Oral diseases (e.g., dental caries, periodontitis) are developed when the healthy oral microbiome is imbalanced allowing the increase of pathobiont strains. Common practice to prevent or treat such diseases is the use of antiseptics, like chlorhexidine. However, the impact of these antiseptics on the composition and metabolic activity of the oral microbiome is poorly addressed. Using two types of oral biofilms—a 14-species community (more controllable) and human tongue microbiota (more representative)—the impact of short-term chlorhexidine exposure was explored in-depth. In both models, oral biofilms treated with chlorhexidine exhibited a pattern of inactivation (>3 log units) and fast regrowth to the initial bacterial concentrations. Moreover, the chlorhexidine treatment induced profound shifts in microbiota composition and metabolic activity. In some cases, disease associated traits were increased (such as higher abundance of pathobiont strains or shift in high lactate production). Our results highlight the need for alternative treatments that selectively target the disease-associated bacteria in the biofilm without targeting the commensal microorganisms.

当健康的口腔微生物组失衡导致病原菌菌株增加时，就会发生口腔疾病（例如龋齿，牙周炎）。预防或治疗此类疾病的常用方法是使用消毒剂，如洗必泰。但是，这些防腐剂对口腔微生物组的组成和代谢活性的影响很少得到解决。使用两种类型的口腔生物膜-14种群落（更易于控制）和人舌微生物群（更具代表性）-深入研究了短期洗必泰暴露的影响。在这两种模型中，用洗必泰处理的口腔生物膜均表现出失活（> 3 log单位）的模式，并快速再生至初始细菌浓度。此外，氯己定治疗引起微生物群组成和代谢活性的深刻变化。在某些情况下，与疾病相关的特征会增加（例如，更高的致病菌菌株含量或高乳酸产量的变化）。我们的结果凸显了对选择性治疗生物膜中疾病相关细菌而不靶向共生微生物的替代治疗方法的需求。