFR, ESR1, RELA, and AKT1). TRP extracts significantly inhibited cell metabolic activity, migration, invasion, and proliferation and promoted cell apoptosis in OSCC cells. Notably, the application of TRP extracts exhibited the capacity to downregulate mRNA and phosphorylated protein levels of AKT1 and ESR1, while concomitantly inducing upregulation of mRNA and phosphorylated protein levels in the remaining three hub genes (EGFR, JUN, and RELA). The functional rescue assay demonstrated that the co-administration of TRP and the PI3K activator 740Y-P effectively reversed the impact of TRP on the phenotypes of OSCC cells. Conversely, the combination of TRP and the PI3K inhibitor LY294002 further enhanced the effect of TRP on the phenotypes of OSCC cells. Remarkably, treatment with TRP in zebrafish xenograft models demonstrated a significant reduction in both tumor growth and metastatic spread. Triphala exerted significant inhibitory effects on cell metabolic activity, migration, invasion, and proliferation in OSCC cell lines, accompanied by the induction of apoptosis, which was mediated through the inactivation of the PI3K/Akt pathway.