Streptococcus mutans is recognized as the main cause of dental caries, and the formation of a plaque biofilm is required for caries development. This study aimed to determine the inhibitory effect of Lactobacillus plantarum FB-T9 on S. mutans biofilm formation in vitro and on the prevention and treatment of dental caries in rats. During in vitro experiments, FB-T9 exhibited good bacteriostatic ability in a plate competition assay. This strain also significantly reduced the biomass and viability of S. mutans biofilms and induced structural damage during the early (6 h), middle (12 h) and late (24 h) stages of biofilm formation. In a 70-day in vivo experiment, FB-T9 significantly reduced the levels of S. mutans on the dental surfaces of rats by more than 2 orders of magnitude of the levels in the dental caries model group (p < 0.05). Moreover, FB-T9 significantly reduced the caries scores (modified Keyes scoring method) in both the prevention and treatment groups (p < 0.05) and had great colonization potential in the oral cavity. These results indicate the potential usefulness of L. plantarum FB-T9 as a probiotic for the prevention and treatment of caries.

中文翻译：

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植物乳杆菌FB-T9对大鼠龋齿的抑制和预防作用。

变形链球菌被认为是龋齿的主要原因，并且龋齿发展需要形成斑块生物膜。这项研究旨在确定植物乳杆菌FB-T9对变形链球菌体外生物膜形成的抑制作用以及对大鼠龋齿的预防和治疗。在体外实验中，FB-T9在平板竞争试验中表现出良好的抑菌能力。该菌株还显着降低了变形链球菌生物膜的生物量和生存能力，并在生物膜形成的早期（6 h），中间（12 h）和晚期（24 h）阶段引起了结构破坏。在一个为期70天的体内实验中，FB-T9显着降低了大鼠龋齿中变形链球菌的水平，比龋齿模型组的水平降低了2个数量级以上（p <0.05）。此外，FB-T9在预防和治疗组中均显着降低了龋齿评分（改良的Keyes评分方法）（p <0.05），并且在口腔中具有很大的定殖潜力。这些结果表明植物乳杆菌FB-T9作为益生菌用于预防和治疗龋齿的潜在有用性。