Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
College of Stomatology, Shanghai Jiao Tong University, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai, China.
Front Cell Infect Microbiol. 2023 Dec 6;13:1321855. doi: 10.3389/fcimb.2023.1321855. eCollection 2023.
Microbiota and their interaction with hosts have been of great interest in brain research in recent years. However, the role of oral microbiota in mental illness and the underlying mechanism of oral-brain communication remains elusive. Sleep bruxism (SB) is an oral parafunctional activity related to the nervous system and is considered a risk factor for harmful clinical consequences and severe systemic conditions. Exploring the connection between oral microbiota and sleep bruxism may deepen our understanding of the complex relationship between oral-brain axis and provide insights for treatment.
In this study, salivary samples were collected from 22 individuals with SB and 21 healthy controls, and metagenomics with metabolomics was performed. Nonparametric Wilcoxon test were applied for the statistical analysis between the two groups. Microbial dysbiosis and altered oral metabolites were found in the SB individuals.
The characteristic metabolite N-acetylglucosamine (GlcNAc) (VIP=8.4823, P<0.05) was correlated to a statistically lower Streptococcus mitis level in SB individuals. Salivary IFN-g level and IFN-g/IL-4 ratio were detected with significant changes in a chip assay. Amino acid metabolism pathways were upregulated, and the pathway with the largest number of differentially expressed genes is related to amino-tRNA charging pathway, while the most significantly enriched pathway is related to arginine biosynthesis. Neurotransmitter-associated pathways with glutamatergic and GABAergic synapses and cardiovascular system-related pathways were enriched in the SB group.
These results indicate a possible neuroimmune regulatory network of oral-brain communication in SB, which helps explain the mechanism of the oral microbiome with the host in sleep bruxers and provides a reference for early clinical and therapeutic intervention to improve the diagnosis and treatment of SB and similar diseases.
近年来，微生物群及其与宿主的相互作用在脑研究中引起了极大的关注。然而，口腔微生物群在精神疾病中的作用以及口腔-脑通讯的潜在机制仍不清楚。磨牙症（SB）是一种与神经系统相关的口腔功能障碍活动，被认为是有害临床后果和严重系统性疾病的风险因素。探索口腔微生物群与睡眠磨牙症之间的联系，可以加深我们对口腔-脑轴复杂关系的理解，并为治疗提供新的思路。
本研究从 22 名 SB 患者和 21 名健康对照者中采集唾液样本，进行宏基因组学和代谢组学分析。采用非参数 Wilcoxon 检验比较两组间的差异。结果发现，SB 患者存在微生物失调和口腔代谢物改变。
特征代谢物 N-乙酰葡萄糖胺（GlcNAc）（VIP=8.4823，P<0.05）与 SB 患者中链球菌显著降低相关。芯片检测到唾液 IFN-γ 水平和 IFN-γ/IL-4 比值发生显著变化。氨基酸代谢途径上调，差异表达基因数量最多的途径与氨基-tRNA 充能途径有关，而最显著富集的途径与精氨酸生物合成有关。神经递质相关途径（谷氨酸能和 GABA 能突触）和心血管系统相关途径在 SB 组中富集。
这些结果表明，在 SB 中存在一种可能的口腔-脑通讯的神经免疫调节网络，有助于解释口腔微生物群与宿主在睡眠磨牙症中的作用机制，并为早期临床和治疗干预提供参考，以改善 SB 和类似疾病的诊断和治疗。
