Local short-chain fatty acids supplementation without beneficial effect on inflammation in excluded rectum

Diversion proctocolitis and the problem of the forgotten rectum in inflammatory bowel diseases: A systematic review

Background and aims

Diversion proctocolitis (DP) is a non‐specific mucosal inflammation arising in the defunctionalized colon and/or rectum following faecal diversion (colostomy, ileostomy). Differential diagnosis of DP from the underlying disease in patients with inflammatory bowel diseases (IBD) is often unclear. As a result, it might be difficult to undertake any specific treatment. We aimed to systematically review the literature evidence on DP in IBD patients.

Methods

For this qualitative systematic review, we searched PubMed, EMBASE and Scopus to identify all studies published until July 2021 including IBD patients affected by DP.

Results

Overall, 37 papers published between 1982 and 2021 were included. A total of 1.211 IBD patients were included: 613 UC (50.6%), 524 CD (43.3%), 66 IBD‐unclassified (IBD‐U) (5.4%), 8 unspecified patients (0.7%). Most patients with DP are asymptomatic, although inflammation is detectable in almost all patients with a rectal stump. Reduced short‐chain fatty acids and an altered microbiome, may trigger mucosal inflammation and have been proposed as causing factors. An increased risk of developing cancer on DP has been reported in patients with a history of previous dysplasia/cancer.

Conclusions

The etiopathogenesis of DP is still unknown. The efficacy of mesalamine, corticosteroids or short‐chain fatty acids has not been proven by randomized trials yet. Since the incidence of cancer of the rectal stump can reach 4.5 per 1.000 diverted patients‐year, IBD patients undergoing subtotal colectomy with end‐ileostomy should undergo close endoscopic surveillance, being eventually counseled for surgery with or without the restoration of the intestinal continuity.

Serological Biomarkers and Diversion Colitis: Changes after Stimulation with Probiotics

Diversion colitis is a non-specific inflammation of a defunctionalised segment of the colon after a temporary stoma has been performed. This inflammation is associated with an alteration of certain inflammatory serum markers. The aims of this study were, firstly, to evaluate the modification of inflammatory biomarkers after stimulation with probiotics prior to closure of the protective ileostomy. Secondly, to identify if a relationship could be established between the severity of diversion colitis and the alteration of inflammatory biomarkers in the blood. A prospective, randomized, double-blind, controlled study was conducted. Patients who underwent surgery for colorectal carcinoma with protective ileostomy between January 2017 and December 2018 were included, pending reconstructive surgery and with diversion colitis as diagnosis. The sample was randomly divided into a group stimulated with probiotics (SG) (n = 34) and a control group (CG) (n = 35). Histological and endoscopic changes were evaluated after stimulation, after restorative surgery and during the short-term follow-up after surgery, including the correlation with pro-inflammatory biomarkers in blood. As main findings, a significant decrease in C-reactive protein (CRP), Neutrophil/lymphocyte ratio (NLR ratio), and monocyte/lymphocyte ratio (LMR ratio) was observed in the SG versus the CG with a p < 0.001. A significant increase in transferrin values and in the platelet/lymphocyte ratio (PLR) was observed in the SG versus CG after stimulation with probiotics with a p < 0.001. A normalisation of CRP and transferrin levels was observed in the third month of follow-up after closure ileostomy, and NLR, LMR and PLR ratios were equal in both groups. Decreased modified Glasgow prognostic score was found in SG compared to CG after probiotic stimulation (p < 0.001). The endoscopic and histological severity of diversion colitis is associated with a greater alteration of blood inflammatory biomarkers. The stimulation with probiotics prior to reconstructive surgery promotes an early normalization of these parameters.

Diversion Colitis: Macro and Microscopic Findings after Probiotics Stimulation

Simple Summary

The observations presented in this study conclude that the preoperative stimulation with probiotics of the efferent loop through the dysfunctional bowel, to allow the slow infusion, can have a reducing effect on the endoscopic and histopathological alterations of diversion colitis. This procedure may be an alternative treatment to resolve the inflammation in patients where the surgical option is not feasible or available.

Abstract

The use of a loop ileostomy as the defunctioning procedure of choice to protect a distal colonic anastomosis causes histological and endoscopic changes in the intestinal mucosal architecture, which have been related to chronic inflammation and changes in the microflora that consequently impact the intestinal structure and function following fecal stream diversion. The aim of this study was to evaluate the histological and endoscopic changes on the colonic mucosa in patients with diversion colitis after stimulation of the efferent loop with probiotics prior to closure of the protective ileostomy. A prospective, randomized, double-blind, controlled study was designed. All patients who underwent surgery for colorectal carcinoma with protective ileostomy between January 2017 and December 2018 were included. These patients were pending reconstructive surgery and were diagnosed with endoscopic and histological diversion colitis. Divided into two groups, a group stimulated with probiotics (SG) and a control group (CG). 34 cases and 35 controls were included in the study. Histological and endoscopic changes were evaluated after stimulation, after restorative surgery and during the short-term follow-up after surgery. A decrease in endoscopic pathological findings (mucosal friability, mucous erosions, polyps, edema, erythema and stenosis) and in histological findings (follicular hyperplasia, eosinophils, cryptic abscesses, lymphocyte infiltration, plasma cell infiltration and architecture distortion) was observed in SG. These results were statistically significant with a p < 0.001. The stimulation of the efferent loop of the ileostomy in patients with diversion colitis produced a decrease of the endoscopic and histological severity of colitis in the short term.

Subtotal colectomy in ulcerative colitis—long term considerations for the rectal stump

BACKGROUND

The initial operation of choice in many patients presenting as an emergency with ulcerative colitis is a subtotal colectomy with end ileostomy. A percentage of patients do not proceed to completion proctectomy with ileal pouch anal anastomosis.

AIM

To review the existing literature in relation to the significant long-term complic-ations associated with the rectal stump, to provide an overview of options for the surgical management of remnant rectum and anal canal and to form a consolidated guideline on endoscopic screening recommendations in this cohort.

METHODS

A systematic review was carried out in accordance with PRISMA guidelines for papers containing recommendations for endoscopy surveillance in rectal remnants in ulcerative colitis. A secondary narrative review was carried out exploring the medical and surgical management options for the retained rectum.

RESULTS

For rectal stump surveillance guidelines, 20% recommended an interval of 6 mo to a year, 50% recommended yearly surveillance 10% recommended 2 yearly surveillance and the remaining 30% recommended risk stratification of patients and different screening intervals based on this. All studies agreed surveillance should be carried out via endoscopy and biopsy. Increased vigilance is needed in endoscopy in these patients. Literature review revealed a number of options for surgical management of the remnant rectum.

CONCLUSION

The retained rectal stump needs to be surveyed endoscopically according to risk stratification. Great care must be taken to avoid rectal perforation and pelvic sepsis at time of endoscopy. If completion proctectomy is indicated the authors favour removal of the anal canal using an intersphincteric dissection technique.

Evaluation of intestinal microbiota, short-chain fatty acids, and immunoglobulin a in diversion colitis

It is reported that an increase in aerobic bacteria, a lack of short-chain fatty acids (SCFAs), and immune disorders in the diverted colon are major causes of diversion colitis. However, the precise pathogenesis of this condition remains unclear. The aim of the present study was to examine the microbiota, intestinal SCFAs, and immunoglobulin A (IgA) in the diverted colon. Eight patients underwent operative procedures for colostomies. We assessed the diverted colon using endoscopy and obtained intestinal samples from the diverted colon and oral colon in these patients. We analyzed the microbiota and SCFAs of the intestinal samples. The bacterial communities were investigated using a 16S rRNA gene sequencing method. The microbiota demonstrated a change in the proportion of some species, especially Lactobacillus, which significantly decreased in the diverted colon at the genus level. We also showed that intestinal SCFA values were significantly decreased in the diverted colon. Furthermore, intestinal IgA levels were significantly increased in the diverted colon. This study was the first to show that intestinal SCFAs were significantly decreased and intestinal IgA was significantly increased in the diverted colon. Our data suggest that SCFAs affect the microbiota and may play an immunological role in diversion colitis.

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Anaerobic bacteria like Lactobacillus significantly decreased in the diverted colon.

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Fecal short-chain fatty acids significantly decreased in the diverted colon.

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Acetic acid also decreased significantly in the diverted colon.

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Fecal immunoglobulin A levels were significantly increased in the diverted colon.

The surgical treatment of acute and severe diversion colitis mimicking ulcerative colitis: a case report

BACKGROUND

Diversion colitis (DC) is characterized by nonspecific inflammation in the remaining colon or rectum, and loss of the fecal stream plays a major role in the disease's development. Although the majority of patients are asymptomatic, medical and/or surgical treatment is required for those who are symptomatic. There is a particular interest on how to manage patients with acute and severe clinical presentations, but the pathogenesis is not fully understood. We report the rare case of a man with acute and severe DC mimicking ulcerative colitis (UC) with extra-intestinal manifestations that was successfully managed with surgical treatment.

CASE PRESENTATION

A 68-year-old man with a history of laparoscopic intersphincteric resection of the rectum with diverting loop ileostomy for lower rectal cancer suffered from anastomotic stenosis requiring repeated endoscopic dilatation. His loop stoma was not reversed because these treatments were unsuccessful. He denied having a history of inflammatory bowel disease. Twelve years postoperatively, he developed a perineal abscess requiring drainage. Subsequently, he developed a high-grade fever, bloody discharge per anus, and skin ulcers in the right ankle and around the stoma. Because culture tests were negative for bacteria, it was deemed that his acute illness reflected an inflammatory response rather than an infectious disease. Colonoscopy revealed anastomotic stenosis, a colonic fistula, and mucosa that hemorrhaged easily, with lacerations. A pathological examination with biopsy revealed inflammatory infiltration without malignancy. After reviewing the patient's clinical episodes and discussing the case with physicians in multiple specialties, we performed total colectomy with end ileostomy in accordance with the abdominoperineal resection. The postoperative course was uneventful. A resected specimen showed atrophic mucosa with the disappearance of haustra in the distal colon, as well as edematous and dilated mucosa in the proximal colon. The pathological diagnosis was suggestive of UC, including erosion and ulceration in edematous wall, crypt abscess, and inflammatory infiltration into the mucosa. The skin ulcers in the right ankle and around the stoma healed over time.

CONCLUSIONS

DC can eventuate in a long-term period after fecal diversion surgery, possibly with extra-intestinal manifestations mimicking UC. Surgical treatment seems feasible for patients with acute and severe DC.

Role of short-chain fatty acids in colonic inflammation, carcinogenesis, and mucosal protection and healing

Short-chain fatty acids (SCFAs), mainly acetate, propionate, and butyrate, produced by microbial fermentation of undigested food substances are believed to play a beneficial role in human gut health. Short-chain fatty acids influence colonic health through various mechanisms. In vitro and ex vivo studies show that SCFAs have anti-inflammatory and anticarcinogenic effects, play an important role in maintaining metabolic homeostasis in colonocytes, and protect colonocytes from external harm. Animal studies have found substantial positive effects of SCFAs or dietary fiber on colonic disease, but convincing evidence in humans is lacking. Most human intervention trials have been conducted in the context of inflammatory bowel disease. Only a limited number of those trials are of high quality, showing little or no favorable effect of SCFA treatment over placebo. Opportunities for future research include exploring the use of combination therapies with anti-inflammatory drugs, prebiotics, or probiotics; the use of prodrugs in the setting of carcinogenesis; or the direct application of SCFAs to improve mucosal healing after colonic surgery.

Pathogenesis, diagnosis, and management of ulcerative proctitis, chronic radiation proctopathy, and diversion proctitis

Chronic proctitis refers to persistent or relapsing inflammation of the rectum, which results from a wide range of etiologies with various pathogenic mechanisms. The patients may share similar clinical presentations. Ulcerative proctitis, chronic radiation proctitis or proctopathy, and diversion proctitis are the 3 most common forms of chronic proctitis. Although the diagnosis of these disease entities may be straightforward in the most instances based on the clinical history, endoscopic, and histologic features, differential diagnosis may sometimes become problematic, especially when their etiologies and the disease processes overlap. The treatment for the 3 forms of chronic proctitis is different, which may shed some lights on their pathogenetic pathway. This article provides an overview of the latest data on the clinical features, etiologies, diagnosis, and management of ulcerative proctitis, chronic radiation proctopathy, and diversion proctitis.

Pathophysiology, clinical presentation and management of diversion colitis: a review of current literature

INTRODUCTION

Diversion colitis is a non-specific inflammation of a de-functioned segment of intestine after diversion of the faecal stream.

AIM

The aim of this study was to review the current level of knowledge about diversion colitis.

METHODS

A literature search of relevant literature in the English language was carried out on PUBMED, MEDLINE and EMBASE. The following keywords were used: diversion colitis; disuse colitis; proctitis; colonic bacterial flora; stoma; de-functioned colon; faecal diversion; short chain fatty acids and lymphoid follicular hyperplasia.

RESULTS

In total 35 articles met the inclusion criteria. 22 were case series, 9 were case reports, 2 were retrospective analysis and 2 were prospective randomized controlled studies. Diversion colitis is invariably present in all diverted segments of the colon. It is usually asymptomatic but can present with tenesmus, rectal discharge, bleeding per rectum and abdominal pain. Major macroscopic changes include mucosal nodularity, erythema and friability. Microscopic features are predominantly those of lymphoid follicular hyperplasia, apthous ulceration and chronic inflammatory changes, mostly limited to sub mucosa. Treatment modalities include surveillance for asymptomatic patients, restoration of bowel continuity for severely symptomatic cases and the use of short chain fatty acid (SCFA) enemas in selected cases.

CONCLUSION

The clinical presentation of diversion colitis varies significantly. In symptomatic patients short chain fatty acid enema may help. Further prospective studies are required for evaluation.

Comparison of prophylactic and therapeutic use of short-chain fatty acid enemas in diversion colitis: a study in Wistar rats

OBJECTIVES

To study the effect of short-chain fatty-acids on atrophy and inflammation of excluded colonic segments before and after the development of diversion colitis.

INTRODUCTION

Diversion colitis is a chronic inflammatory process affecting the dysfunctional colon, possibly evolving with mucous and blood discharge. The most favored hypotheses to explain its development is short-chain fatty-acid deficiency in the colon lumen.

METHODS

Wistar rats were submitted to colostomy with distal colon exclusion. Two control groups (A1 and B1) received rectally administered physiological saline, whereas two experimental groups (A2 and B2) received rectally administered short-chain fatty-acids. The A groups were prophylactically treated (5th to 40th days postoperatively), whereas the B groups were therapeutically treated (after post-operative day 40). The mucosal thickness of the excluded colon was measured histologically. The inflammatory reaction of the mucosal lamina propria and the lymphoid tissue response were quantified through established scores.

RESULTS

There was a significant thickness recovery of the colonic mucosa in group B2 animals (p = 0.0001), which also exhibited a significant reduction in the number of eosinophilic polymorphonuclear cells in the lamina propria (p = 0.0126) and in the intestinal lumen (p = 0.0256). Group A2 showed no mucosal thickness recovery and significant increases in the numbers of lymphocytes (p = 0.0006) and eosinophilic polymorphonuclear cells in the lamina propria of the mucosa (p = 0.0022).

CONCLUSION

Therapeutic use of short-chain fatty-acids significantly reduced eosinophilic polymorphonuclear cell numbers in the intestinal wall and in the colonic lumen; it also reversed the atrophy of the colonic mucosa. Prophylactic use did not impede the development of mucosal atrophy.

High proportions of proinflammatory bacteria on the colonic mucosa in a young patient with ulcerative colitis as revealed by cloning and sequencing of 16S rRNA genes

The pathogenesis of ulcerative colitis (UC) remains unknown. It is thought to be due to an abnormal and uncontrolled immune response to normally occurring constituents of the intestine. Microbial agents appear to be involved in the pathogenesis and intestinal bacteria seem to be an important factor in the development and chronicity. The aim of this study was to investigate the colonic microbiota of a patient with UC. The colonic tissues were taken during surgery from a 12-year-old girl suffering from UC. The microbiota on the colonic samples was studied by cloning and sequencing of amplified 16S rRNA genes. Compared with healthy subjects, alteration of the dominant bacterial group was observed in the UC patient. We found a high incidence of Enterobacteriaceae, Bacteroides fragilis, and the single phylotype of the Faecalibacterium prausnitzii-like "Butyrate-producing bacterium" L2-6. Furthermore, there was a substantial presence of Pseudomonas aeruginosa in the present case of UC. The high proportion of adverse proinflammatory species is striking in the present case compared with more normal situations. Even if those bacteria are not the cause of the UC, they most probably enhance the symptoms of the disease.