Liang Weiren, Yang Yan, Wang Haiyong, Wang Haohao, Yu Xiongfei, Lu Yimin, Shen Shengrong, Teng Lisong
Department of Surgical Oncology.
Department of Laboratory, First Affiliated Hospital, School of Medicine.
Medicine (Baltimore). 2019 Aug;98(35):e16626. doi: 10.1097/MD.0000000000016626.
Gastric cancer (GC) is one of the common malignant tumors in China, with a high morbidity and mortality. With the development and application of high-throughput sequencing technologies and metagenomics, a great quantity of studies have shown that gastrointestinal microbiota is closely related to digestive system diseases. Although some studies have reported the effect of long-term follow-up after subtotal gastrectomy on intestinal flora changes in patients with GC. However, the features of gut microbiota and their shifts in patients with GC in perioperative period remain unclear.This study was designed to characterize fecal microbiota shifts of the patients with GC before and after the radical distal gastrectomy (RDG) during their hospital staying periods. Furthermore, fecal microbiota was also compared between the GC patients and healthy individuals.Patients who were diagnosed with advanced gastric adenocarcinoma at distal stomach were enrolled in the study. The bacterial burden within fecal samples was determined using quantitative polymerase chain reaction. To analyze the diversity and composition of gut microbiota from fecal DNA of 20 GC patients and 22 healthy controls, amplicons of the 16S rRNA gene from all subjects were pyrosequenced. To study gut microbiota shifts, the fecal microbiota from 6 GC patients before and after RDG was detected and subsequently analyzed. Short-chain fatty acids were also detected by chromatography spectrometer in these 6 GC patients.RDG had a moderate effect on bacterial richness and evenness, but had pronounced effects on the composition of postoperative gut microbiota compared with preoperative group. The relative abundances of genera Akkermansia, Esherichia/Shigella, Lactobacillus, and Dialister were significant changed in perioperative period. Remarkably, higher abundances of Escherichia/Shigella, Veillonella, and Clostridium XVIII and lower abundances of Bacteroides were observed in gut microbiota of overall GC patients compared to healthy controls.This study is the first study to characterize the altered gut microbiota within fecal samples from GC patients during perioperative period, and provide a new insights on such microbial perturbations as a potential effector of perioperative period phenotype. Further research must validate these discoveries and may evaluate targeted microbiota shifts to improve outcomes in GC patients.
胃癌（GC）是中国常见的恶性肿瘤之一，发病率和死亡率都很高。随着高通量测序技术和宏基因组学的发展与应用，大量研究表明胃肠道微生物群与消化系统疾病密切相关。虽然一些研究报道了胃大部切除术后长期随访对GC患者肠道菌群变化的影响。然而，GC患者围手术期肠道微生物群的特征及其变化仍不清楚。本研究旨在描述GC患者在接受根治性远端胃切除术（RDG）前后住院期间粪便微生物群的变化。此外，还比较了GC患者与健康个体之间的粪便微生物群。
本研究纳入了被诊断为远端胃高级别胃腺癌的患者。使用定量聚合酶链反应测定粪便样本中的细菌载量。为了分析20例GC患者和22例健康对照者粪便DNA中肠道微生物群的多样性和组成，对所有受试者16S rRNA基因的扩增子进行焦磷酸测序。为了研究肠道微生物群的变化，检测并随后分析了6例GC患者RDG前后的粪便微生物群。还通过色谱光谱仪检测了这6例GC患者的短链脂肪酸。
RDG对细菌丰富度和均匀度有中度影响，但与术前组相比，对术后肠道微生物群的组成有显著影响。围手术期阿克曼氏菌属、埃希氏菌属/志贺氏菌属、乳杆菌属和戴阿利斯特菌属的相对丰度有显著变化。值得注意的是，与健康对照相比，在总体GC患者的肠道微生物群中观察到埃希氏菌属/志贺氏菌属、韦荣氏球菌属和 XVIII 梭菌属的丰度较高，而拟杆菌属的丰度较低。
本研究是首次描述GC患者围手术期粪便样本中肠道微生物群变化的研究，并为这种微生物扰动作为围手术期表型的潜在效应物提供了新的见解。进一步的研究必须验证这些发现，并可能评估有针对性的微生物群变化以改善GC患者的预后。
