Surgical Management of Inflammatory Bowel Disease

Bile acid-gut microbiota imbalance in cholestasis and its long-term effect in mice

Cholestasis is a common morbid state that may occur in different phases; however, a comprehensive evaluation of the long-term effect post-recovery is still lacking. In the hepatic cholestasis mouse model, which was induced by a temporary complete blockage of the bile duct, the stasis of bile acids and liver damage typically recovered within a short period. However, we found that the temporary hepatic cholestasis had a long-term effect on gut microbiota dysbiosis, including overgrowth of small intestinal bacteria, decreased diversity of the gut microbiota, and an overall imbalance in its composition accompanied by an elevated inflammation level. Additionally, we observed an increase in Escherichia-Shigella (represented by ASV136078), rich in virulence factors, in both small and large intestines following cholestasis. To confirm the causal role of dysregulated gut microbiota in promoting hepatic inflammation and injury, we conducted gut microbiota transplantation into germ-free mice. We found that recipient mice transplanted with feces from cholestasis mice exhibited liver inflammation, damage, and accumulation of hepatic bile acids. In conclusion, our study demonstrates that cholestasis disrupts the overall load and structural composition of the gut microbiota in mice, and these adverse effects persist after recovery from cholestatic liver injury. This finding suggests the importance of monitoring the structural composition of the gut microbiota in patients with cholestasis and during their recovery.

IMPORTANCE

Our pre-clinical study using a mouse model of cholestasis underscores that cholestasis not only disrupts the equilibrium and structural configuration of the gut microbiota but also emphasizes the persistence of these adverse effects even after bile stasis restoration. This suggests the need of monitoring and initiating interventions for gut microbiota structural restoration in patients with cholestasis during and after recovery. We believe that our study contributes to novel and better understanding of the intricate interplay among bile acid homeostasis, gut microbiota, and cholestasis-associated complications. Our pre-clinical findings may provide implications for the clinical management of patients with cholestasis.

Interaction of gut microbiota with bile acid metabolism and its influence on disease states

Primary bile acids serve important roles in cholesterol metabolism, lipid digestion, host-microbe interactions, and regulatory pathways in the human host. While most bile acids are reabsorbed and recycled via enterohepatic cycling, ∼5% serve as substrates for bacterial biotransformation in the colon. Enzymes involved in various transformations have been characterized from cultured gut bacteria and reveal taxa-specific distribution. More recently, bioinformatic approaches have revealed greater diversity in isoforms of these enzymes, and the microbial species in which they are found. Thus, the functional roles played by the bile acid-transforming gut microbiota and the distribution of resulting secondary bile acids, in the bile acid pool, may be profoundly affected by microbial community structure and function. Bile acids and the composition of the bile acid pool have historically been hypothesized to be associated with several disease states, including recurrent Clostridium difficile infection, inflammatory bowel diseases, metabolic syndrome, and several cancers. Recently, however, emphasis has been placed on how microbial communities in the dysbiotic gut may alter the bile acid pool to potentially cause or mitigate disease onset. This review highlights the current understanding of the interactions between the gut microbial community, bile acid biotransformation, and disease states, and addresses future directions to better understand these complex associations.

Outcome following infliximab therapy in children with ulcerative colitis

OBJECTIVES

Infliximab is effective in treating moderate/severe ulcerative colitis (UC) in adults. The aim of this study was to determine the outcome after treatment with infliximab in pediatric UC.

METHODS

We performed a multicenter cohort study of 332 pediatric patients with UC enrolled in the Pediatric Inflammatory Bowel Disease Collaborative Research Group Registry. Children<or=16 years of age and newly diagnosed with UC are enrolled in the registry. Disease and medication information are collected prospectively from the treating physician at diagnosis, 30 days, and quarterly thereafter. No interventions were specified, per protocol.

RESULTS

Of 332 patients, 52 (16%) received infliximab (23%<3 months from diagnosis, 38% 3-12 months, 38% >12 months). Mean age at infliximab initiation was 13.3+/-2.6 (range 6-17) years; 87% of patients had pancolitis. Median follow-up was 30 months. Continuous maintenance (CM) therapy was given in 65%, episodic in 21%, episodic converted to CM in 6%, and insufficient data in 8% of patients. Sixty-three percent of patients were corticosteroid refractory, and 35% were corticosteroid dependent. Concomitant medications at first infliximab infusion included corticosteroids (87%), thiopurines (63%), and 5-aminosalicylates (51%). Corticosteroid-free inactive disease by physician global assessment was noted in 12/44 (27%), 15/39 (38%), and 6/28 (21%) patients at 6, 12, and 24 months, respectively. Kaplan-Meier analysis showed that the likelihood of remaining colectomy free after treatment with infliximab was 75% at 6 months, 72% at 12 months, and 61% at 2 years.

CONCLUSIONS

In this cohort of children with UC receiving infliximab, corticosteroid-free inactive disease was observed in 38 and 21% of patients at 12 and 24 months, respectively. By 24 months, 61% of patients had avoided colectomy.

Safety and efficacy of strictureplasty for Crohn's disease: a systematic review and meta-analysis

PURPOSE

This study was designed to review safety and efficacy of strictureplasty for Crohn's disease.

METHODS

A literature search was performed to identify studies published between 1975 and 2005 that reported the outcome of strictureplasty. Systematic review was performed on the following subjects separately: 1) overall experience of strictureplasty; 2) postoperative complications; 3) postoperative recurrence and site of recurrence; 4) factors affecting postoperative complications and recurrence; 5) short-bowel syndrome; and 6) cancer risk. Meta-analysis of recurrence rate after strictureplasty was performed by using random-effect model and meta-regressive techniques.

RESULTS

A total of 1,112 patients who underwent 3,259 strictureplasties (Heineke-Mikulicz, 81 percent; Finney, 10 percent; side-to-side isoperistaltic, 5 percent) were identified. The sites of strictureplasty were jejunum and/or ileum (94 percent), previous anastomosis (4 percent), duodenum (1 percent), and colon (1 percent). After jejunoileal strictureplasty, including ileocolonic strictureplasty, septic complications (leak/fistula/abscess) occurred in 4 percent of patients. Overall surgical recurrence was 23 percent (95 percent confidence interval, 17-30 percent). Using meta-regressive analysis, the five-year recurrence rate after strictureplasty was 28 percent. In 90 percent of patients, recurrence occurred at nonstrictureplasty sites, and the site-specific recurrence rate was 3 percent. Two patients developed adenocarcinoma at the site of previous jejunoileal strictureplasty. The experience of duodenal or colonic strictureplasty was limited.

CONCLUSIONS

Strictureplasty is a safe and effective procedure for jejunoileal Crohn's disease, including ileocolonic recurrence, and it has the advantage of protecting against further small bowel loss. However, the place for strictureplasty is less well defined in duodenal and colonic diseases.

Strictureplasty vs resection in small bowel Crohn's disease: an evaluation of short-term outcomes and recurrence

AIM

To compare postoperative adverse events and recurrence following strictureplasty or bowel resection in patients with small bowel Crohn's disease (CD).

METHOD

A literature search was performed to identify studies published between 1980 and 2006 comparing outcomes of CD patients undergoing either strictureplasty or bowel resection. Hazard ratios were calculated from Kaplan-Meier plots of cumulative recurrence data. Quality assessment of the included studies was performed. Random-effect meta-analytical techniques were employed. Sensitivity analysis and assessment of heterogeneity were performed.

RESULTS

Seven studies comprising 688 CD patients (strictureplasty n = 311, 45%; resection with or without strictureplasty n = 377, 55%) were included. Patients undergoing strictureplasty alone had a lower risk of developing postoperative complications than those who underwent resection (OR = 0.60, 95% CI: 0.31-1.16) although this was not statistically significant (P = 0.13). Surgical recurrence after strictureplasty was more likely than after resection (OR = 1.36, 95% CI: 0.96-1.93, P = 0.09). Patients who had a resection had a significantly longer recurrence-free survival than those undergoing strictureplasty alone (HR = 1.08, 95% CI: 1.02-1.15, P = 0.01).

CONCLUSION

Patients with small bowel CD undergoing strictureplasty alone may have fewer postoperative complications than those undergoing a concomitant bowel resection. However, surgical recurrence maybe higher following strictureplasty alone than with a concomitant small bowel resection. Patients may require appropriate preoperative counselling regarding the pros and cons of each operative technique.