Acylhomoserine lactones (AHLs), the quorum-sensing (QS) signals produced by a range of Gram-negative bacteria, are involved in biofilm formation in many pathogenic and environmental bacteria. Nevertheless, the current paradigm excludes a role of AHLs in dental plaque formation, while other QS signals, such as AI-2 and autoinducer peptides, have been demonstrated to play an important role in biofilm formation and virulence-related gene expression in oral pathogens. In the present work, we have explored the effect of externally added AHLs on in vitro oral biofilm models for commensal, cariogenic, and periodontal dental plaque. While little effect on bacterial growth was observed, some AHLs specifically affected the lactic acid production and protease activity of the biofilms. Most importantly, the analysis of bacterial diversity in the biofilms showed that the addition of C₆-homoserine lactone (C₆-HSL) results in a shift toward a periodontal bacterial composition profile by increasing the relative presence of the orange-complex bacteria Peptostreptococcus and Prevotella. These results point to a relevant role of AHL-mediated QS in dental plaque formation and might be involved in the development of dysbiosis, the mechanism of which should be further investigated. This finding potentially opens new opportunities for the prevention or treatment of the periodontal disease.

IMPORTANCE Dental plaque is omnipresent in healthy oral cavities and part of our commensal microbial colonization. At the same time, dental plaque is the cause of the most common human diseases, caries and gum disease. Dental plaque consists of billions of microbes attached to the surface of your teeth. Communication among these microbes is pivotal for development of these complex communities yet poorly studied in dental plaque. In the present study, we show that a specific communication molecule induces changes within the community related to the development of gum disease. This finding suggests that interfering with microbial communication may represent an interesting novel strategy to prevent gum disease that should be further investigated.

酰基高丝氨酸内酯（AHLs）是由多种革兰氏阴性细菌产生的群体感应（QS）信号，在许多致病性和环境细菌中都参与生物膜的形成。然而，当前的范例排除了AHL在牙菌斑形成中的作用，而其他QS信号（如AI-2和自诱导肽）已被证明在口腔病原体的生物膜形成和与毒力相关的基因表达中起重要作用。在目前的工作中，我们探索了外部添加的AHL对体外的影响口腔生物膜模型，用于共生，龋齿和牙周牙菌斑。虽然观察到对细菌生长的影响很小，但是一些AHL特异性地影响了生物膜的乳酸产生和蛋白酶活性。最重要的是，对生物膜中细菌多样性的分析表明，添加C _6-高丝氨酸内酯（C ₆ -HSL）可通过增加橙色复合细菌Peptostreptococcus和Peptostreptococcus的相对存在而导致牙周细菌组成变化。小球藻。这些结果表明，AHL介导的QS在牙菌斑形成中具有相关作用，并且可能与营养不良的发生有关，应进一步研究其机制。这一发现潜在地为预防或治疗牙周疾病开辟了新的机会。

重要信息牙菌斑在健康的口腔中无处不在，并且是我们常见的微生物定植的一部分。同时，牙菌斑是人类最常见的疾病，龋齿和牙龈疾病的病因。牙菌斑由附着在牙齿表面的数十亿种微生物组成。这些微生物之间的交流对于这些复杂社区的发展至关重要，但在牙菌斑方面的研究却很少。在当前的研究中，我们表明特定的通信分子诱导与牙龈疾病的发展有关的社区内的变化。这一发现表明，干扰微生物的交流可能代表了一种有趣的预防牙龈疾病的新策略，应进一步研究。