School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.
Department of Renal and Pancreatic Transplantation, Manchester Academic Health Science Centre, Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom.
Microbiol Spectr. 2024 Nov 5;12(11):e0059824. doi: 10.1128/spectrum.00598-24. Epub 2024 Oct 9.
The oral microbiome is influenced by environmental factors in chronic kidney disease and following kidney transplantation affecting microbial composition, which may have implications for health and recovery. A major driver of oral microbiome perturbation is the accumulation of urea in saliva. We have modelled increased salivary urea concentrations associated with CKD and subsequent reductions that may occur post-transplantation. Oral microbiota were established in constant-depth film fermenters by inoculation with saliva. Duplicate validation runs were maintained with artificial saliva with baseline urea concentrations (0.205 mg/mL) for 21 days. Triplicate treatment runs were then done with baseline urea for 10 days (healthy phase) before urea was increased for 10 days to reflect CKD concentrations (0.92 mg/mL) (CKD phase). This was followed by reversion to baseline urea concentrations (post-transplant phase). Biofilms in primary validation runs reached dynamic stability within 5 days according to viable counting. DNA sequence data indicated minimal taxonomic variation over time and between low and high urea treatments despite background noise indicating changes in bacteria belonging to the family Gemellaceae and the genera TG5 and . Significant differences in alpha and beta diversity occurred between low and high urea states but not following reversion to a low urea environment. Increased abundance of the TG5 was detected in late model phases, despite apparent count stability, and independent of changes in urea concentrations.
This study investigates dynamic changes in the oral microbiome associated with changes in salivary urea concentration, an important factor in chronic kidney disease (CKD). The system modeled increased urea concentrations and subsequent reductions post-transplantation. The study provides insight into the oral microbial shifts during different simulated clinical phases. Understanding these dynamics is crucial for advancing our comprehension of CKD-associated oral microbiome variations and their potential impact on patient well-being and recovery.
口腔微生物组受慢性肾脏病和肾移植后环境因素的影响，影响微生物组成，这可能对健康和恢复有影响。口腔微生物组扰动的一个主要驱动因素是唾液中尿素的积累。我们模拟了与 CKD 相关的唾液中尿素浓度的增加，以及随后移植后可能发生的降低。通过用唾液接种，在恒深膜发酵器中建立口腔微生物群。用基线尿素浓度（0.205mg/ml）的人工唾液维持重复验证运行 21 天。然后用基线尿素进行 3 次处理运行 10 天（健康阶段），然后在 10 天内将尿素增加到反映 CKD 浓度（0.92mg/ml）（CKD 阶段）。然后再恢复到基线尿素浓度（移植后阶段）。根据活菌计数，主要验证运行中的生物膜在 5 天内达到动态稳定。DNA 序列数据表明，尽管背景噪音表明属于 Gemellaceae 科和 TG5 和 属的细菌发生了变化，但随着时间的推移和低尿素与高尿素处理之间的分类变化很小。低尿素和高尿素状态之间的 alpha 和 beta 多样性存在显著差异，但在恢复到低尿素环境后则没有差异。尽管计数稳定，但在模型后期仍检测到 TG5 的丰度增加，且与尿素浓度的变化无关。
