肠道菌群通过微生物和代谢产物在结直肠癌（CRC）发病机制中起着重要作用，而口腔病原体是CRC相关微生物的主要成分。多项研究已经确定了结直肠癌前体病变检测的肠道和粪便微生物组标志物。然而，很少有研究使用唾液样本预测结直肠息肉。因此，为了寻找新的非侵入性结直肠息肉生物标志物，我们对结直肠息肉患者和健康对照组的粪便和唾液微生物组进行了差异分析。 在这个病例对照研究中，我们在2021年5月至2022年11月之间收集了33名结直肠息肉（CP）患者和22名健康对照组（HC）的唾液和粪便样本。所有样本都使用全长16S rRNA测序，并与核苷酸序列数据库进行了比较。通过α和β多样性、线性判别分析效应大小（LEfSe）和随机森林模型分析，建立了结直肠息肉的唾液和粪便微生物组特征。此外，还通过受试者工作特征曲线（ROC）评估了微生物组在鉴别结直肠息肉中的可能性。 与HC组相比，CP组的唾液微生物多样性增加而粪便微生物多样性减少（p < 0.05），但微生物组丰富度差异不显著（p > 0.05）。主坐标分析显示CP组和HC组的唾液和粪便微生物组β-多样性存在显著差异。此外，LEfSe分析在物种水平上确定了Porphyromonas gingivalis、Fusobacterium nucleatum、Leptotrichia wadei、Prevotella intermedia和Megasphaera micronuciformis是唾液微生物组的主要贡献者，而Ruminococcus gnavus、Bacteroides ovatus、Parabacteroides distasonis、Citrobacter freundii和Clostridium symbiosum是结直肠息肉患者粪便微生物组的主要贡献者。唾液和粪便的细菌标志物的ROC曲线下面积分别为0.8167和0.8051，表明了其在区分结直肠息肉患者和对照组方面的诊断标记潜力，并且当唾液和粪便标志物组合时，ROC曲线下面积增加至0.8217。 与健康对照组相比，结直肠息肉患者的唾液和粪便微生物组成分和多样性明显不同，有害细菌的丰度增加，有益细菌的丰度减少。基于唾液和粪便微生物组的潜在生物标志物可能为结直肠息肉的检测提供了一个有前景的非侵入性工具。 版权 © 2023 Zhang, Feng, Li, Lv, Li, Hu, Fu and Song.

Gut microbiota plays an important role in colorectal cancer (CRC) pathogenesis through microbes and their metabolites, while oral pathogens are the major components of CRC-associated microbes. Multiple studies have identified gut and fecal microbiome-derived biomarkers for precursors lesions of CRC detection. However, few studies have used salivary samples to predict colorectal polyps. Therefore, in order to find new noninvasive colorectal polyp biomarkers, we searched into the differences in fecal and salivary microbiota between patients with colorectal polyps and healthy controls.In this case-control study, we collected salivary and fecal samples from 33 patients with colorectal polyps (CP) and 22 healthy controls (HC) between May 2021 and November 2022. All samples were sequenced using full-length 16S rRNA sequencing and compared with the Nucleotide Sequence Database. The salivary and fecal microbiota signature of colorectal polyps was established by alpha and beta diversity, Linear discriminant analysis Effect Size (LEfSe) and random forest model analysis. In addition, the possibility of microbiota in identifying colorectal polyps was assessed by Receiver Operating Characteristic Curve (ROC).In comparison to the HC group, the CP group's microbial diversity increased in saliva and decreased in feces (p < 0.05), but there was no significantly difference in microbiota richness (p > 0.05). The principal coordinate analysis revealed significant differences in β-diversity of salivary and fecal microbiota between the CP and HC groups. Moreover, LEfSe analysis at the species level identified Porphyromonas gingivalis, Fusobacterium nucleatum, Leptotrichia wadei, Prevotella intermedia, and Megasphaera micronuciformis as the major contributors to the salivary microbiota, and Ruminococcus gnavus, Bacteroides ovatus, Parabacteroides distasonis, Citrobacter freundii, and Clostridium symbiosum to the fecal microbiota of patients with polyps. Salivary and fecal bacterial biomarkers showed Area Under ROC Curve of 0.8167 and 0.8051, respectively, which determined the potential of diagnostic markers in distinguishing patients with colorectal polyps from controls, and it increased to 0.8217 when salivary and fecal biomarkers were combined.The composition and diversity of the salivary and fecal microbiota were significantly different in colorectal polyp patients compared to healthy controls, with an increased abundance of harmful bacteria and a decreased abundance of beneficial bacteria. A promising non-invasive tool for the detection of colorectal polyps can be provided by potential biomarkers based on the microbiota of the saliva and feces.Copyright © 2023 Zhang, Feng, Li, Lv, Li, Hu, Fu and Song.