Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
Division of Colorectal Surgery, Department of Surgery, National University Hospital, Singapore, Singapore.
Sci Rep. 2022 Jun 14;12(1):9829. doi: 10.1038/s41598-022-14203-z.
There is growing interest in the role of gut microbiome in colorectal cancer (CRC), ranging from screening to disease recurrence. Our study aims to identify microbial markers characteristic of CRC and to examine if changes in bacteriome persist after surgery. Forty-nine fecal samples from 25 non-cancer (NC) individuals and 12 CRC patients, before and 6-months after surgery, were collected for analysis by bacterial 16S rRNA gene sequencing. Bacterial richness and diversity were reduced, while pro-carcinogenic bacteria such as Bacteroides fragilis and Odoribacter splanchnicus were increased in CRC patients compared to NC group. These differences were no longer observed after surgery. Comparison between pre-op and post-op CRC showed increased abundance of probiotic bacteria after surgery. Concomitantly, bacteria associated with CRC progression were observed to have increased after surgery, implying persistent dysbiosis. In addition, functional pathway predictions based on the bacterial 16S rRNA gene data showed that various pathways were differentially enriched in CRC compared to NC. Microbiome signatures characteristic of CRC comprise altered bacterial composition. Elements of these dysbiotic signatures persists even after surgery, suggesting possible field-change in remnant non-diseased colon. Future studies should involve a larger sample size with microbiome data collected at multiple time points after surgery to examine if these dysbiotic patterns truly persist and also correlate with disease outcomes.
人们对肠道微生物组在结直肠癌（CRC）中的作用越来越感兴趣，从筛查到疾病复发。我们的研究旨在确定CRC 特征性的微生物标志物，并检查在手术后细菌组是否会发生变化。收集了 25 名非癌症（NC）个体和 12 名 CRC 患者的 49 份粪便样本，在手术前和手术后 6 个月进行细菌 16S rRNA 基因测序分析。与 NC 组相比，CRC 患者的细菌丰富度和多样性降低，而促癌细菌如梭状芽孢杆菌和内脏杆菌的丰度增加。这些差异在手术后不再观察到。在 CRC 患者的术前和术后比较中，术后益生菌细菌的丰度增加。同时，观察到与 CRC 进展相关的细菌在手术后增加，这意味着持续的肠道菌群失调。此外，基于细菌 16S rRNA 基因数据的功能途径预测表明，与 NC 相比，CRC 中存在各种途径的差异富集。CRC 特征性的微生物组特征包括细菌组成的改变。即使在手术后，这些肠道菌群失调特征的某些元素仍然存在，这表明残余非病变结肠可能存在潜在的变化。未来的研究应该包括更大的样本量，并在手术后多个时间点收集微生物组数据，以检查这些肠道菌群失调模式是否确实持续存在，并与疾病结果相关。
