The long term microbiota and metabolic status in patients with colorectal cancer after curative colon surgery

Whether there are subsequent changes of metabolic profiles and microbiota status after partial colectomy remains unknown. We evaluated and compared long-term effects of microbiota status and metabolic profiles in early colorectal cancer (CRC) patients after curative colectomy to the controls. In this cross-sectional study, we analyzed metabolic syndrome occurrence in 165 patients after curative partial colectomy with right hemicolectomy (RH) or low anterior resection (LAR) and 333 age-sex matched controls. Fecal samples from some of those with RH, LAR, and controls were analyzed by next-generation sequencing method. The occurrences of metabolic syndrome were significantly higher in patients after RH, but not LAR, when compared with the controls over the long term (> 5 years) follow-up (P = 0.020). Compared with control group, RH group showed lower bacterial diversity (P = 0.007), whereas LAR group showed significantly higher bacterial diversity at the genera level (P = 0.016). Compared with the control group, the principal component analysis revealed significant differences in bacterial genera abundance after RH and LAR (P < 0.001). Furthermore, the Firmicutes to Bacteroidetes ratio was significantly lower in the RH group than the control group (22.0% versus 49.4%, P < 0.05). In conclusion, early CRC patients after RH but not LAR were associated with a higher occurrence of metabolic syndrome than the controls during long-term follow-up. In parallel with metabolic change, patients with RH showed dysbiosis with a tendency to decreased richness and a significant decrease in the diversity of gut microbiota.

部分结肠切除术后代谢谱与微生物群状态是否会发生后续变化，目前尚不明确。本研究针对接受根治性结肠切除术的早期结直肠癌（colorectal cancer, CRC）患者与对照组，评估并比较了二者术后微生物群状态与代谢谱的长期影响。本项横断面研究中，我们纳入165名接受根治性部分结肠切除术（术式为右半结肠切除术（right hemicolectomy, RH）或低位前切除术（low anterior resection, LAR））的患者，以及333名年龄与性别匹配的对照个体，分析了代谢综合征的发生情况。我们采用下一代测序（next-generation sequencing）技术，对部分RH组、LAR组患者及对照组个体的粪便样本进行了检测分析。长期随访（>5年）结果显示，与对照组相比，RH组患者的代谢综合征发生率显著升高（P=0.020），而LAR组则无此差异。与对照组相比，RH组的细菌多样性更低（P=0.007），而LAR组在属水平上的细菌多样性则显著升高（P=0.016）。主成分分析（principal component analysis）结果显示，与对照组相比，RH组与LAR组患者的细菌属丰度均存在显著差异（P<0.001）。此外，RH组的厚壁菌门（Firmicutes）与拟杆菌门（Bacteroidetes）比值显著低于对照组（22.0% vs 49.4%，P<0.05）。综上，长期随访期间，接受RH的早期CRC患者较对照组代谢综合征发生率更高，而接受LAR的患者则无此差异。与代谢改变同步的是，RH组患者出现了肠道菌群失调，表现为菌群丰富度呈下降趋势，且细菌多样性显著降低。