Bacteriology in the etiopathogenesis of pouchitis

Surgical Options for Appropriate Length of J-Pouch Construction for Better Outcomes and Long-term Quality of Life in Patients with Ulcerative Colitis after Ileal Pouch-Anal Anastomosis

Background/Aims

Total proctocolectomy with ileal pouch-anal anastomosis (IPAA) is widely accepted as a radical surgery for refractory ulcerative colitis (UC). Definite results on the appropriate pouch length for an evaluation of the risk-to-benefit ratio regarding technical complications and long-term quality of life (QOL) are still scarce.

Methods

Data on UC patients who underwent IPAA from 2008 to 2022 in four well-established pouch centers affiliated to China UC Pouch Center Union were collected.

Results

A total of 208 patients with a median follow-up time of 6.0 years (interquartile range, 2.3 to 9.0 years) were enrolled. The median lengths of the patients' short and long pouches were 14.0 cm (interquartile range, 14.0 to 15.0 cm) and 22.0 cm (interquartile range, 20.0 to 24.0 cm), respectively. Patients with a short J pouch configuration were less likely to achieve significantly improved long-term QOL (p=0.015) and were prone to develop late postoperative complications (p=0.042), such as increased defecation frequency (p=0.003) and pouchitis (p=0.035). A short ileal pouch was an independent risk factor for the development of late postoperative complications (odds ratio, 3.100; 95% confidence interval, 1.519 to 6.329; p=0.002) and impaired longterm QOL improvement (odds ratio, 2.221; 95% confidence interval, 1.218 to 4.050, p=0.009).

Conclusions

The length of the J pouch was associated with the improvement in long-term QOL and the development of late post-IPAA complications. A long J pouch configuration could be a considerable surgical option for pouch construction.

Pouchitis Is Associated with Paneth Cell Dysfunction and Ameliorated by Exogenous Lysosome in a Rat Model Undergoing Ileal Pouch Anal Anastomosis

BACKGROUND

Pouchitis is a common complication of restorative proctocolectomy and ileal pouch anal anastomosis (IPAA) for ulcerative colitis (UC), significantly affecting the postoperative quality of life. Paneth cells play an important role in the maintenance of gut homeostasis. This study aimed to investigate the role of Paneth cells in the pathogenesis of pouchitis.

METHOD

Endoscopic biopsies from the pouch body and terminal ileum of UC patients undergoing IPAA with or without pouchitis were obtained to analyze Paneth cell function. Acute pouchitis was induced with 5% dextran sulfate sodium (DSS) for seven consecutive days in a rat model of IPAA. The Paneth cell morphology was examined by immunofluorescence and electron microscopy. The effect of exogenous lysozyme supplementation on pouchitis was also investigated. The fecal microbiota profile after DSS and lysozyme treatment was determined by 16s rRNA ITS2 sequence analysis.

RESULT

Abnormal mucosal lysozyme expression was observed in patients with pouchitis. The rat model of pouchitis showed increased pouch inflammation, increased CD3+ and CD45+ T cell infiltration, and decreased tight junction proteins, including ZO-1 and Occludin. There is a significant deficiency of Paneth cell-derived lysozyme granules in the rat model of pouchitis. Supplementation with exogenous lysozyme significantly ameliorated pouchitis, lowering the levels of inflammatory cytokines such as TNF-α and IL-6 in the pouch tissue. 16s rRNA analysis revealed a higher Lachnospiraceae level after lysosome treatment.

CONCLUSIONS

Paneth cell dysfunction is prominent in patients and rat models of pouchitis and may be one of its causes. The decrease in Lachnospiraceae, a characteristic of dysbiosis in pouchitis, could be reserved by lysosome treatment. Lysozyme supplementation shows promise as a novel treatment strategy for pouchitis.

Fecal Microbiota Transplantation for the Treatment of Inflammatory Bowel Disease: An Update

Fecal microbiota transplantation (FMT) has successfully been applied for the treatment of recurrent Clostridioides difficile infection (CDI), which has led to studies on its application to other gastrointestinal diseases and extraintestinal diseases associated with gut microbiota dysbiosis. Recently, the results of FMT for patients with inflammatory bowel disease (IBD) have been encouraging. However, studies have not fully clarified the clinical application of this emerging therapy. Here, we aimed to review the current knowledge in this fast-growing field and characterize the effectiveness, safety and mechanisms of FMT for the treatment of IBD patients.

Dysbiosis-Induced Secondary Bile Acid Deficiency Promotes Intestinal Inflammation

Secondary bile acids (SBAs) are derived from primary bile acids (PBAs) in a process reliant on biosynthetic capabilities possessed by few microbes. To evaluate the role of BAs in intestinal inflammation, we performed metabolomic, microbiome, metagenomic, and transcriptomic profiling of stool from ileal pouches (surgically created resevoirs) in colectomy-treated patients with ulcerative colitis (UC) versus controls (familial adenomatous polyposis [FAP]). We show that relative to FAP, UC pouches have reduced levels of lithocholic acid and deoxycholic acid (normally the most abundant gut SBAs), genes required to convert PBAs to SBAs, and Ruminococcaceae (one of few taxa known to include SBA-producing bacteria). In three murine colitis models, SBA supplementation reduces intestinal inflammation. This anti-inflammatory effect is in part dependent on the TGR5 bile acid receptor. These data suggest that dysbiosis induces SBA deficiency in inflammatory-prone UC patients, which promotes a pro-inflammatory state within the intestine that may be treated by SBA restoration.

Recommendations of the Spanish Working Group on Crohn's Disease and Ulcerative Colitis (GETECCU) on pouchitis in ulcerative colitis. Part 1: Epidemiology, diagnosis and prognosis

Pouchitis is a common complication in ulcerative colitis patients after total proctocolectomy. This is an unspecific inflammation of the ileo-anal pouch, the aetiology of which is not fully known. This inflammation induces the onset of symptoms such as urgency, diarrhoea, rectal bleeding and abdominal pain. Many patients suffering from pouchitis have a lower quality of life. In addition to symptoms, an endoscopy with biopsies is mandatory in order to establish a definite diagnosis. The recommended index to assess its activity is the Pouchitis Disease Activity Index (PDAI), but its modified version (PDAIm) can be used in clinical practice. In accordance with the duration of symptoms, pouchitis can be classified as acute (<4 weeks) or chronic (>4 weeks), and, regarding its course, pouchitis can be infrequent (<4 episodes per year), recurrent (>4 episodes per year) or continuous.

Insights into the role of fecal microbiota transplantation for the treatment of inflammatory bowel disease

Fecal microbiota transplantation (FMT) has changed the treatment landscape of Clostridium difficile infection (CDI). Emerging evidence has shown that FMT can also be an effective and safe treatment strategy in CDI with underlying inflammatory bowel disease (IBD). Recently, randomized controlled trials of FMT in ulcerative colitis support its expanding role in restoring gut homeostasis in this disease. However, heterogeneous study designs leave several questions yet to be answered, including how to best position this novel therapy in the treatment approach of Crohn's disease and pouchitis. Additional studies are needed to validate whether FMT can assume a complementary role in the standard treatment of IBD.

Management of Pouchitis and Other Common Complications of the Pouch

Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) has become the preferred surgical treatment for refractory or complicated ulcerative colitis (UC) and familial adenomatous polyposis (FAP). Pouchitis is the most common complication of this procedure and can occur in about 50% of patients. Treatment of pouchitis depends on the phenotype of disease. Pouchitis can be classified as acute, chronic/refractory, or secondary pouchitis, which includes pouchitis occurring due to Crohn's disease (CD). CD of the pouch is becoming an increasingly recognized problem, and management is challenging. This article reviews the literature and offers treatment recommendations regarding management of pouchitis and CD of the pouch.

Systematic review: ileoanal pouch microbiota in health and disease

BACKGROUND

The resident gut microbiota is essential for physiological processes; the disturbance of its balance is linked to intestinal inflammation. The ileoanal pouch is a model for the study of intestinal inflammation, as inflammation of the pouch is common and mostly develops within 12 months following ileostomy closure. This allows the longitudinal study of the microbiota, giving insight into the microbiota changes during transition from a normal to an inflamed pouch.

AIM

To explore the literature on the microbiota of the ileoanal pouch in health and disease.

METHODS

A systematic computer search of the on-line bibliographic databases MEDLINE and EMBASE was performed between 1966 and February 2017. Randomised controlled trials, cohort studies and observational studies were included. Studies were included if they reported microbiota analysis on faecal samples or tissue from the ileoanal pouch.

RESULTS

Twenty-six papers were eligible. Following ileostomy closure, anaerobic bacteria are the abundant species in the ileoanal pouch with presence of a diverse microbiota key to maintaining a healthy ileoanal pouch. Acute pouchitis is associated with an increase in Clostridia species, while chronic pouchitis is associated with an increase in Staphylococcus aureus. In the treatment of pouchitis, a decrease in Clostridia species appears to be associated with treatment response.

CONCLUSION

The microbiota plays an important role in both the inflamed and the healthy ileoanal pouch. A direct causal relationship between individual microbiota changes and inflammation has not yet been established, but manipulation of the ileoanal pouch microbiota may be a novel therapeutic avenue to explore.

Specific members of the predominant gut microbiota predict pouchitis following colectomy and IPAA in UC

OBJECTIVE

Pouchitis is the most common complication after colectomy with ileal pouch-anal anastomosis (IPAA) for UC and the risk is the highest within the 1st year after surgery. The pathogenesis is not completely understood but clinical response to antibiotics suggests a role for gut microbiota. We hypothesised that the risk for pouchitis can be predicted based on the faecal microbial composition before colectomy.

DESIGN

Faecal samples from 21 patients with UC undergoing IPAA were prospectively collected before colectomy and at predefined clinical visits at 1 month, 3 months, 6 months and 12 months after IPAA. The predominant microbiota was analysed using community profiling with denaturing gradient gel electrophoresis followed by quantitative real-time PCR validation.

RESULTS

Cluster analysis before colectomy distinguished patients with pouchitis from those with normal pouch during the 1st year of follow-up. In patients developing pouchitis, an increase of Ruminococcus gnavus (p<0.001), Bacteroides vulgatus (p=0.043), Clostridium perfringens (p=0.011) and a reduction of two Lachnospiraceae genera (Blautia (p=0.04), Roseburia (p=0.008)) was observed. A score combining these five bacterial risk factors was calculated and presence of at least two risk factors showed a sensitivity and specificity of 100% and 63.6%, respectively.

CONCLUSIONS

Presence of R. gnavus, B. vulgatus and C. perfringens and absence of Blautia and Roseburia in faecal samples of patients with UC before surgery is associated with a higher risk of pouchitis after IPAA. Our findings suggest new predictive and therapeutic strategies in patients undergoing colectomy with IPAA.

Anti-Outer membrane protein C and anti-glycoprotein 2 antibodies in inflammatory bowel disease and their association with complicated forms of Crohn's disease

Background

Precise diagnostics of inflammatory bowel disease (IBD) and identification of potentially more aggressive phenotypes of Crohn’s disease (CD) is urgently needed. The aim of our prospective study was to assess the relationship between serum anti-OmpC IgA (Outer membrane protein C), anti-GP2 (anti-glycoprotein 2) IgG and anti-GP2 IgA antibodies with IBD and their association with complicated forms of CD.

Methods

The study included 86 patients with CD, 25 patients with UC and 45 controls, blood donors. In CD group, 24/86 (28%) had B1 phenotype, 20/86 (23%) B2, 13/86 (15%) B3 and 29/86 (34%) B2 + B3. L1 involvement was present in 13/86 (15%), L2 in 13/86 (15%), L3 in 60/86 (70%). Serum anti-OmpC IgA, anti-GP2 IgG and IgA antibodies were investigated by means of ELISA. The data obtained were tested statistically by means of descriptive statistics, non-paired t-test, Mann-Whitney rank sum test, Spearman rank order correlation and Pearson product moment correlation using SigmaStat software.

Results

Anti-OmpC IgA were noted to be significantly higher in CD (median 32.6, inter-quartile range (IQR) 18.9-60.7) compared to the controls (median 18.3, IQR 11.1-23.1), p < 0.001. Anti-GP2 IgG were significantly higher in CD (median 13.9, IQR 8.6-25.6) compared to the controls (median 8.0, IQR 4.7-10.8), p < 0.001. Anti-GP2 IgA were significantly higher in CD (median 20.1, IQR 9.1-40.4) compared to the controls (median 9.8, IQR 5.6-16.9), p < 0.001. Significant difference was found in anti-OmpC IgA between UC (median 26.2, IQR 20.2-36.4) and the controls (median 18.3, IQR 11.1-23.1), p < 0.001. In CD anti-OmpC IgA were significantly higher in B2 compared to B1: p = 0.041 and in B2 + B3 compared to B1: p = 0.036. Anti-GP2 IgA were significantly higher in B2 + B3 compared to B1: p = 0.009 and in B3 compared to B1: p = 0.029. In CD there was a significant difference in anti-OmpC IgA between patients with surgery and without surgery, p = 0.005.

Conclusions

We have confirmed association between anti-OmpC IgA and IBD (CD and UC) and an association between anti-GP2 (IgG and IgA) and CD. Patients with complicated forms of CD have significantly higher levels of anti-OmpC IgA and anti-GP2 IgA.

Managing intractable proctitis and the problematic pouch

Proctitis accounts for a significant proportion of cases of ulcerative colitis (UC), and some patients subsequently develop more extensive disease. However, most patients continue to have limited inflammation, although the changes in the distal colon and rectum can occasionally be severe, and symptoms of increased frequency, rectal bleeding and urgency can be as disabling as they are for patients with more extensive colitis. Furthermore, although symptoms are typically well controlled with standard medications, medically refractory proctitis poses particular problems. Patients generally are not systemically unwell, and there is no added fear of cancer. Therefore, the prospect of colectomy for such limited disease is resisted by patients, physicians and surgeons alike. Unusual therapies, often delivered locally by enema or suppository, have been tested in small case series without definitive outcomes. The pathogenesis of such limited, yet intractable inflammation remains unclear, and the differential diagnosis should be carefully reviewed to ensure that local disease, whether it is infectious, vascular, or a result of injury or degeneration, is not overlooked. Ileo-anal pouch formation is the surgery of choice for about 20% of patients with UC who undergo colectomy. In the majority of cases, this surgery results in an acceptable quality of life and freedom from a stoma. However, in a sizeable minority of cases, pouch dysfunction can cause intractable problems. The causes of pouch dysfunction are varied and must all be considered carefully, particularly in refractory cases. Pouchitis is a common issue and is usually transient and easily treated. However, refractory and chronic pouchitis can be challenging. Ischaemia, injury, infection and Crohn's disease can all cause refractory pouch dysfunction. In a minority of cases, there appears to be no apparent organic pathology, and the presumptive diagnosis is that of a functional pouch disorder. Although it is much rarer, neoplastic changes in the pouch must also be considered, and the risk managed appropriately. The management of both intractable proctitis and the problematic pouch is made more challenging by the wide differential diagnosis that must be considered and by the paucity of high-quality clinical trials to support any one therapy. Key strategies to overcoming these limitations include methodical and systematic investigation and review, and a willingness to tailor therapy to the individual patient. Clinical trials of new treatments should be supported, and data from the experience with small cohorts of patients should be meticulously collected, critically analysed and widely disseminated.

What we know now: pouch surgery 40 years on

For many patients, ileal pouch-anal anastomosis (also called ileo-anal pouch surgery) not only eradicates disease but also preserves the anal sphincter, enabling the patient to defecate in the normal way. Pouch surgery is approaching 40 years and within this time has become the 'gold standard' in surgical management for ulcerative colitis and familial adeomatous polyposis. Much of the research over the years has explored surgical techniques and pouch function, failure and satisfaction, as well as long-term follow-up; however, some pouch problems continue to be a mystery. This short article aims to bring us up to date with what we know now that might have been beneficial to know then.

Should we recycle more than our plastic?

For many patients, ileal pouch-anal anastomosis (also called ileoanal pouch surgery) not only eradicates disease but also preserves the anal sphincter, enabling the patient to defecate in the normal way. Pouch surgery is approaching 40 years and within this time has become the ‘gold standard’ in surgical management for ulcerative colitis and familial adeomatous polyposis. Much of the research over the years has explored surgical techniques and pouch function, failure and satisfaction, as well as long-term follow-up; however, some pouch problems continue to be a mystery. This short article aims to bring us up to date with what we know now that might have been beneficial to know then.