The gut microbiota composition has no predictive value for the endotoxin-induced immune response or development of endotoxin tolerance in humans invivo.

BACKGROUND: It is largely unknown whether the gut microbiome regulates immune responses in humans. We determined relationships between the microbiota composition and immunological phenotypes in 108 healthy volunteers, using 16S sequencing, an ex vivo monocyte challenge model, and an in vivo challenge model of systemic inflammation induced by lipopolysaccharide (LPS). RESULTS: Significant associations were observed between the microbiota composition and ex vivo monocytic cytokine responses induced by several stimuli, most notably IL-10 production induced by Pam3Cys, Pseudomonas aeruginosa and Candida albicans, although the explained variance was rather low (0.3-4.8%). Furthermore, a number of pairwise correlations between Blautia, Bacteroides and Prevotella genera and cytokine production induced by these stimuli were identified. LPS administration induced a profound transient in vivo inflammatory response. A second LPS challenge one week after the first resulted in a severely blunted response, reflecting endotoxin tolerance. However, no significant relationships between microbiota composition and in vivo parameters of inflammation or tolerance were found (explained variance ranging from 0.4 to 1.5%, ns). CONCLUSIONS: The gut microbiota composition explains a limited degree of variance in ex vivo monocytic cytokine responses to several pathogenic stimuli, but no relationships with the LPS-induced in vivo immune response or tolerance was observed.

The association between anastomotic leakage and health-related quality of life after colorectal cancer surgery.

AIM: Colorectal anastomotic leakage (AL) is a serious complication. Studies on the impact of AL on health-related quality of life (HRQoL) are scarce. We aimed to investigate the association between AL and HRQoL in colorectal cancer patients up to 2 years after diagnosis, and to evaluate whether AL is associated with a clinically relevant decrease in HRQoL over time. METHODS: Patients diagnosed with Stage I-III colorectal cancer undergoing elective surgical resection with primary anastomosis between 2010 and 2017 were included. HRQoL was evaluated using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30, represented by the summary score, and analysed at diagnosis and at 6 months and 2 years post-diagnosis. Multivariable linear regression was performed to assess the association between AL and HRQoL, while multivariable logistic regression was used to investigate the association between AL and a clinically relevant HRQoL decrease (≥10 points) during follow-up compared to the time of diagnosis. RESULTS: In total, 1197 patients were included of whom 63 (5%) developed AL. AL was not associated with HRQoL at 6 months post-diagnosis nor at 2 years post-diagnosis. However, having AL was associated with an increased risk of a clinically relevant decrease in HRQoL at 6 months post-diagnosis (OR 3.65, 95% CI 1.62-8.21) but not at 2 years after diagnosis (OR 1.91, 95% CI 0.62-5.93). CONCLUSION: Although AL was not associated with HRQoL at 6 months or 2 years post-diagnosis, AL was a determinant of a clinically relevant decrease in HRQoL at 6 months after diagnosis. Future work should identify feasible and effective strategies to prevent declines in QoL in this patient population.

Long-Term Oncological Outcomes After Colorectal Anastomotic Leakage: A Retrospective Dutch Population-based Study.

OBJECTIVE: The aim was to evaluate the impact of anastomotic leak (AL) after colon cancer (CC) and rectal cancer (RC) surgery on 5-year relative survival, disease-free survival (DFS), and disease recurrence. BACKGROUND: AL after CC and RC resection is a severe postoperative complication with conflicting evidence whether it deteriorates long-term outcomes. METHODS: Patients with stage I to IV CC and RC who underwent resection with primary anastomosis were included from the Netherlands Cancer Registry (2008-2018). Relative survival, measured from day of resection, and multivariable relative excess risks (RERs) were analyzed. DFS and recurrence were evaluated in a subset with stage I to III patients operated in 2015. All analyses were performed with patients who survived 90 days postoperatively. RESULTS: A total of 65,299 CC and 22,855 RC patients were included. Five-year relative survival after CC resection with and without AL was 95% versus 100%, 89% versus 94%, 66% versus 76%, and 28% versus 25% for stage I to IV disease. AL was associated with a significantly higher RER for death in stage II and III CC patients. Stage-specific 5-year relative survival in RC patients with and without AL was 97% versus 101%, 90% versus 95%, 74% versus 83%, and 32% versus 41%. AL was associated with a significantly higher RER for death in stage III and IV RC patients. DFS was significantly lower in CC patients with AL, but disease recurrence was not associated with AL after colorectal cancer resection. CONCLUSION: AL has a stage-dependent negative impact on survival in both CC and RC, but no independent association with disease recurrence.

Mesenteric occlusive disease of the inferior mesenteric artery is associated with anastomotic leak after left-sided colon and rectal cancer surgery: a retrospective cohort study.

PURPOSE: Anastomotic leak (AL) is a serious complication following colorectal surgery. Atherosclerosis causes inadequate anastomotic perfusion and is suggested to be a risk factor for AL. The aim of this study was to investigate the association of mesenteric occlusive disease on preoperative computed tomography (CT) scan with AL after left-sided colon or rectal cancer surgery. METHODS: This was a retrospective, multicenter cohort study including 1273 patients that underwent left-sided or rectal cancer resection between 2009 and 2018 from three hospitals in the Netherlands. AL patients were 1:1 matched with non-leak patients and preoperative contrast-enhanced CT-scans were retrospectively analyzed for mesenteric atherosclerotic lesions. The main outcome measure was the presence of mesenteric occlusive disease on the preoperative CT-scan. RESULTS: Anastomotic leak developed in 6% of 1273 patients (N = 76). Low anterior resection and stage I-III disease were statistically significant associated with AL (p = 0.01, p = 0.04). No other statistically significant differences in patient characteristics between AL and non-leak patients were found. A clinically significant stenosis (≥ 70-100%) of the inferior mesenteric artery was statistically significant more frequent present in AL patients, compared to non-leak patients (p < 0.01). No statistically significant differences in the presence of mesenteric occlusive disease of the celiac artery and superior mesenteric artery between AL patients and non-leak patients were found. CONCLUSION: Mesenteric occlusive disease of the IMA on preoperative CT-scan is associated with AL after left-sided colon or rectal resection for cancer. Preoperative identification of high-risk patients with a preoperative CT-scan of the mesenteric vasculature might be useful to reduce the risk of AL.

Trends in risk factors of anastomotic leakage after colorectal cancer surgery (2011-2019): A Dutch population-based study.

AIM: Anastomotic leakage (AL) after colon cancer (CC) and rectal cancer (RC) surgery often requires reintervention. Prevalence and morbidity may change over time with evolutions in treatment strategies and changes in patient characteristics. This nationwide study aimed to evaluate changes in the incidence, risk factors and mortality from AL during the past nine years. METHODS: Data of CC and RC resections with primary anastomosis were extracted from the Dutch Colorectal Audit (2011-2019). AL was registered if requiring reintervention. Three consecutive cohorts were compared using logistic regression analysis. RESULTS: Incidence of AL after CC surgery decreased from 6.6% in 2011-2013 to 4.8% in 2017-2019 and increased from 8.6% to 11.9% after RC surgery. In 2011-2013, male sex, ASA ≥3, (y)pT3-4, neoadjuvant therapy, emergency surgery and multivisceral resection were identified as risk factors for AL after CC surgery. In 2017-2019, only male sex and ASA ≥3 were risk factors for AL. For RC patients, male sex and neoadjuvant therapy were a risk factor for AL in 2011-2013. In 2017-2019, transanal approach was also a risk factor for AL. Postoperative mortality rate after AL was 12% (CC) and 2% (RC) in 2017-2019, without significant changes over time. CONCLUSION: Contradictory trends in incidence and mortality for AL were observed among CC and RC surgery with changing risk factors over the past 9 years. High mortality after AL is only observed after CC surgery and remains unchanged. Continued efforts should be made to improve early detection and treatment of AL for these patients.

Association of Habitual Preoperative Dietary Fiber Intake With Complications After Colorectal Cancer Surgery.

IMPORTANCE: Postoperative complications are associated with increased morbidity and mortality among patients with colorectal cancer. As a modifiable factor associated with gut health, dietary fiber intake is of interest with regard to the risk of complications after surgery for colorectal cancer. OBJECTIVE: To examine the association between preoperative dietary fiber intake and risk of complications after surgery for colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS: This cohort study used data from the Colorectal Longitudinal, Observational Study on Nutritional and Lifestyle Factors (COLON) study, which recruited adult patients with colorectal cancer at any stage at diagnosis from 11 hospitals in the Netherlands between August 2010 and December 2017. The present study included patients with stage I to IV colorectal cancer who underwent elective abdominal surgery. Data were analyzed between December 2019 and September 2020. EXPOSURES: Habitual dietary fiber intake was assessed at diagnosis using a 204-item food frequency questionnaire. MAIN OUTCOMES AND MEASURES: Any complications, surgical complications, and anastomotic leakage occurring during the 30 days after surgery for colorectal cancer. The association between fiber intake and risk of postoperative complications was assessed using logistic regression analyses. Additional analyses stratified by sex, tumor location, and fiber source were performed. RESULTS: Among the 1399 patients included in the analysis, the median age at inclusion was 66 years (interquartile range, 61-72 years) and 896 (64%) were men. Any complications occurred in 397 patients (28%), and surgical complications occurred in 235 patients (17%). Of 1237 patients with an anastomosis, 67 (5%) experienced anastomotic leakage. Higher dietary fiber intake (per 10 g per day) was associated with a lower risk of any complications (odds ratio [OR], 0.75; 95% CI, 0.62-0.92) and surgical complications (OR, 0.76; 95% CI, 0.60-0.97), whereas no association with anastomotic leakage was found (OR, 0.97; 95% CI, 0.66-1.43). Among women, higher dietary intake was associated with any complications (OR, 0.64; 95% CI, 0.44-0.94), whereas there was no association among men (OR, 0.79; 95% CI, 0.63-1.01). Fiber intake from vegetables (per 1 g per day) was inversely associated with any (OR, 0.90; 95% CI, 0.83-0.99) and surgical (OR, 0.87; 95% CI, 0.78-0.97) complications. CONCLUSIONS AND RELEVANCE: In this cohort study, higher habitual dietary fiber intake before surgery was associated with a lower risk of postoperative complications among patients with colorectal cancer. The findings suggest that improving preoperative dietary fiber intake may be considered in future prehabilitation programs for patients undergoing surgery for colorectal cancer.

Postoperative administration of non-steroidal anti-inflammatory drugs in colorectal cancer surgery does not increase anastomotic leak rate; A systematic review and meta-analysis.

BACKGROUND: Evidence on the effect of non-steroidal anti-inflammatory drugs (NSAIDs) on anastomotic leak (AL) rate after colorectal surgery is conflicting. Effects of NSAIDs might depend on the underlying disease. This meta-analysis aimed to review the effect of NSAIDs on AL rate in a homogeneous colorectal cancer patient population. METHODS: A systematic literature search using MEDLINE and EMBASE database was performed for studies with AL as primary outcome comparing NSAID use in the early postoperative phase with no NSAID administration in colorectal cancer patients undergoing surgical resection. RESULTS: Nine studies including 10,868 patients met the inclusion criteria. The majority, 7689 patients (70.7%) underwent low anterior resection and 3050 patients (28.1%) underwent colonic resection. The pooled incidence of AL was 8.6% (95%CI 7.0-10.0). Overall AL rate after colorectal cancer surgery was not increased in patients using NSAIDs for postoperative analgesia compared to non-users (p = 0.34, RR 1.23; 95%CI 0.81-1.86). This effect remained non-significant after stratification for low anterior resections (p = 0.07). Stratification for colonic resections could not be performed because AL results for this subgroup were not reported separately. Neither non-selective NSAID use nor COX-2 selective NSAID use caused an increased AL rate (p = 0.19, p = 0.26). The results were robust throughout sensitivity analyses. CONCLUSION: Use of NSAIDs in cohorts with patients undergoing surgical resection for colorectal cancer does not increase overall AL rate. Since results were robust throughout several subgroup and sensitivity analyses, prescription of NSAIDs after colorectal cancer surgery seems safe.

Microbial Glucuronidase Inhibition Reduces Severity of Diclofenac-Induced Anastomotic Leak in Rats.

BACKGROUND: The non-steroidal anti-inflammatory drug diclofenac has been associated with intestinal anastomotic leakage, although the underlying pathophysiology is unclear. Previous data suggest that reactivation of biliary diclofenac metabolites by microbial ß-glucuronidases in the gut plays a role in harming the intestinal mucosa, and that microbiome-targeted glucuronidase inhibition prevents this damage. Here, the microbial glucuronidase inhibitor Inh1 was examined for its ability to reduce diclofenac-induced anastomotic leakage in rats. METHODS: Ninety male Wistar rats were allocated to five groups. In the two diclofenac groups, group DCF received diclofenac (3 mg/kg per day) and group DCF-Inh1 additionally received 800 mcg/kg per day of glucuronidase inhibitor Inh1 solution orally. In non-diclofenac groups, animals received either Inh1 (800 mcg/kg per day; group Inh1) solution, the vehicle (methylcellulose; group Veh), or no solution (group Ctrl). All solutions were provided from the day of surgery until sacrifice on day three. Plasma concentrations of diclofenac were determined. Outcomes were anastomotic leakage, leak severity, and anastomotic strength. RESULTS: Anastomotic leak rates were 89% in group DCF and 44% in group DCF-Inh1 (p = 0.006). Leak severity was reduced in group DCFic-Inh1 (p = 0.029). In non-diclofenac cohorts, mostly minor leakage signs were observed in 25% in group Ctrl, 39% in group Inh1 (0.477), and 24% in group Veh (p = 1.000). Bursting pressure and breaking strength were not significantly different. Plasma concentrations of diclofenac were not changed by Inh1. CONCLUSION: Microbial glucuronidase inhibitor reduces diclofenac-induced anastomotic leakage severity, which suggests a harmful effect of diclofenac metabolite reactivation in the gut. This finding improves the understanding of the pathogenesis of anastomotic leakage.