Role of intestinal bacteria in the pathogenesis of pouchitis

Ouch, my pouch! a clinician's guide to pouchitis

Pouchitis is defined as inflammation of the ileal pouch created during a restorative proctocolectomy with ileal pouch-anal anastomosis. Although the incidence of this inflammatory condition is high, the exact etiology often remains unclear and the management challenging. In this review, we summarize the clinical presentation, pathogenesis, diagnosis, and management of this common complication.

A Systematic Review and Meta-analysis of Randomized Clinical Trials on the Prevention and Treatment of Pouchitis after Ileoanal Pouch Anastomosis

BACKGROUND

This systematic review explored different medications and methods for prevention and treatment of pouchitis after restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA).

METHODS

PubMed, Scopus, and Web of Science were searched for randomized clinical trials that assessed prevention or treatment of pouchitis. The systematic review was reported in line with updated 2020 PRISMA guidelines. Risk of bias in the trials included was assessed using the ROB-2 tool and certainty of evidence was assessed using GRADE. The main outcomes were the incidence of new pouchitis episodes in the preventative studies and resolution or improvement of active pouchitis in the treatment studies.

RESULTS

Fifteen randomized trials were included. A meta-analysis of 7 trials on probiotics revealed significantly lower odds of pouchitis with the use of probiotics (RR: 0.26, 95% CI: 0.16-0.42, I2 = 20%, p < 0.001) and similar odds of adverse effects to placebo (RR: 2.43, 95% CI: 0.11-55.9, I2 = 0, p = 0.579). One trial investigated the prophylactic role of allopurinol in preventing pouchitis and found a comparable incidence of pouchitis in the two groups (31% vs 28%; p = 0.73). Seven trials assessed different treatments for active pouchitis. One recorded the resolution of pouchitis in all patients treated with ciprofloxacin versus 67% treated with metronidazole. Both budesonide enema and oral metronidazole were associated with similar significant improvement in pouchitis (58.3% vs 50%, p = 0.67). Rifaximin, adalimumab, fecal microbiota transplantation, and bismuth carbomer foam enema were not effective in treating pouchitis.

CONCLUSIONS

Probiotics are effective in preventing pouchitis after IPAA. Antibiotics, including ciprofloxacin and metronidazole, are likely effective in treating active pouchitis.

Classification and Management of Disorders of the J Pouch

Total abdominal proctocolectomy with ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC) is associated with substantial complications despite the benefits of managing refractory and/or neoplasia-associated disease. For the purpose of this review, we focused on the diagnosis of some of the most common inflammatory and structural pouch disorders and their respective management. Pouchitis is the most common complication, and it is typically responsive to antibiotics. However, chronic antibiotic refractory pouchitis (CARP) has been increasingly recognized, and biologic therapies have emerged as the mainstay of therapy. Crohn's-like disease of the pouch (CLDP) can affect up to 10% of patients with UC after IPAA. Medical options are similar to CARP therapies, including biologics with immunomodulators. Studies have shown higher efficacy rates of biologics for CLDP when compared with those for CARP. In addition, managing stricturing and fistulizing CLDP is challenging and often requires interventional endoscopy (balloon dilation and/or stricturotomy) and/or surgery. The implementation of standardized diagnostic criteria for inflammatory pouch disorders will help in advancing future therapeutic options. Structural pouch disorders are commonly related to surgical complications after IPAA. We focused on the diagnosis and management of anastomotic leaks, strictures, and floppy pouch complex. Anastomotic leaks and anastomotic strictures occur in approximately 15% and 11% of patients with UC after IPAA, respectively. Further complications from pouch leaks include the development of sinuses, fistulas, and pouch sepsis requiring excision. Novel endoscopic interventions and less invasive surgical procedures have emerged as options for the management of these disorders.

Very Early Pouchitis Is Associated with an Increased Likelihood of Chronic Inflammatory Conditions of the Pouch

INTRODUCTION

Chronic inflammatory conditions of the pouch are common after ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC).

AIMS

We aimed to investigate the relationship between acute pouchitis within 180 days of the final stage of IPAA surgery (very early pouchitis) and the future development of chronic antibiotic dependent pouchitis (CADP) and Crohn's-like disease of the pouch (CLDP).

METHODS

We performed a retrospective cohort study, evaluating patients who underwent proctocolectomy with IPAA between January 1, 2004 and December 31, 2016. Multivariable logistic regression was used to evaluate the relationship between very early pouchitis and the development of CADP and CLDP.

RESULTS

Among 626 patients undergoing IPAA for UC, 137 (22%) developed very early pouchitis, 75 (12%) developed CADP, and 59 (9%) developed CLDP in a median follow-up of 5.18 years (interquartile range 0.94-10.8 years). Very early pouchitis was associated with a significant increase in the odds of developing CADP (adjusted odds ratio [aOR3.65, 95% CI 2.19-6.10) as was primary sclerosing cholangitis (aOR 3.97, 95% CI 1.44-11.0). Very early pouchitis was associated with increased odds for developing CLDP (aOR 2.77, 95% CI 1.54-4.98) along with a family history of inflammatory bowel disease (aOR 2.10, 95% CI 1.11-3.96).

CONCLUSION

In this cohort, very early pouchitis was associated with an increased risk of developing CADP and CLDP. These findings highlight very early pouchitis as a unique risk factor for chronic inflammatory conditions of the pouch and the need for future studies evaluating potential strategies for secondary prophylaxis strategies in this population.

Relationship Between Stages of Ileal Pouch-Anal Anastomosis, Timing of Restoration of Fecal Continuity, and Pouchitis

BACKGROUND

The most common complication following ileal pouch-anal anastomosis (IPAA) in patients with ulcerative colitis (UC) is pouchitis.

AIMS

We aimed to investigate whether a shorter period between pouch creation and restoration of fecal flow through an IPAA was associated with an increased risk of development of pouchitis within the first 2 years after IPAA.

METHODS

We performed a retrospective cohort study evaluating patients undergoing colectomy with IPAA for UC between January 1, 2004 and December 31, 2016. We used Kaplan-Meier testing and Cox Proportional Hazards Modeling to evaluate the relationship between the time between restoration of fecal continuity and time to subsequent development of pouchitis, adjusting for other clinical and demographic factors.

RESULTS

We identified 624 patients who underwent proctocolectomy with IPAA for UC, of whom 246 (39%) developed pouchitis within the first 2 years after IPAA. There was no difference when comparing the median time to restoration of continuity among those patients who developed pouchitis and those who did not (49 days vs. 49 days, p = 0.85) or in multivariable analysis. Primary sclerosing cholangitis (Hazard Ratio [HR] 2.14, 95% CI 1.12-4.08), family history of inflammatory bowel disease (HR 1.49, 95% CI 1.08-2.06), and delayed pouch creation (HR 0.75, 95% CI 0.57-1.00) were significantly associated with time to development of pouchitis.

CONCLUSION

Although a staged approach to IPAA may have benefits in the surgical management of UC, the timing interval between pouch creation and restoration of continuity did not impact the subsequent development of early pouchitis in this cohort.

Inflammatory bowel disease-related colorectal cancer: Past, present and future perspectives

Inflammatory bowel disease-related colorectal cancer (IBD-CRC) is one of the most serious complications of IBD contributing to significant mortality in this cohort of patients. IBD is often associated with diet and lifestyle-related gut microbial dysbiosis, the interaction of genetic and environmental factors, leading to chronic gut inflammation. According to the “common ground hypothesis”, microbial dysbiosis and intestinal barrier impairment are at the core of the chronic inflammatory process associated with IBD-CRC. Among the many underlying factors known to increase the risk of IBD-CRC, perhaps the most important factor is chronic persistent inflammation. The persistent inflammation in the colon results in increased proliferation of cells necessary for repair but this also increases the risk of dysplastic changes due to chromosomal and microsatellite instability. Multiple pathways have been identified, regulated by many positive and negative factors involved in the development of cancer, which in this case follows the ‘inflammation-dysplasia-carcinoma’ sequence. Strategies to lower this risk are extremely important to reduce morbidity and mortality due to IBD-CRC, among which colonoscopic surveillance is the most widely accepted and implemented modality, forming part of many national and international guidelines. However, the effectiveness of surveillance in IBD has been a topic of much debate in recent years for multiple reasons — cost-benefit to health systems, resource requirements, and also because of studies showing conflicting long-term data. Our review provides a comprehensive overview of past, present, and future perspectives of IBD-CRC. We explore and analyse evidence from studies over decades and current best practices followed globally. In the future directions section, we cover emerging novel endoscopic techniques and artificial intelligence that could play an important role in managing the risk of IBD-CRC.

Pouchitis: Clinical Features, Diagnosis, and Treatment

Procto-colectomy with an ileal pouch anal anastomosis is the procedure of choice for ulcerative colitis patients that require colectomy. Pouchitis is a non-specific inflammation of the ileal reservoir, and the most common, inflammatory and long-term, complication after pouch surgery for ulcerative colitis. The aetiology is still unknown, but many risk factors have been individuated. Pouchitis can be classified based on aetiology, duration, clinical course, and response to antibiotic therapy. Accurate diagnosis and classification is the key factor for an adequate management, and exclusion of secondary causes of pouchitis is pivotal. Most of the patients consistently respond to antibiotic therapy, but management of the subgroup of patients with chronic-antibiotic-resistant-pouchitis is still challenging, being this entity one of the major causes of pouch failure.

Familial adenomatous polyposis and changes in the gut microbiota: New insights into colorectal cancer carcinogenesis

Patients with familial adenomatous polyposis (FAP), an autosomal dominant hereditary colorectal cancer syndrome, have a lifetime risk of developing cancer of nearly 100%. Recent studies have pointed out that the gut microbiota could play a crucial role in the development of colorectal adenomas and the consequent progression to colorectal cancer. Some gut bacteria, such as Fusobacterium nucleatum, Escherichia coli, Clostridium difficile, Peptostreptococcus, and enterotoxigenic Bacteroides fragilis, could be implicated in colorectal carcinogenesis through different mechanisms, including the maintenance of a chronic inflammatory state, production of bioactive tumorigenic metabolites, and DNA damage. Studies using the adenomatous polyposis coliMin/+ mouse model, which resembles FAP in most respects, have shown that specific changes in the intestinal microbial community could influence a multistep progression, the intestinal "adenoma-carcinoma sequence", which involves mucosal barrier injury, low-grade inflammation, activation of the Wnt pathway. Therefore, modulation of gut microbiota might represent a novel therapeutic target for patients with FAP. Administration of probiotics, prebiotics, antibiotics, and nonsteroidal anti-inflammatory drugs could potentially prevent the progression of the adenoma-carcinoma sequence in FAP. The aim of this review was to summarize the best available knowledge on the role of gut microbiota in colorectal carcinogenesis in patients with FAP.

Luteolin alleviates inflammation and modulates gut microbiota in ulcerative colitis rats

Ulcerative colitis (UC) is a chronic inflammatory bowel disease related to intestinal dysbiosis. Luteolin has been reported to reduce inflammation. However, it remains unclear whether luteolin ameliorates UC and regulates gut microbiota. In this study, we investigated the effects of luteolin on colonic structure and inflammation of dextran sulfate sodium (DSS)-induced rats using hematoxylin-eosin staining, immunohistochemistry and enzyme-linked immunosorbent assay and evaluated the effects of luteolin on gut microbiota using 16S rDNA sequencing. We found that luteolin treatment significantly reduced colonic damage, and inhibited colonic inflammation in UC rats, evidenced by the decreased levels of NF-κB, IL-17 and IL-23 in UC rats and the increased level of PPAR-γ. In addition, the 16S rDNA sequencing analysis revealed that luteolin treatment could alter diversity and composition of gut microbiota in UC rats. Lactobacillus, Bacteroides, Roseburia and Butyricicoccus were dominant genera in the luteolin group. Luteolin treatment reduced DSS-induced increased ratios of Lactobacillus and Prevotella_9. Furthermore, KEGG analysis revealed that gut microbiota was mainly related to DNA repair and recombination proteins, ribosome, purine metabolism, peptidases, and pyrimidine metabolism. In conclusion, our results revealed that luteolin could alleviate DSS-induced colitis in rats, and gut microbiota had the potential to serve as promising biomarkers for uncovering the mechanism by which luteolin improved UC.

Gut microbiota and inflammatory bowel disease: The current status and perspectives

Inflammatory bowel disease (IBD) is a chronic immune-mediated disease that affects the gastrointestinal tract. It is argued that environment, microbiome, and immune-mediated factors interact in a genetically susceptible host to trigger IBD. Recently, there has been increased interest in the development, progression, and treatment of IBD because of our understanding of the microbiome. Researchers have proved that some factors can alter the microbiome and the pathogenesis of IBD. As a result, there has been increasing interest in the application of probiotics, prebiotics, antibiotics, fecal microbiota transplantation, and gene manipulation in treating IBD because of the possible curative effect of microbiome-modulating interventions. In this review, we summarize the findings from human and animal studies and discuss the effect of the gut microbiome in treating patients with IBD.

An Update on the Medical Management of Inflammatory Pouch Complications

Total proctocolectomy with ileal pouch-anal anastomosis is the surgical procedure of choice for patients with medically-refractory ulcerative colitis or ulcerative colitis with associated dysplasia. Although most patients after ileal pouch-anal anastomosis experience good functional outcomes, a number of complications may develop. Of the long-term complications, pouchitis is most common. Although most respond to antibiotic treatment, some patients develop chronic pouchitis, leading to substantial morbidity and occasionally pouch failure. In patients with pouchitis who are not responsive to conventional antimicrobial therapy, secondary causes of chronic pouchitis need to be considered, including Crohn's disease of the pouch. In recent years, more literature has become available regarding the medical management of chronic pouchitis and Crohn's disease of the pouch, including the use of newer biologic agents. We herein provide a concise review on inflammatory complications involving the ileal pouch, including a focused approach to diagnosis and medical management.

Prevention and Medical Treatment of Pouchitis In Ulcerative Colitis

Approximately 50% of patients who have undergone IPAA surgery for Ulcerative Colitis (UC) develop at least 1 episode of pouchitis. Patients with pouchitis have a wide range of symptoms, endoscopic and histologic features, disease course, and prognosis. To date, there are no universally accepted diagnostic criteria in terms of endoscopy and histology; though, semi-objective assessments to diagnose pouchitis in patients with ileal pouch- anal anastomosis (IPAA) have been proposed using composite scores such as the Pouchitis Triad, Heidelberg Pouchitis Activity Score and Pouchitis Disease Activity Index (PDAI). In a systematic review that included four randomized trials evaluating five agents for the treatment of acute pouchitis, ciprofloxacin was more effective at inducing remission as compared with metronidazole. Rifaximin was not more effective than placebo, while budesonide enemas and metronidazole were similarly effective for inducing remission of acute pouchitis. Patients with pouchitis relapsing more than three times per year are advised maintenance therapy, and guidelines recommend ciprofloxacin or the probiotic VSL#3. In patients with antibiotic-refractory pouchitis, secondary factors associated with an antibiotic-refractory course should be sought and treated. In this review, we will discuss the prevention and management of pouchitis in Ulcerative Colitis patients.

The microbiome and inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic immune-mediated disease affecting the gastrointestinal tract. IBD consists of 2 subtypes: ulcerative colitis and Crohn disease. IBD is thought to develop as a result of interactions between environmental, microbial, and immune-mediated factors in a genetically susceptible host. Of late, the potential role of the microbiome in the development, progression, and treatment of IBD has been a subject of considerable interest and enquiry. Indeed, studies in human subjects have shown that the gut microbiome is different in patients with IBD compared with that in healthy control subjects. Other evidence in support of a fundamental role for the microbiome in patients with IBD includes identification of mutations in genes involved in microbiome-immune interactions among patients with IBD and epidemiologic observations implicating such microbiota-modulating risk factors as antibiotic use, cigarette smoking, levels of sanitation, and diet in the pathogenesis of IBD. Consequently, there has been much interest in the possible benefits of microbiome-modulating interventions, such as probiotics, prebiotics, antibiotics, fecal microbiota transplantation, and gene manipulation in the treatment of IBD. In this review we will discuss the role of the gut microbiome in patients with IBD; our focus will be on human studies.

Clostridioides Difficile Infection Is a Rare Cause of Infectious Pouchitis

Introduction

The true incidence of Clostridioides difficile infection (CDI) in patients with an ileal pouch is unknown, and there is little published on its associated risk factors.

Objective

We aimed to evaluate the rate and risk factors of CDI in pouch patients.

Methods

This was a retrospective review conducted at a single tertiary care inflammatory bowel disease (IBD) center. All ulcerative colitis or IBD-unspecified (IBD-U) patients who underwent total proctocolectomy with ileal pouch anal anastomosis for medically refractory disease or dysplasia between 2008 and 2017 were identified. Symptomatic patients tested for CDI were included. Demographic, disease, and surgical characteristics were collected. Nonparametric methods were used to compare continuous outcomes, and χ² and Fisher's exact tests were used to compare patients with and without CDI as appropriate.

Results

A total of 154 pouch patients had postoperative C. difficilestool testing for symptoms of fever, urgency, increased stool frequency, hematochezia, incontinence, and abdominal and/or pelvic pain. CDI was diagnosed in 11 (7.1%) patients a median of 139 days (IQR 34-1,170) after the final surgical stage. Ten patients (90.9%) received oral vancomycin for 10 days and 1 patient (9.1%) received oral metronidazole for 2 weeks. Ten patients (90.9%) reported improvement in symptoms at completion of therapy. Nine patients (81.8%) were retested for CDI for recurrent symptoms and found to be negative. No patient had CDI recurrence. There was no significant difference in demographic and surgical characteristics, previous antibiotic or proton pump inhibitor use, or previous hospital admission among the patients with and without CDI.

Conclusions

CDI is a rare cause of infectious pouchitis and treatment with oral vancomycin improves symptoms.

Stachyose modulates gut microbiota and alleviates dextran sulfate sodium-induced acute colitis in mice

BACKGROUND/AIM

Ulcerative colitis (UC) has been implicated to imbalanced enteric flora and reduced microbial diversity. Stachyose is a kind of natural prebiotic which favorably modulate the composition of the gut microbiota. The present study aims to investigate the effects of stachyose on inflammatory levels and gut microbiota of acute colitis mice.

MATERIALS AND METHODS

In this study, the mice were randomly divided into four groups: (1) control group; (2) stachyose group; (3) dextran sulfate sodium (DSS) group; (4) stachyose + DSS group. Hemotoxylin and Eosin (H and E) staining was performed for the distal colon to examine the inflammation and tissue damage. The inflammatory cytokines including IL-6, IL-10, IL-17a, and TNF-α in serum were determined by ELISA assay. The differences in the gut microbiota were analyzed by 16S rDNA gene sequencing.

RESULTS

Histological assay showed that the stachyose treatment significantly reduced the lesions of the colon in DSS-induced colitis. And the upregulated inflammatory cytokines induced by DSS were significantly inhibited by stachyose treatment. Additionally, the sequencing analysis showed that the stachyose changed the gut microbiota composition with a higher level of Akkermansia, as well as selectively increasing some probiotics, including Lactobacillus.

CONCLUSIONS

Our results suggested that stachyose increased beneficial microbiota and bacterial diversity to alleviate acute colitis in mice, which might be a new promising option to UC patients.

DIAGNOSTIC AND MANAGEMENT APPROACH TO POUCHITIS IN INFLAMMATORY BOWEL DISEASE

In patients with ulcerative colitis refractory to medical therapy, total proctocolectomy and posterior ileal-anal pouch anastomosis is the standard surgical therapy. One of the possible complications is pouchitis. Depending on the duration of the symptoms, it can be classified as acute, recurrent, or chronic. The latter, according to the response to therapy, can be defined as antibiotic-dependent or refractory. The treatment of pouchitis is based on the use of antibiotics and probiotics. Thiopurine and biological therapy have been suggested in patients with refractory pouchitis. Special care should be taken in the endoscopic surveillance of these patients, especially if they present risk factors such as dysplasia or previous colorectal cancer, primary sclerosing cholangitis or ulcerative colitis for more than 10 years.

A Comprehensive Approach to Pouch Disorders

Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the surgical procedure of choice for patients with medically refractory ulcerative colitis (UC) or indeterminate colitis, UC with colonic dysplasia or neoplasia, and familial adenomatous polyposis. In general, patients experience good function outcomes and quality of life with an IPAA. Although pouchitis is the most well-recognized and frequent complication after IPAA, a number of additional inflammatory, postsurgical, structural, neoplastic, and functional complications may occur, resulting in pouch dysfunction. We herein provide a comprehensive review of pouch function and an approach to diagnosis and management of pouch complications.

Current Evidence for the Management of Inflammatory Bowel Diseases Using Fecal Microbiota Transplantation

PURPOSE OF REVIEW

Fecal microbiota transplantation (FMT) has been investigated as a potential treatment for inflammatory bowel disease (IBD). This review examines current evidence around the efficacy and safety of FMT for patients with IBD.

RECENT FINDINGS

Randomized controlled trials (RCTs) and meta-analyses have suggested that FMT may facilitate clinical and endoscopic remission in patients with active ulcerative colitis (UC). Although the evidence for FMT in Crohn's disease (CD) is more limited, positive outcomes have been observed in small cohort studies. Most adverse events (AEs) were mild and included transient gastrointestinal symptoms. Serious adverse events (SAEs) did not differ significantly between the FMT and control groups, and a marginal increased rate of IBD flares following FMT was observed. Microbiota analysis following FMT showed increased intestinal bacterial diversity and a shift towards the donor microbial profile in recipients' stools. FMT for patients with IBD is promising as RCTs have shown the benefit of FMT for UC, although the efficacy of FMT for CD is less clear. Further large and well-designed trials are necessary to resolve critical issues such as the donor selection, the ideal route of administration, duration, frequency of FMT, and the long-term sustained efficacy and safety.

Nonrelaxing Pelvic Floor Dysfunction Is an Underestimated Complication of Ileal Pouch-Anal Anastomosis

BACKGROUND & AIMS

Nonrelaxing pelvic floor dysfunction (N-RPFD), or dyssynergic defecation, is the paradoxical contraction and/or impaired relaxation of pelvic floor and anal muscles during defecation. Few studies have evaluated this disorder in patients with an ileal pouch-anal anastomosis (IPAA). We investigated the frequency of N-RPFD in patients with and without chronic pouchitis following IPAA and the effectiveness of biofeedback therapy within this population.

METHODS

We conducted a retrospective study of all patients with an IPAA who underwent anorectal manometry between January 2000 and March 2015 (n = 111). N-RPFD was diagnosed in patients with symptoms consistent with a pouch evacuation disorder and 1 or more of the following abnormal tests: anorectal manometry, balloon expulsion test, barium or magnetic resonance defecography, or external anal sphincter electromyography. Patients who completed biofeedback therapy were identified and assessed to determine symptomatic response.

RESULTS

Of the 111 patients evaluated, 83 (74.8%) met criteria for N-RPFD. A significantly higher proportion of patients with chronic pouchitis were diagnosed with N-RPFD than patients without chronic pouchitis (83.3% vs 62.2%, respectively; P = .012). Most patients diagnosed with N-RPFD had abnormal results from the balloon expulsion test (78.3%); 53.0% of patients diagnosed with N-RPFD had abnormal findings from external anal sphincter electromyography, 25.3% had abnormal defecography findings, and 20.5% had abnormal findings from anorectal manometry. Twenty-two patients completed biofeedback therapy: 15 patients (68.2%) had mild-moderate improvement and 5 patients (22.7%) had significant improvement of symptoms.

CONCLUSIONS

N-RPFD occurs in almost 75% of patients with an IPAA, especially in patients with chronic pouchitis. Biofeedback seems to be an effective therapy for patients with an IPAA and N-RPFD, but further studies are needed for validation.

Lactobacillus acidophilus alleviates pouchitis after ileal pouch-anal anastomosis in rats

AIM

To assess the therapeutic potential of Lactobacillus acidophilus (LA) for the treatment of pouchitis in a rat model.

METHODS

Sprague Dawley rats underwent proctocolectomy and ileal pouch-anal anastomosis followed by administration of dextran sulfate sodium (DSS) to induce pouchitis. Rats with pouchitis were randomly divided into three groups: no intervention (NI), normal saline (NS, 3 mL/d normal saline for 7 d), and LA (3 mL/d LA at 1× 10¹⁰ colony-forming units for 7 d). General body condition was recorded and pouch specimens were obtained for histological examination. mRNA expression levels of interleukin (IL)-1β, IL-6, IL-10, and tumor necrosis factor-α were determined by RT-PCR. Zonula occludens protein 1 (ZO-1) levels were measured by immunohistochemistry.

RESULTS

LA reduced weight loss associated with pouchitis (P < 0.05) and improved the symptoms of pouchitis in rats. Compared with the NI and NS groups, rats in the LA group showed earlier disappearance of hematochezia (6.17 ± 0.75, 6.50 ± 0.55, 3.17 ± 0.75, P < 0.05) and higher fecal scores (2.67 ± 0.48, 2.50 ± 0.51, 4.42 ± 0.50, respectively, P < 0.05). Histological scores were also lower in the LA group compared with the other two groups (7.17 ± 0.98, 8.00 ± 0.89, 4.00 ± 0.89, respectively, P < 0.05). mRNA expression levels of IL-1β, IL-6, and tumor necrosis factor-α were significantly reduced, while IL-10 mRNA levels were significantly increased in the LA group (P < 0.05, respectively). ZO-1 protein levels were also significantly increased after administration of LA (P < 0.05).

CONCLUSION

LA alleviates pouchitis induced by DSS after ileal pouch-anal anastomosis by decreasing pro-inflammatory factors and increasing anti-inflammatory factors, and restoring ZO-1 expression in the mucosa.

Role of intestinal microbiota in pathogenesis of inflammatory bowel disease

Inflammatory bowel disease (IBD) is characterized by chronic non-specific inflammation of the intestinal tract, and it easily relapses. The pathogenesis of IBD is not fully clear up to now. Intestinal microbiota has been confirmed to play an important role in the development and activation of the intestinal immune system. The changes of intestinal microbiota may induce or aggravate IBD, and regulating intestinal microbiota may have positive effects on the treatment of IBD. This article will discuss the relationship between intestinal microbiota and IBD.

Role of intestinal flora imbalance in pathogenesis of pouchitis

OBJECTIVE

To discuss the role of intestinal flora imbalance in the pathogenesis of pouchitis.

METHODS

The pouchitis rat model was established and the faeces sample and the mucous membrane sample were collected regularly, in which the bacterial nucleic acids were extracted for quantitative analysis of the intestinal flora in the samples through using the real-time quantitative PCR technique and high energy sequencing technology.

RESULTS

The disorder phenomenon of the intestinal flora appeared at the 7th day of the experiment, and the pouchitis was presented at the 21st day of the experiment. At the 31st day of the experiment, compared to control group and non-pouchitis group, the quantity of Bifidobacterium and the Lactobacillus of the pouchitis model rats in the mucous membrane sample and the faeces sample were significantly decreased (P < 0.05), and the Bacteroidetes, Faecalibacterium prausnitzii and XIV Clostridium leptum subgroup in the mucous membrane of pouchitis were significantly decreased (P < 0.05). The IV Clostridium coccoides group was the main flora in the mucous membrane of pouchitis, the bacterial diversity of non-pouchitis group and control group was significantly higher than that of the pouchitis group (P < 0.05).

CONCLUSIONS

The intestinal flora imbalance is one of the factors that cause the incidence of the pouchitis; this study provides a clue of the pathogenesis and treatment direction of the intestinal inflammatory disease.

The therapeutic potential of antibiotics and probiotics in the treatment of pouchitis

Pouchitis is the most frequent long-term complication of pouch surgery for ulcerative colitis. There is consistent evidence on the implication of bacterial flora in the pathogenesis of pouchitis, and there is evidence for a therapeutic role of antibiotics and probiotics in therapy of this disease. Antibiotics, particularly ciprofloxacin and metronidazole, are the mainstay of treatment for acute pouchitis. In chronic refractory pouchitis, after having excluded other diagnoses (infections, Crohn's disease of the pouch, ischemia and irritable pouch), antibiotic combination therapy is the treatment of choice. The highly concentrated probiotic mixture VSL#3 has been shown to be effective in prevention of pouchitis onset and in maintaining antibiotic-induced remission.

Microbiota in Inflammatory Bowel Disease Pathogenesis and Therapy: Is It All About Diet?

Inflammatory bowel disease (IBD), including ulcerative colitis, Crohn's disease, and unclassified IBD, continues to cause significant morbidity. While its incidence is increasing, no clear etiology and no cure have yet been discovered. Recent findings suggest that IBD may have a multifactorial etiology, where complex interactions between genetics, epigenetics, environmental factors (including diet but also infections, antibiotics, and sanitation), and host immune system lead to abnormal immune responses and chronic inflammation. Over the past years, the role of altered gut microbiota (in both composition and function) in IBD pathogenesis has emerged as an outstanding area of interest. According to new findings, gut dysbiosis may appear as a key element in initiation of inflammation in IBD and its complications. Moreover, complex metagenomic studies provide possibilities to distinguish between IBD types and appreciate severity and prognosis of the disease, as well as response to therapy. This review provides an updated knowledge of recent findings linking altered bacterial composition and functions, viruses, and fungi to IBD pathogenesis. It also highlights the complex genetic, epigenetic, immune, and microbial interactions in relation to environmental factors (including diet). We overview the actual options to manipulate the altered microbiota, such as modified diet, probiotics, prebiotics, synbiotics, antibiotics, and fecal transplantation. Future possible therapies are also included. Targeting altered microbiota could be the next therapeutic personalized approach, but more research and well-designed comparative prospective studies are required to formulate adequate directions for prevention and therapy.

Frequency, Clinical Features and Factors Associated with Pouchitis after Proctocolectomy with Ileo-Pouch-Anal Anastomosis in Patients with Ulcerative Colitis: A Latin-American Country Retrospective-Cohort Study

BACKGROUND

Pouchitis is the most common complication of proctocolectomy with ileo-pouch-anal anastomosis (IPAA) for ulcerative colitis (UC). No previous study in Mexico has evaluated this issue; our aim was to evaluate its frequency, clinical characteristics and factors associated with its presence in Mexican patients with UC and IPAA.

METHODS

Retrospective-cohort study including 70 patients with histopathological diagnosis of UC and IPAA between 1983 and 2014 from inflammatory bowel disease clinic of a tertiary care center. The statistical analysis used descriptive statistics, chi-square and Fisher's exact test for categorical variables and Student's t test for numeric variables. Univariate analysis was performed to identify the factors associated.

RESULTS

Patients presenting with pouchitis accounted for 48.6%. From the 34 cases, 12 (35.3%) had inactive pouchitis; 7 (20.6%) active acute pouchitis; 15 (44.1%) chronic active pouchitis. On average, pouchitis occurred 5.37 years after IPPA. Factors probably associated with its occurrence were the presence of autoimmune concomitant diseases (ACDs; p = 0.06, OR 4.40, 95% CI 0.84-22.9) and extra-intestinal manifestations (EIMs; p = 0.05, OR 2.53, 95% CI 0.96-6.64), which was also probably associated with chronic active pouchitis (p = 0.06, OR 0.31, 95% CI 0.07-1.31).

CONCLUSIONS

The frequency of pouchitis is high in Mexican UC patients after IPAA. ACDs and EIMs were probably associated with its development.

Surgical Principles in the Treatment of Ulcerative Colitis

Background

The primary treatment of ulcerative colitis (UC) is conservative; surgical intervention is carried out in the case of therapy-refractory situation, imminent or malignant transformation, or complications. Surgery for UC should be indicated by interdisciplinary means. Despite the development of drug therapy – in particular the introduction of biologics -, a surgical intervention becomes necessary in a relevant proportion of patients with UC throughout lifetime.

Methods

A selective literature search was conducted, taking into account the current studies, reviews, meta-analyses, and guidelines. PubMed served as a database. The present work gives an overview of the surgical options, outcome as well as peri- and postoperative management for patients with UC.

Results

Approximately 20% of patients with UC will require surgery during the course of their disease. The rate of colectomy after a disease duration of 10 years is at approximately 16%. Unlike Crohn's disease, UC is principally surgically curable since it is naturally limited to the colon and rectum. Restorative proctocolectomy with an ileal pouch-anal anastomosis represents the surgical treatment of choice. Large studies show a postoperative complication rate of around 30% and a low mortality of 0.1% for this procedure. Chronic pouchitis is one of the main factors limiting the surgical success of curing UC. Despite a high postoperative complication rate, there is a long-term pouch success rate of >90% after 10 and 20 years of follow-up.

Conclusion

A close cooperation between the various disciplines in the pre- and postoperative setting is essential for an optimal outcome of patients with UC. Despite a 30% rate of early postoperative complications, normal quality of life can ultimately be reached in more than 90% of patients in experienced centers.

Inflammatory pouch disease: The spectrum of pouchitis

Restorative proctocolectomy with ileal-pouch anal anastomosis (IPAA) is the operation of choice for medically refractory ulcerative colitis (UC), for UC with dysplasia, and for familial adenomatous polyposis (FAP). IPAA can be a treatment option for selected patients with Crohn’s colitis without perianal and/or small bowel disease. The term “pouchitis” refers to nonspecific inflammation of the pouch and is a common complication in patients with IPAA; it occurs more often in UC patients than in FAP patients. This suggests that the pathogenetic background of UC may contribute significantly to the development of pouchitis. The symptoms of pouchitis are many, and can include increased bowel frequency, urgency, tenesmus, incontinence, nocturnal seepage, rectal bleeding, abdominal cramps, and pelvic discomfort. The diagnosis of pouchitis is based on the presence of symptoms together with endoscopic and histological evidence of inflammation of the pouch. However, “pouchitis” is a general term representing a wide spectrum of diseases and conditions, which can emerge in the pouch. Based on the etiology we can sub-divide pouchitis into 2 groups: idiopathic and secondary. In idiopathic pouchitis the etiology and pathogenesis are still unclear, while in secondary pouchitis there is an association with a specific causative or pathogenetic factor. Secondary pouchitis can occur in up to 30% of cases and can be classified as infectious, ischemic, non-steroidal anti-inflammatory drugs-induced, collagenous, autoimmune-associated, or Crohn’s disease. Sometimes, cuffitis or irritable pouch syndrome can be misdiagnosed as pouchitis. Furthermore, idiopathic pouchitis itself can be sub-classified into types based on the clinical pattern, presentation, and responsiveness to antibiotic treatment. Treatment differs among the various forms of pouchitis. Therefore, it is important to establish the correct diagnosis in order to select the appropriate treatment and further management. In this editorial, we present the spectrum of pouchitis and the specific features related to the diagnosis and treatment of the various forms.