Colorectal cancer (CRC) and periodontitis have recently been related due to the higher incidence of CRC in periodontal patients and the involvement of periodontal pathogens in carcinogenesis, suggesting that leakage from the oral cavity to the gut occurs. However, the magnitude of this pass-through in healthy individuals is controversial, and the effect that periodontitis could play in it is understudied. To evaluate the rate of bacterial leakage from the oral cavity to the gut, we analyzed the microbial composition of saliva, subgingival plaque, and fecal samples in healthy individuals without gastrointestinal disorders, including 20 periodontitis patients and 20 oral healthy controls, using PacBio full-length 16S rRNA gene sequencing. As expected, we observed a higher abundance of periodontal pathogens in the subgingival plaque and saliva of periodontal patients. In contrast, no significant differences were found between the fecal samples of both groups, implying that gut samples from periodontal patients were not enriched in periodontal pathogens. Fusobacterium nucleatum, a biomarker of CRC, was not found in the fecal samples of any participant. Our study does show a small leakage of some oral bacteria (mainly streptococci) to the gut, regardless of periodontal health status. Future studies should test whether other host factors and/or the preexistence of a gut disorder must be present in addition to periodontitis to promote the colonization of the gut by oral pathogens. The absence of periodontal pathogens in feces supports the idea that these bacteria could be used as biomarkers of intestinal disorders, including CRC.

中文翻译：

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牙周炎对口腔细菌渗漏至肠道的影响


最近，结直肠癌（CRC）和牙周炎相关，因为牙周患者结直肠癌的发病率较高，并且牙周病原体参与癌变，这表明发生了从口腔渗漏到肠道的情况。然而，这种传递在健康个体中的程度存在争议，并且牙周炎可能发挥的影响尚未得到充分研究。为了评估细菌从口腔渗漏到肠道的速度，我们使用 PacBio 全面分析了无胃肠道疾病的健康个体（包括 20 名牙周炎患者和 20 名口腔健康对照）的唾液、龈下菌斑和粪便样本的微生物组成。长度16S rRNA基因测序。正如预期的那样，我们观察到牙周患者龈下菌斑和唾液中牙周病原体的丰度较高。相比之下，两组粪便样本之间没有发现显着差异，这意味着牙周患者的肠道样本中牙周病原体并不富集。在任何参与者的粪便样本中均未发现具核梭杆菌（CRC 的生物标志物）。我们的研究确实表明，无论牙周健康状况如何，一些口腔细菌（主要是链球菌）都会少量渗漏到肠道。未来的研究应该测试除了牙周炎之外是否还必须存在其他宿主因素和/或先前存在的肠道疾病，以促进口腔病原体在肠道的定植。粪便中不存在牙周病原体，这支持了这样的观点：这些细菌可以用作肠道疾病（包括结直肠癌）的生物标志物。