Colorectal adenomatous polyps (CAPs) are considered precancerous lesions of colorectal cancer (CRC). The gut microbiota participates in the process of digestion and, in the process, produces metabolites, mainly short-chain fatty acids (SCFAs), secondary bile acids and conjugated linoleic acid (CLA). This study aimed to investigate the gut microbiota constituents and metabolites in the faeces of CAP patients to identify microbiota or metabolites that can be used as sensitive biological predictors and to provide a theoretical basis for the clinical treatment of CAPs. 16S rRNA sequence analysis was used to detect microbial changes in the faeces of CAP patients. qPCR analysis was used to evaluate the ability of the microbiota to produce metabolites, and the contents of metabolites in faeces were detected by ion chromatography and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Based on the detection of the gut microbiota, patients with CAPs had increased abundances of Bacteroides and Citrobacter, and the abundances of Weissella and Lactobacillus were decreased. We also explored gene expression, and the abundance of butyrate-producing bacterial genes was significantly increased in the faeces of CAP patients, but those of secondary bile acid-producing and CLA-producing bacterial genes showed no differences in faecal samples. The acetic acid and butyric acid contents were increased in the faeces of the CAP group, and the healthy control group had higher t10,c12-CLA contents. The gut microbiota analysis results, assessed in faeces, showed that Bacteroides and Citrobacter were positively correlated with CAPs, which indicated that changes in specific genera might be detrimental to intestinal health. In addition, t10,c12-CLA played an important role in protecting the intestine.

中文翻译：

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大肠腺瘤性息肉患者的细菌，丁酸和t10，c12-CLA变化

大肠腺瘤性息肉（CAPs）被认为是大肠癌癌前病变（CRC）。肠道菌群参与消化过程，并在此过程中产生代谢产物，主要是短链脂肪酸（SCFA），仲胆汁酸和共轭亚油酸（CLA）。这项研究旨在调查CAP患者粪便中的肠道微生物群组成和代谢产物，以鉴定可用作敏感生物预测因子的微生物群或代谢产物，并为CAP的临床治疗提供理论依据。16S rRNA序列分析用于检测CAP患者粪便中的微生物变化。使用qPCR分析来评估微生物群产生代谢产物的能力，采用离子色谱法和超高效液相色谱-串联质谱法（UPLC-MS / MS）检测粪便中代谢物的含量。根据肠道菌群的检测，CAP患者的细菌和柠檬酸杆菌的丰度增加，魏氏菌和乳杆菌的丰度降低。我们还探讨了基因表达，CAP患者粪便中产生丁酸的细菌基因的丰度显着增加，但是次生胆汁酸和CLA产生细菌的基因在粪便样品中没有差异。CAP组的粪便中乙酸和丁酸含量增加，健康对照组的t10，c12-CLA含量较高。肠道菌群分析结果，以粪便评估，结果表明，拟杆菌和柠檬酸杆菌与CAPs呈正相关，这表明特定属的改变可能对肠道健康有害。此外，t10，c12-CLA在保护肠道中也起着重要作用。