The microbial composition of a specific oral niche could be influenced by initial bacterial adherence, nutrient and physiological property of the local surface. To investigate the influence of nutrient and surface properties on microbial composition, saliva-derived biofilms were grown in agar on three substrata: Reconstructed Human Gingiva (RHG), a hydroxyapatite (HAP) surface, and a titanium (TI) surface. Agar was mixed with either Brain Heart Infusion (BHI) or Thompson (TP) medium. After 1, 3, or 5 days, biofilm viability (by colony forming units) and microbiome profiles (by 16 S rDNA amplicon sequencing) were determined. On RHG, biofilm viability and composition were similar between BHI and TP. However, on the abiotic substrata, biofilm properties greatly depended on the type of medium and substratum. In BHI, the viability of HAP-biofilm first decreased and then increased, whereas that of TI-biofilm decreased in time until a 6-log reduction. In TP, either no or a 2-log reduction in viability was observed for HAP- or TI-biofilms respectively. Furthermore, different bacterial genera (or higher level) were differentially abundant in the biofilms on 3 substrata: Haemophilus and Porphyromonas for RHG; Bacilli for HAP and Prevotella for TI. In conclusion, RHG, the biotic substratum, is able to support a highly viable and diverse microbiome. In contrast, the viability and diversity of the biofilms on the abiotic substrata were influenced by the substrata type, pH of the environment and the richness of the growth media. These results suggest that the host (oral mucosa) plays a vital role in the oral ecology.

特定口腔生态位的微生物组成可能受到局部表面的初始细菌粘附、营养和生理特性的影响。为了研究营养和表面特性对微生物组成的影响，唾液衍生的生物膜在琼脂中生长在三个基质上：重建的人牙龈 (RHG)、羟基磷灰石 (HAP) 表面和钛 (TI) 表面。琼脂与脑心浸液 (BHI) 或 Thompson (TP) 培养基混合。1、3 或 5 天后，测定生物膜活力（通过菌落形成单位）和微生物组谱（通过 16 S rDNA 扩增子测序）。在 RHG 上，BHI 和 TP 之间的生物膜活力和组成相似。然而，在非生物基质上，生物膜特性很大程度上取决于培养基和基质的类型。在 BHI 中，HAP-生物膜的生存力先下降后增加，而 TI-生物膜的生存力随时间下降，直到下降 6-log。在 TP 中，分别观察到 HAP 或 TI 生物膜的活力没有降低或降低 2 个对数。此外，不同细菌属（或更高水平）在 3 个基质上的生物膜中含量不同：RHG 的嗜血杆菌和卟啉单胞菌；用于 HAP 的杆菌和用于 TI 的Prevotella。总之，生物基质 RHG 能够支持高度可行和多样化的微生物组。相比之下，非生物基质上生物膜的活力和多样性受到基质类型、环境 pH 值和生长培养基丰富度的影响。这些结果表明宿主（口腔黏膜）在口腔生态学中起着至关重要的作用。