Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Department of Periodontology, Dental Clinic, Faculty of Medicine, Sigmund Freud University Vienna, Vienna, Austria.
Clin Exp Dent Res. 2024 Dec;10(6):e70016. doi: 10.1002/cre2.70016.
Fusobacterium can contribute to oral diseases, but also pose as a systemic risk factor. This genus, and especially F. nucleatum, can be found in colorectal cancer (CRC) tissue and is involved in multiple aspects of this type of cancer. Previous studies indicated a possible oral origin of these bacteria; however, stronger evidence is needed to reach a definitive conclusion. This pilot study aimed to establish a method to successfully compare, at the strain level, fusobacteria from the oral cavity and CRC resection material for future cohort studies of CRC patients.
In a first cohort of eight periodontitis patients, gingival crevicular fluid and saliva were collected. Fusobacterium was isolated on two different media. In a second cohort, saliva and CRC resection material were collected from ten CRC patients. These samples were used for screening of Fusobacterium with culturing, 16S rRNA gene profiling and a PCR-based approach.
In the first cohort, different Fusobacterium species were identified in GCF and saliva samples. However, as the total yield of Fusobacterium seemed slightly higher in saliva samples, it was therefore preferred for subsequent sample collection. Thus, in the second cohort, patient-matched saliva and CRC resection material were screened for Fusobacterium and this showed that nine patients were culture-positive in the saliva samples; however, no Fusobacterium could be isolated from the resection material. On the other hand, 16S rRNA gene profiling of the resection material indicated that eight CRC patients were positive for Fusobacterium. All eight of these patients carried Fusobacterium in their saliva, indicated by both marker gene PCR and culture-based screening.
These pilot results are compatible with data from previous studies, indicating a possible link between oral and CRC-associated Fusobacterium, and a more in-depth analysis of specific strains and their characteristics in a larger cohort is justified.
The protocol was registered at clinicaltrials.gov (NCT05945082).
梭杆菌可导致口腔疾病，也可成为系统性危险因素。该属，尤其是核梭杆菌，可存在于结直肠癌（CRC）组织中，并参与这种类型癌症的多个方面。先前的研究表明这些细菌可能具有口腔起源；然而，需要更强的证据来得出明确的结论。这项初步研究旨在建立一种方法，以便成功地比较口腔和 CRC 切除标本中的梭杆菌菌株，为 CRC 患者的未来队列研究提供依据。
在第一组 8 名牙周炎患者中，收集龈沟液和唾液。使用两种不同的培养基分离梭杆菌。在第二组中，从 10 名 CRC 患者中收集唾液和 CRC 切除标本。使用培养、16S rRNA 基因谱分析和基于 PCR 的方法筛选 Fusobacterium。
在第一组中，GCF 和唾液样本中鉴定出不同的梭杆菌种。然而，由于唾液样本中梭杆菌的总产量似乎略高，因此随后的样本采集更倾向于使用唾液。因此，在第二组中，对患者匹配的唾液和 CRC 切除标本进行 Fusobacterium 筛选，结果显示 9 名患者的唾液样本培养阳性；然而，从切除标本中无法分离出梭杆菌。另一方面，切除标本的 16S rRNA 基因谱分析表明，8 名 CRC 患者 Fusobacterium 阳性。所有这 8 名患者的唾液中均携带 Fusobacterium，这一点通过标记基因 PCR 和基于培养的筛选均得到证实。
这些初步结果与先前研究的数据相吻合，表明口腔和 CRC 相关 Fusobacterium 之间可能存在关联，有理由对更大的队列中特定菌株及其特征进行更深入的分析。
该方案在 clinicaltrials.gov 上注册（NCT05945082）。
