IntroductionThe essence of enterotypes is to stratify the entire human gut microbiota, and dysregulation of gut microbiota is closely related to the development of colorectal adenoma. Enterotypes may therefore be a useful target for the prevention of colorectal adenoma. However, the relationship between gut microbiota and colorectal adenoma has not been fully elucidated. In this study, we aimed to analyze the differences in gut microbiome composition between adenoma and control populations.MethodsWe recruited 31 patients with colorectal adenoma and 71 non-adenoma controls. Patient demographics, risk factors, fecal samples from each subject were collected and metagenomic sequencing was performed. LEfSe analysis was used to reveal differences in intestinal microbiome composition. Multiple logistic regression analysis was used to determine the association between enterotypes and colorectal adenoma.ResultsThe results showed that Prevotella enterotype (enterotype 4) is only present in adenoma group. Logistic regression analysis showed that Prevotella enterotype was an independent risk factor for colorectal adenoma.DiscussionThe Prevotella enterotype may increase the occurrence of colorectal adenoma through inflammatory association and interference with glucose and lipid metabolism in human body. In conclusion, the differences we observed between different enterotypes add a new potential factor to the development of colorectal adenoma.

Background For colorectal cancer, preoperative (neoadjuvant) chemotherapy is more effective than postoperative chemotherapy because it not only eradicates micrometastases more effectively but also reduces the risk of incomplete intraoperative resection and tumor cell shedding. For the treatment of acute left-sided malignant colorectal obstruction, colorectal stents as well as stoma are being used to relieve the obstructive colorectal cancer, and as a bridge to surgery, allowing easy mobilization and resection of the colon. Neoadjuvant chemotherapy combined with self-expandable metal stents (SEMS) or neoadjuvant chemotherapy combined with decompressing stoma (DS) can be used as a bridge to elective surgery (BTS) as an alternative to emergency surgery in patients with acute left-sided malignant colorectal obstruction, but its benefit is uncertain. The purpose of this study was to evaluate the safety and feasibility of neoadjuvant chemotherapy as a bridge to surgery in the treatment of acute left-sided malignant colorectal obstruction. Methods Data from patients who were admitted with acute left-sided malignant colorectal obstruction between January 2012 and December 2020 were retrospectively reviewed, and patients with gastrointestinal perforation or peritonitis were excluded. We performed one-to-two propensity score matching to compare the stoma requirement, postoperative complications, and other short-term oncological outcomes between the neoadjuvant chemotherapy group and surgery group. Results There were no differences in intraoperative blood loss, operative time, one-year postoperative mortality, and postoperative tumor markers between the two groups. The 1-year recurrence-free survival (RFS) rates of neoadjuvant chemotherapy group and surgery group were 96.8 and 91.3% (p = 0.562). The neoadjuvant chemotherapy group was able to reduce stoma rate 1 year after surgery (p = 0.047). Besides, the neoadjuvant group significantly reduced postoperative bowel function time (p < 0.001), postoperative hospital stay (p < 0.001), total hospital stay (p = 0.002), postoperative complications (p = 0.017), reduction in need to stay in the intensive care unit (ICU) (p = 0.042). Conclusions Neoadjuvant chemotherapy as a bridge to elective surgery in patients with acute left-sided malignant colorectal obstruction is safe and has many advantages. Prospective multicenter studies with large samples are needed to further evaluate the feasibility of neoadjuvant chemotherapy.

Background: For colorectal cancer, preoperative (neoadjuvant) chemotherapy is more effective than postoperative chemotherapy because it eradicates micrometastases more effectively and reduces the risk of incomplete intraoperative resection and tumor cell shedding. For the treatment of acute left-sided malignant colorectal obstruction, colorectal stents as well as stoma are being used to relieve the obstructive colorectal cancer, and as a bridge to surgery, allowing easy mobilization and resection of the colon. Neoadjuvant chemotherapy combined with self-expanding metal stents or neoadjuvant chemotherapy combined with stoma can be used as a bridge to elective surgery as an alternative to emergency surgery in patients with acute left-sided malignant colorectal obstruction, but its benefit is uncertain. The purpose of this study was to evaluate the safety and feasibility of neoadjuvant chemotherapy as a bridge to surgery in the treatment of acute left-sided malignant colorectal obstruction.Methods: Data from patients who were admitted withacute left-sided malignant colorectal obstruction between January 2012 and December 2020 were retrospectively reviewed；Patients with peritonitis or bowel perforation were excluded. We performed one-to-two propensity score matching to compare the stoma requirement, postoperative complications, and other short-term oncological outcomes between the neoadjuvant chemotherapy group and surgery groups.Results: There were no differences in intraoperative blood loss, operative time,one-year postoperative mortality, and postoperative tumor markers between the two groups. The 1-year recurrence-free survival (RFS) rates of the surgery group and neoadjuvant chemotherapy group were 91.3% and 96.8%(p=0.562).The neoadjuvant chemotherapy group was able to reduce stoma rate one year after surgery(p =0.047).Besides,the neoadjuvant group significantly reduced postoperative bowel function time (p <0.001), postoperative hospital stay (p <0.001), total hospital stay (p = 0.002), postoperative complications (p = 0.017),and fewer access to intensive care unit treatment(p = 0.042).Conclusions: The use of neoadjuvant chemotherapy as a bridge to elective surgery in patients with acute left-sided malignant colorectal obstruction has many advantages, including faster recovery bowel function, enables early closure of the colostomy,reduce the incidence of postoperative complications, fewer transitions to intensive care unit or treatment,and reduce postoperative hospital stay. Neoadjuvant chemotherapy as a bridge to elective surgery for acute left-sided malignant colorectal obstruction is safe and feasible.

BackgroundThe optimal time interval between self-expanding metallic stent (SEMS) placement and surgery in patients with left-sided malignant colorectal obstruction (LMCO) remains controversial. Intestinal obstruction and SEMS placement would lead to intestinal edema, local tumor infiltration, and fibrosis, which may have a certain impact on elective surgery. Although prolong time interval would reduce relative complications, the risk of tumor progression must be taken into account. Therefore, our study proposes whether there is a difference in short-term postoperative complication outcomes between waiting for an interval of ≤4weeks compared with an extended interval for neoadjuvant chemotherapy followed by surgery.MethodsAll patients who underwent SEMS placement as BTS treatment for LMCO between January 2012 and December 2021 were retrospectively identified. The primary outcomes of this study were short-term clinical postoperative complications (Clavien-Dindo grading ≥II).ResultsOf the 148 patients, 70.27% of patients underwent surgery ≤4 weeks of SEMS placement (Group 1) while 29.73% of patients underwent surgery &gt;4 weeks of SEMS placement (Group 2). After SEMS placement, the patients in Group 2 received neoadjuvant chemotherapy and then elective surgery. Significant differences were observed between both groups (Group 2 vs Group 1) for postoperative complications (Clavien-Dindo grading ≥II, 2.3% vs 14.4%, p=0.040), postoperative bowel function time (p&lt;0.001), postoperative hospital stay (p=0.028) and total hospital stay (p=0.002).ConclusionsA bridging interval of &gt;4 weeks between SEMS placement and surgery for LMCO has better short-term clinical outcome.