Gut microbiota influence anastomotic healing in colorectal cancer surgery through modulation of mucosal proinflammatory cytokines.

OBJECTIVE: Colorectal cancer (CRC) is the third most diagnosed cancer, and requires surgical resection and reconnection, or anastomosis, of the remaining bowel to re-establish intestinal continuity. Anastomotic leak (AL) is a major complication that increases mortality and cancer recurrence. Our objective is to assess the causal role of gut microbiota in anastomotic healing. DESIGN: The causal role of gut microbiota was assessed in a murine AL model receiving faecal microbiota transplantation (FMT) from patients with CRC collected before surgery and who later developed or not, AL. Anastomotic healing and gut barrier integrity were assessed after surgery. Bacterial candidates implicated in anastomotic healing were identified using 16S rRNA gene sequencing and were isolated from faecal samples to be tested both in vitro and in vivo. RESULTS: Mice receiving FMT from patients that developed AL displayed poor anastomotic healing. Profiling of gut microbiota of patients and mice after FMT revealed correlations between healing parameters and the relative abundance of Alistipes onderdonkii and Parabacteroides goldsteinii. Oral supplementation with A. onderdonkii resulted in a higher rate of leaks in mice, while gavage with P. goldsteinii improved healing by exerting an anti-inflammatory effect. Patients with AL and mice receiving FMT from AL patients presented upregulation of mucosal MIP-1α, MIP-2, MCP-1 and IL-17A/F before surgery. Retrospective analysis revealed that patients with AL present higher circulating neutrophil and monocyte counts before surgery. CONCLUSION: Gut microbiota plays an important role in surgical colonic healing in patients with CRC. The impact of these findings may extend to a vast array of invasive gastrointestinal procedures.

Crohn's Disease after Proctocolectomy and IPAA for Ulcerative Colitis.

BACKGROUND: Proctocolectomy with IPAA is considered curative for ulcerative colitis. However, signs of Crohn's disease can develop postoperatively in some cases. OBJECTIVE: Our aim was to document the postoperative diagnosis of Crohn's disease, to identify potential preoperative predictive factors, and to review the evolution of patients on treatment. DESIGN: This is a retrospective cohort study. SETTINGS: This study was conducted at a tertiary care center in Montreal, Canada. PATIENTS: A total of 301 patients underwent an IPAA for ulcerative colitis between 1985 and 2014. MAIN OUTCOME MEASURES: The primary outcome was the cumulative incidence of the postoperative diagnosis of Crohn's disease. RESULTS: During a median follow-up of 68 months, Crohn's disease was diagnosed at a median time of 77 months (8-270) in 38 patients (12.6%). The cumulative incidence of Crohn's disease was 7.5% at 5 years postoperatively and gradually increased to 17.7% and 33.0% at 10 and 20 years. The following predictive factors for Crohn's disease were observed on univariate analysis: current tobacco smoking at surgery (HR 3.56 (95% CI, 1.54-8.22)), suspicion of indeterminate colitis (HR 3.50 (95% CI, 1.69-7.24)), presence of mouth ulcers before surgery (HR 2.16 (95% CI, 1.03-4.53)), and age at diagnosis of ulcerative colitis (HR 0.94 (95% CI, 0.90-0.97)). Suspicion of indeterminate colitis (HR 3.18 (95% CI 1.46-6.93); p = 0.004) and age at diagnosis (HR 0.95 (95% CI, 0.91-0.99); p = 0.018) remained statistically significant on multivariate analysis. Postoperative inflammatory disease was controlled by medical therapy in most patients. Removal of the pouch was necessary in 16% of patients with Crohn's disease. LIMITATIONS: This was a retrospective single-center study. CONCLUSIONS: Diagnosis of Crohn's disease can occur at a distance from surgery with an increasing cumulative incidence over time. Preoperative predictive factors are few and should not determine candidacy for surgery. Therapeutic options are identical to those available for treatment of typical Crohn's disease and allow a favorable evolution in most patients. See Video Abstract at http://links.lww.com/DCR/B372. BROTE DE CROHN DESPUS DE UNA PROCTOCOLECTOMA CON ANASTOMOSIS DE RESERVORIO LEOANAL EN CASOS DE COLITIS ULCEROSA: ANTECEDENTES:La proctocolectomía con reservorio ileo-anal se considera curativa para la colitis ulcerosa. Sin embargo, signos de enfermedad de Crohn pueden desarrollarse después de la operación en algunos casos.OBJETIVO:Nuestro objetivo fue documentar el diagnóstico postoperatorio de la enfermedad de Crohn, identificar posibles factores predictivos preoperatorios y revisar la evolución de los pacientes con tratamiento.DISEÑO:Estudio retrospectivo de cohortes.AJUSTES:Centro de atención terciaria en Montreal, Canadá.PACIENTES:301 pacientes portadores de un reservorio íleo-anal realizados por colitis ulcerosa entre 1985 y 2014.PRINCIPALES MEDIDAS DE RESULTADO:Acumulación de la incidencia en el diagnóstico postoperatorio de enfermedad de Crohn.RESULTADOS:Durante una media de 68 meses de seguimiento, la enfermedad de Crohn fué diagnosticada en un tiempo medio de 77 meses (8-270) en 38 pacientes (12,6%). La acumulación de incidencia de la enfermedad de Crohn fue del 7,5% a los 5 años después de la operación y aumentó gradualmente a 17,7 y 33,0% a los 10 y 20 años. Los siguientes factores predictivos para la enfermedad de Crohn se observaron en el análisis univariado: tabaquismo activo al momento de la cirugía (cociente de riesgo (HR) 3.56 (intervalo de confianza del 95% (IC) 1.54-8.22)), sospecha de colitis indeterminada (HR 3.50 (IC del 95% 1.69-7.24)), presencia de úlceras en la boca antes de la cirugía (HR 2.16 (IC 95% 1.03-4.53)) y edad al diagnóstico de colitis ulcerosa (HR 0.94 (IC 95% 0.90-0.97)). La sospecha de colitis indeterminada (HR 3.18 (IC 95% 1.46-6.93), p = 0.004) y la edad al momento del diagnóstico (HR 0.95 (IC 95% 0.91-0.99), p = 0.018) permanecieron estadísticamente significativos en el análisis multivariado. La reacción inflamatoria intestinal postoperatoria fue controlada con tratamiento médico en la mayoría de los pacientes. El retiro del reservorio íleo-anal fue necesario en 16% de los pacientes con enfermedad de Crohn.LIMITACIONES:Estudio retrospectivo de centro único.CONCLUSIONES:El diagnóstico de la enfermedad de Crohn puede ocurrir a distancia de la cirugía con la acumulación de incidencia creciente con el tiempo. Los factores predictivos preo-peratorios son pocos y no pueden determinar la candidatura para la cirugía. Las opciones terapéuticas son idénticas a las disponibles para el tratamiento de la enfermedad de Crohn típica y permiten una evolución favorable en la mayoría de los pacientes. Consulte Video Resumen en http://links.lww.com/DCR/B372. (Traducción-Dr. Xavier Delgadillo).

Human basophils interact with memory T cells to augment Th17 responses.

Basophils are a rare population of granulocytes that have long been associated with IgE-mediated and Th2-associated allergic diseases. However, the role of basophils in Th17 and/or Th1 diseases has not been reported. In the present study, we report that basophils can be detected in the mucosa of Th17-associated lung and inflammatory bowel disease and accumulate in inflamed colons containing large quantities of IL-33. We also demonstrate that circulating basophils increased memory Th17 responses. Accordingly, IL-3- or IL-33-activated basophils amplified IL-17 release in effector memory T cells (T(EM)), central memory T cells (T(CM)), and CCR6(+) CD4 T cells. More specifically, basophils promoted the emergence of IL-17(+)IFN-γ(-) and IL-17(+)IFN-γ(+), but not IL-17(-)IFN-γ(+) CD4 T cells in T(EM) and T(CM). Mechanistic analysis revealed that the enhancing effect of IL-17 production by basophils in T(EM) involved the ERK1/2 signaling pathway, occurred in a contact-independent manner, and was partially mediated by histamine via H(2) and H(4) histamine receptors. The results of the present study reveal a previously unknown function for basophils in augmenting Th17 and Th17/Th1 cytokine expression in memory CD4 T cells. Because basophils accumulated in inflamed inflammatory bowel disease tissues, we propose that these cells are key players in chronic inflammatory disorders beyond Th2.

Modulating Gut Microbiota Prevents Anastomotic Leak to Reduce Local Implantation and Dissemination of Colorectal Cancer Cells after Surgery.

PURPOSE: Anastomotic leak (AL) is a major complication in colorectal cancer surgery and consists of the leakage of intestinal content through a poorly healed colonic wound. Colorectal cancer recurrence after surgery is a major determinant of survival. We hypothesize that AL may allow cancer cells to escape the gut and lead to cancer recurrence and that improving anastomotic healing may prevent local implantation and metastatic dissemination of cancer cells. EXPERIMENTAL DESIGN: We investigated the association between AL and postoperative outcomes in patients with colorectal cancer. Using mouse models of poor anastomotic healing, we assessed the processes of local implantation and dissemination of cancer cells. The effect of dietary supplementation with inulin and 5-aminosalicylate (5-ASA), which activate PPAR-γ in the gut, on local anastomotic tumors was assessed in mice undergoing colonic surgery. Inulin and 5-ASA were also assessed in a mouse model of liver metastasis. RESULTS: Patients experiencing AL displayed lower overall and oncologic survival than non-AL patients. Poor anastomotic healing in mice led to larger anastomotic and peritoneal tumors. The microbiota of patients with AL displays a lower capacity to activate the antineoplastic PPAR-γ in the gut. Modulation of gut microbiota using dietary inulin and 5-ASA reinforced the gut barrier and prevented anastomotic tumors and metastatic spread in mice. CONCLUSIONS: Our findings reinforce the hypothesis that preventing AL is paramount to improving oncologic outcomes after colorectal cancer surgery. Furthermore, they pave the way toward dietary targeting of PPAR-γ as a novel way to enhance healing and diminish cancer recurrence.

Putrescine supplementation limits the expansion of pks+ Escherichia coli and tumor development in the colon.

Escherichia coli that harbor the polyketide synthase (pks) genomic island produce colibactin and are associated with sporadic colorectal cancer development (CRC). Given the considerable prevalence of pks+ bacteria in healthy individuals, we sought to identify strategies to limit the growth and expansion of pks+ E. coli. We found that culture supernatants of the probiotic strain E. coli Nissle 1917 were able to inhibit the growth of the murine pathogenic strain pks+ E. coli NC101 (EcNC101). We performed a non-targeted analysis of the metabolome in supernatants from several E. coli strains and identified putrescine as a potential postbiotic capable of suppressing EcNC101 growth in vitro. The effect of putrescine supplementation was then evaluated in the azoxymethane (AOM)/dextran sulfate sodium (DSS) mouse model of CRC in mice colonized with EcNC101. Putrescine supplementation inhibited the growth of pks+ E. coli; reduced the number and size of colonic tumors; and downmodulated the release of inflammatory cytokines in the colonic lumen. Additionally, putrescine supplementation led to shifts in the composition and function of gut microbiota, characterized by an increase of the Firmicutes/Bacteroidetes ratio and enhanced acetate production. The effect of putrescine was further confirmed in vitro using a pks+ E. coli strain isolated from a CRC patient. These results suggest that probiotic-derived metabolites can be used as an alternative to live bacteria in individuals at risk of developing CRC due to the presence of pks+ bacteria in their colon.

Safety and clinical efficacy of EUS-guided pelvic abscess drainage.

Background and Objectives: EUS is a potential alternative for the drainage of abscesses. The aim of this study was to determine if EUS-guided pelvic abscess drainage is technically feasible, safe, and a valid option for abscess resolution. Methods: We conducted a retrospective review from 2002 to 2020 at a single quaternary institution. EUS-guided pelvic abscess drainage via the transrectal route was performed in all patients with or without drain/stent placement. Technical and clinical success of EUS-guided pelvic abscess drainage was analyzed. Descriptive analyses and Fisher exact test were performed. Results: Sixty consecutive patients were included in the study (53.5% male; mean age, 53.8 ± 17.9 years). Pelvic abscesses occurred mainly postoperatively (33 cases; 60.0%) and from complicated diverticulitis (14 cases; 23.3%). Mean diameter was 6.5 ± 2.4 cm (80% unilocular). Drainage was performed with EUS-guided stent placement (double-pigtail plastic or lumen-apposing metal) in 74.5% of cases and with aspiration alone for the remainder. Technical success occurred in 58 cases (97%). Of those with long-term follow-up after EUS-guided pelvic abscess drainage (n = 55; 91.7%), complete abscess resolution occurred in 72.7% of all cases. Recurrence occurred in 8 cases (14.5%) and persisted in 7 patients (12.5%), 7 of which were successfully retreated with EUS-guided pelvic abscess drainage. Accounting for these successful reinterventions, the overall rate of abscess resolution was 85.5%. Abscess resolution rate improved with drain placement (83%). Accounting for 7 repeat EUS-guided pelvic abscess drainages, overall abscess resolution improved. Two deaths occurred (3.4%) because of sepsis from failed source control in patients who had previously failed medical, radiological, and surgical treatment. Conclusions: EUS-guided pelvic abscess drainage is technically feasible, safe, and an effective alternative to radiological or open surgical drainage. It also offers favorable clinical outcomes in different clinical situations.

Prevalence of pks + bacteria and enterotoxigenic Bacteroides fragilis in patients with colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is the third most diagnosed cancer and the second most common cause of cancer deaths worldwide. CRC patients present with an increase in pathogens in their gut microbiota, such as polyketide synthase-positive bacteria (pks +) and enterotoxigenic Bacteroides fragilis (ETBF). The pks + Escherichia coli promotes carcinogenesis and facilitates CRC progression through the production of colibactin, a genotoxin that induces double-strand DNA breaks (DSBs). ETBF is a procarcinogenic bacterium producing the B. fragilis toxin (bft) that promotes colorectal carcinogenesis by modulating the mucosal immune response and inducing epithelial cell changes. METHODS: Fecal samples were collected from healthy controls (N = 62) and CRC patients (N = 94) from the province of Québec (Canada), and a bacterial DNA extraction was performed. Fecal DNA samples were then examined for the presence of the pks island gene and bft using conventional qualitative PCR. RESULTS: We found that a high proportion of healthy controls are colonized by pks + bacteria (42%) and that these levels were similar in CRC patients (46%). bft was detected in 21% of healthy controls and 32% of CRC patients, while double colonization by both pks + bacteria and ETBF occurred in 8% of the healthy controls and 13% of the CRC patients. Most importantly, we found that early-onset CRC (< 50 years) patients were significantly less colonized with pks + bacteria (20%) compared to late-onset CRC patients (52%). CONCLUSIONS: Healthy controls had similar levels of pks + bacteria and ETBF colonization as CRC patients, and their elevated levels may place both groups at greater risk of developing CRC. Colonization with pks + bacteria was less prevalent in early-compared to late-onset CRC.

Comparing the effectiveness of simulation as adjuncts to standardized lectures, on the identification and reporting of intimidation during surgical clerkship: A mixed method randomized controlled trial.

BACKGROUND: Intimidation constitutes a learning barrier for undergraduates and its reporting rate to authorities remains suboptimal. METHODS: A randomized controlled trial was conducted to evaluate the effectiveness of three interventions designed to increase reporting by undergraduates during their surgical rotation. As adjuncts to a standardized lecture, participants were assigned to a simulated intimidation scenario, a video of intimidation events, or a control group. Surveys were completed before the interventions, and at the end of the rotation. RESULTS: Of the 119 included participants, 17.6% reported that they had been intimidated during their previous rotation as compared to 37.0% after the surgical rotation. There were no statistically significant differences in the reporting of intimidation between the groups. However, 65.5% of all participants declared feeling more at ease to report intimidation, yet the reporting rate remained low. CONCLUSION: Intimidation during clerkship persists as a frequent problem although the best method to increase its reporting remains unclear.

Transcriptomic Analysis and High-dimensional Phenotypic Mapping of Mononuclear Phagocytes in Mesenteric Lymph Nodes Reveal Differences Between Ulcerative Colitis and Crohn's Disease.

BACKGROUND AND AIMS: Crohn's disease [CD] and ulcerative colitis [UC] are distinct forms of inflammatory bowel disease. Heterogeneity of HLA-DR+SIRPα + mononuclear phagocytes [MNPs], including macrophages [MΦ], monocyte-derived [Mono] cells, and dendritic cells [DCs], was reported in gut tissue but not yet investigated in mesenteric lymph nodes [MLNs] of IBD patients. We here compared the phenotype, function, and molecular profile of HLA-DR+SIRPα + MNPs in CD and UC MLNs. METHODS: Cell distribution, morphology, immune function, and transcriptomic [bulk RNAseq] and high-dimensional protein expression profiles [CyTOF] of HLA-DR+SIRPα + MNPs were examined in MLNs of UC [n = 14], CD [n = 35], and non-IBD [n = 12] patients. RESULTS: Elevated frequencies of CD14+CD64+CD163+ [Mono/MΦ-like] MNPs displaying monocyte/MΦ morphology and phagocytic function were a distinct feature of UC MLNs. In CD, the proportion of CD14-CD64-CD163- [DC-like] cells was augmented relative to Mono/MΦ-like cells; DC-like cells drove naïve T cell proliferation, Th1 polarisation, and Th17 TCM plasticity. Gene expression profile corroborated the nature of DC-like cells, best represented by BTLA, SERPINF, IGJ and, of Mono/MΦ-like cells, defined by CD163, MARCO, MAFB, CD300E, S100A9 expression. CyTOF analysis showed that CD123+ plasmacytoid cells predominated over conventional DCs in DC-like cells. Four CD163+ clusters were revealed in Mono/MΦ-like cells, two of which were enriched in MARCO-CD68dimHLA-DRdim monocyte-like cells and MARCOhiCD68hiHLA-DRhi Mɸ, whose proportion increased in UC relative to CD. CONCLUSIONS: Defining the landscape of MNPs in MLNs provided evidence for expansion of CD163+ Mono/MΦ-like cells in UC only, highlighting a distinction between UC and CD, and thus the potential contribution of monocyte-like cells in driving colitis.

Differential Pathogenic Th17 Profile in Mesenteric Lymph Nodes of Crohn's Disease and Ulcerative Colitis Patients.

The drug targets IL23 and IL12 regulate pathogenicity and plasticity of intestinal Th17 cells in Crohn's disease (CD) and ulcerative colitis (UC), the two most common inflammatory bowel diseases (IBD). However, studies examining Th17 dysregulation in mesenteric lymph nodes (mLNs) of these patients are rare. We showed that in mLNs, CD could be distinguished from UC by increased frequencies of CCR6+CXCR3-RORγ+Tbet-CD4+ (Th17) memory T cells enriched in CD62Llow effector memory T cells (TEM), and their differentially expressed molecular profile. Th17 TEM cells (expressing IL17A, IL17F, RORC, and STAT3) displayed a higher pathogenic/cytotoxic (IL23R, IL18RAP, and GZMB, CD160, PRF1) gene signature in CD relative to UC, while non-pathogenic/regulatory genes (IL9, FOXP3, CTLA4) were more elevated in UC. In both CD and UC, IL12 but not IL23, augmented IFNγ expression in Th17 TEM and switched their molecular profile toward an ex-Th17 (Th1*)-biased transcriptomic signature (increased IFNG, and decreased TCF7, IL17A), suggesting that Th17 plasticity occurs in mLNs before their recruitment to inflamed colon. We propose that differences observed between Th17 cell frequencies and their molecular profile in CD and UC might have implications in understanding disease pathogenesis, and thus, therapeutic management of patients with IBD.

Transjugular intrahepatic portosystemic shunt before abdominal surgery in cirrhotic patients: a retrospective, comparative study.

Surgery in cirrhotic patients is associated with high morbidity and mortality related to portal hypertension and liver insufficiency. Therefore, preoperative portal decompression is a logical approach to facilitate abdominal surgery and hopefully to improve postoperative survival. The present study evaluated the clinical outcomes of 18 patients (mean age 58 years) with cirrhosis (seven alcoholics and 11 nonalcoholics) who underwent transjugular intrahepatic portosystemic shunt (TIPS) placement before antrectomy (n=5), colectomy (n=10), small-bowel resection (n=1), pancreatectomy (n=1) and nephrectomy (n=1). TIPS was performed a mean (+/-SD) of 72+/-21 days before surgery and induced a marked mean decrease in portohepatic gradient from 21.4+/-3.9 mmHg to 8.4+/-3.4 mmHg. Cirrhotic patients (n=17) who underwent elective abdominal surgery without preoperative TIPS placement were used as the control group. Both groups were matched for age, etiology of cirrhosis, indications for surgery, type of surgery and coagulation parameters. The mean Pugh score was significantly higher in the TIPS group (7.7 versus 6.2). No significant differences were observed for operative blood loss, postoperative complications, duration of hospitalization and one-month (83% versus 88%) or one-year (54% versus 63%) cumulative survival rate. Analysis using the Cox proportional hazards model showed that neither TIPS placement nor preoperative Pugh score were independent predictors for survival. The present study suggests that preoperative TIPS placement does not improve postoperative evolution after abdominal surgery in cirrhotic patients with good or moderately impaired liver function.

Differential accumulation and function of proinflammatory 6-sulfo LacNAc dendritic cells in lymph node and colon of Crohn's versus ulcerative colitis patients.

Human Slan DCs have been studied in patients with psoriasis, rheumatoid arthritis, cancer, and autoimmune diseases. In this study, we investigated the frequency, phenotype, and function of Slan DCs in blood, colon, as well as mLNs of patients with IBD. We first show that the frequency of circulating CD14(dull)Slan DCs was reduced in CD patients refractory to immunosuppressive drugs or TNF-α blockers relative to untreated CD, UC, and healthy subjects. In blood of CD patients, Slan DCs expressed CD172a, as detected by CD47 fusion protein binding, when compared with its lack of expression in control subjects. Next, we demonstrate that CD172a(+)Slan DCs that produced IL-1ß and TNF-α accumulated in mLNs and colons of CD patients. The CD172a(+)Slan DCs up-regulated their expression of CD14 in CD tissues and the proinflammatory cytokines were produced in CD14(bright)CD172a(+)Slan DCs. By contrast, no difference was noted in the frequency of Slan DCs between inflamed, noninflamed colonic mucosa of UC patients and control, non-IBD donors. Finally, the percentage of cytokine-producing Slan DCs also augmented in response to TLR2 and NOD2 in in vitro stimulation in PBMCs of CD, but not UC, patients. In conclusion, we propose that proinflammatory CD14(bright)CD172a(+)Slan DCs are a distinguishing feature between CD and UC, as these cells accumulate uniquely in mLNs and colonic mucosa of CD patients. Thus, Slan DCs may contribute to CD immunopathogenesis.

CD47 fusion protein targets CD172a+ cells in Crohn's disease and dampens the production of IL-1ß and TNF.

In mice, the transfer of CD172a(+) (SIRP-α) dendritic cells (DCs) elicits T cell-driven colitis, whereas treatment with CD47-Fc protein, a CD172a-binding agent, confers protection. The aim of this study was to elucidate the nature and functional properties of human CD172a(+) DCs in chronic intestinal inflammation. Here, we show that CD172a(+)CD11c(+) cells accumulate in the mesenteric lymph nodes (mLNs) and inflamed intestinal mucosa in patients with Crohn's disease (CD). These cells are distinct from resident DCs and may coexpress markers typically associated with monocyte-derived inflammatory DCs such as CD14 and/or DC-SIGN, E-Cadherin, and/or CX3CR1. Spontaneous IL-1ß and TNF production by HLA-DR(+) cells in CD tissues is restricted to those expressing CD172a. An avidity-improved CD47 fusion protein (CD47-Var1) suppresses the release of a wide array of inflammatory cytokines by CD172a(+) cells, which may include HLA-DR(-)CD172a(+) neutrophils, in inflamed colonic explant cultures and impairs the ability of HLA-DR(+)CD172a(+) cells to activate memory Th17 but not Th1 responses in mLNs. In conclusion, targeting CD172a(+) cells may represent novel therapeutic perspectives for patients with CD.