Colorectal cancer screening and surveillance in patients with inflammatory bowel disease in 2021

Escherichia coli Nissle 1917 Protects against Sepsis-Induced Intestinal Damage by Regulating the SCFA/GPRs Signaling Pathway

This study explores whether Escherichia coli Nissle 1917 (EcN) can preserve the integrity of the intestinal barrier by modulating the metabolism pathway of short-chain fatty acids (SCFAs) in a C57BL/6J mouse model of lipopolysaccharide (LPS)-induced acute enteritis and a model of a Caco-2 monolayer. The study involved establishing a septic shock model in mice through lipopolysaccharide (LPS) injection. Clinical scores and intestinal permeability were meticulously documented. Immunofluorescence was utilized to localize the tight junction proteins. A quantitative real-time polymerase chain reaction (qRT-PCR) was employed to assess the expression of G protein-coupled receptors (GPRs) signaling. Additionally, the supplement of acetate and butyrate with Caco-2 monolayers to elucidate the potential of EcN in augmenting the intestinal barrier primarily via the modulation of SCFAs and qRT-PCR was performed to detect the expression of tight junction proteins and the activation of the GPRs protein signaling pathway. EcN mitigated the clinical symptoms and reduced intestinal permeability in the colon of LPS-induced mice. It also enhanced the production of SCFAs in the gut and upregulated the expression of SCFA receptor proteins GPR41 and GPR43 in the colon tissue. Our findings reveal that EcN activates the SCFA/GPRs pathway, thereby preserving intestinal barrier function and alleviating inflammation in a mouse sepsis model.

The Preventive Effect of Low-Molecular Weight Oyster Peptides on Lipopolysaccharide-Induced Acute Colitis in Mice by Modulating Intestinal Microbiota Communities

Colitis causes inflammation, diarrhoea, fever, and other serious illnesses, posing a serious threat to human health and safety. Current medications for the treatment of colitis have serious side effects. Therefore, the new strategy of creating a defence barrier for immune function by adding anti-inflammatory foods to the daily diet is worth advocating for. Low-molecular weight oyster peptides (LOPs) are a natural food with anti-inflammatory activity extracted from oysters, so intervention with LOPs is likely to be an effective preventive solution. The aim of this study was to investigate the preventive effect of LOPs on lipopolysaccharide (LPS)-induced acute colitis inflammation in mice and its underlying mechanism. The results showed that LOPs not only inhibited the colonic histopathy in mice induced by LPS-induced inflammation but also reduced the inflammatory response in the blood. In addition, LOPs significantly increased the number of beneficial bacteria (Alistipes, Mucispirillum, and Oscillospira), decreased the number of harmful bacteria (Coprobacillus, Acinetobater) in the intestinal microbiota, and further affected the absorption and utilisation of short-chain fatty acids (SCFAs) in the intestinal tract. In conclusion, dietary supplementation with LOPs is a promising health-promoting dietary supplement and nutraceutical for the prevention of acute colitis by reducing the inflammatory response and modulating the intestinal microbial communities.

Colorectal Neoplasia in the Setting of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is associated with an increased risk of colorectal cancer (colorectal adenocarcinoma [CRC]) compared with the general population. IBD-related CRC is related to poorer outcomes than non-IBD-related CRC, and it accounts for 10% to 15% of death in patients with IBD. As such, screening guidelines have been made specific to this population recommending shorter intervals of endoscopic screening to detect dysplasia and CRC relative to the general population. Advances in endoscopic technology allow for improved visualization of dysplasia, which has led to widespread adoption of dye-spray chromoendoscopy with targeted biopsy.

Malignant Transformation of Long-Standing Ileal Crohn's Disease Likely Favors Signet Ring Cell Adenocarcinoma Histology

Signet ring cell adenocarcinomas (SRCCs) are a rare and aggressive histological subtype of adenocarcinomas typically with poor prognosis usually secondary to late stage at detection. In the small bowel, they constitute only 1% of all malignancies. In the last decade, there have been multiple case reports and small case series that have identified SRCCs, typically in the ileum, in patients with Crohn's disease. Crohn's disease is a transmural inflammatory condition that normally manifests in the distal ileum and colon, and is known to temporally increase the risk of malignancy. Given the profound rarity of SRCCs, establishing an association between Crohn's disease and SRCC is challenging. In this study, we performed a systematic review of case reports and small case series describing small bowel SRCCs in Crohn's disease patients. Most cases were found in the distal/terminal ileum, at a mean age of 59 years old. Virtually all tumors were locally advanced (pathological T stage 3 and 4), typically with at least N1 nodal disease. Two case studies (one is a case-control study and the other a cohort design) demonstrated that small bowel SRCC, as opposed to conventional adenocarcinoma, was significantly correlated to a history of Crohn's disease (35% vs. 0%, 73.5% vs. 28.5%), with a propensity to arise in the ileum (95% vs. 30%, 66.7% vs. 42.1%), and at earlier mean age (43 vs. 68 years, 53.7 vs. 61.7 years). We additionally used the Surveillance, Epidemiology, and End Results (SEER) database for insights into the clinicoepidemiological characteristics of ileum SRCCs. SRCCs composed 28.1% of all ileal SRCCs, compared to 11.0% for the adenocarcinomas, with a younger age at diagnosis (60.7 vs. 64.6 years), more distant disease at presentation (41.3% vs. 26.4%), and shorter overall median survival time (20 vs. 39 months). In summary, while there is limited direct evidence to support an association between small bowel SRCC and Crohn's disease, the phenomenon has been increasingly documented in the literature in the last decade. Clinicians treating Crohn's disease patients should consider this in their differential diagnosis, particularly when managing disease complications, as early detection and surgical intervention offer the best prognosis.

Inflammatory Bowel Disease and Colorectal Cancer: Epidemiology, Etiology, Surveillance, and Management

Patients with inflammatory bowel diseases (IBDs), such as ulcerative colitis and Crohn's disease, have an increased risk of developing colorectal cancer (CRC). Although advancements in endoscopic imaging techniques, integrated surveillance programs, and improved medical therapies have contributed to a decreased incidence of CRC in patients with IBD, the rate of CRC remains higher in patients with IBD than in individuals without chronic colitis. Patients with IBD-related CRCs exhibit a poorer prognosis than those with sporadic CRCs, owing to their aggressive histological characteristics and lower curative resection rate. In this review, we present an updated overview of the epidemiology, etiology, risk factors, surveillance strategies, treatment recommendations, and prognosis of IBD-related CRCs.

Stromal inflammation, fibrosis and cancer: An old intuition with promising potential

It is now well established that the biology of cancer is influenced by not only malignant cells but also other components of the tumour microenvironment. Chronic inflammation and fibrosis have long been postulated to be involved in carcinogenesis. Chronic inflammation can promote tumorigenesis via growth factor/cytokine-mediated cellular proliferation, apoptotic resistance, immunosuppression; and free-radical-induced oxidative deoxyribonucleic acid damage. Fibrosis could cause a perturbation in the dynamics of the tumour microenvironment, potentially damaging the genome surveillance machinery of normal epithelial cells. In this review, we will provide an in-depth discussion of various diseases characterised by inflammation and fibrosis that have been associated with an increased risk of malignancy. In particular, we will present a comprehensive overview of the impact of alterations in stromal composition on tumorigenesis, induced as a consequence of inflammation and/or fibrosis. Strategies including the application of various therapeutic agents with stromal manipulation potential and targeted cancer screening for certain inflammatory diseases which can reduce the risk of cancer will also be discussed.

The preventive effect of Glycyrrhiza polysaccharide on lipopolysaccharide-induced acute colitis in mice by modulating gut microbial communities

Acute colitis is characterised by an unpredictable onset and causes intestinal flora imbalance together with microbial migration, which leads to complex parenteral diseases. Dexamethasone, a classic drug, has side effects, so it is necessary to use natural products without side effects to prevent enteritis. Glycyrrhiza polysaccharide (GPS) is an α-d-pyranoid polysaccharide with anti-inflammatory effects; however, its anti-inflammatory mechanism in the colon remains unknown. This study investigated whether GPS reduces the lipopolysaccharide (LPS)-induced inflammatory response in acute colitis. The results revealed that GPS attenuated the upregulation of tumour necrosis factor-α, interleukin (IL)-1β, and IL-6 in the serum and colon tissues and significantly reduced the malondialdehyde content in colon tissues. In addition, the 400 mg/kg GPS group showed higher relative expressions of occludin, claudin-1, and zona occludens-1 in colon tissues and lower concentrations of diamine oxidase, D-lactate, and endotoxin in the serum than the LPS group did, indicating that GPS improved the physical and chemical barrier functions of colon tissues. GPS increased the abundance of beneficial bacteria, such as Lactobacillus, Bacteroides, and Akkermansia, whereas pathogenic bacteria, such as Oscillospira and Ruminococcus were inhibited. Our findings indicate that GPS can effectively prevent LPS-induced acute colitis and exert beneficial effects on the intestinal health.

Molecular characterization of visible low-grade dysplastic lesions in patients with inflammatory bowel disease

We studied pathogenic gene mutations and tumor mutation burden (TMB) in visible low-grade dysplastic lesions in patients with inflammatory bowel disease (IBD). The dysplastic lesions with histologically normal mucosa in the background (group 1) were compared with dysplastic lesions occurring either in a background of chronic active colitis (group 2) or associated with synchronous carcinomas regardless of the status of the background mucosa (group 3). The TMB in group 3 was consistently higher in comparison to the group 1 and group 2 lesions, although the difference was not statistically significant. There also seem to be different mutation profiles between the groups, indicating different pathways of tumor pathogenesis. More frequent APC mutations were seen in group 1 as compared to other groups and TP53 mutations were seen in groups 2 and 3, but none in group 1. Molecular characterization could potentially be used as an ancillary prognostic marker in challenging cases to guide the further management of IBD patients with visible dysplastic lesions.

Incremental Detection Rate of Dysplasia and Sessile Serrated Polyps/Adenomas Using Narrow-Band Imaging and Dye Spray Chromoendoscopy in Addition to High-Definition Endoscopy in Patients with Long-Standing Extensive Ulcerative Colitis: Segmental Tandem Endoscopic Study

High-definition (HD) endoscopy is recommended in surveillance colonoscopy for detecting dysplasia in patients with ulcerative colitis (UC). Dye-spray chromoendoscopy (DCE) and narrow-band imaging (NBI) are often used as adjunctive techniques of white-light endoscopy (WLE) in real-world practice. However, the incremental detection ability of DCE and NBI added to HD-WLE for dysplasia and serrated lesions has not yet been evaluated using tandem endoscopy in patients with long-standing extensive UC. We enrolled patients with extensive UC for >8 years who were in clinical remission (partial Mayo score < 2) at the Samsung Medical Center in Seoul, Republic of Korea. HD-WLE was performed first. Subsequently, HD-NBI and HD-DCE with indigo carmine were performed using the segmental tandem colonoscopy technique. A total of 40 patients were eligible, and data obtained from 33 patients were analyzed. The incremental detection rates (IDRs) for dysplasia and serrated lesions were calculated. HD-WLE detected three dysplasia and five sessile serrated adenomas/polyps (SSAs/Ps). HD-NBI and HD-DCE did not detect additional dysplasia (IDR = 0%; 95% confidence interval (CI): 0-56.2%). HD-NBI identified one missed SSA/P (IDR = 7.7%; 95% CI: 1.4-33.3%), and HD-DCE detected seven missed SSAs/Ps (IDR = 53.9%; 95% CI: 29.1-76.8%). Logistic regression found that HD-DCE increased the detection of SSAs/Ps compared to HD-WLE and/or HD-NBI (odds ratio (OR) = 3.16, 95% CI: 0.83-11.92, p = 0.08). DCE in addition to HD-WLE improved the detection of SSAs/Ps, but not dysplasia, in patients with long-standing extensive UC.

Artificial Intelligence in Inflammatory Bowel Disease Endoscopy: Advanced Development and New Horizons

Inflammatory bowel disease (IBD) is a complex chronic immune disease with two subtypes: Crohn's disease and ulcerative colitis. Considering the differences in pathogenesis, etiology, clinical presentation, and response to therapy among patients, gastroenterologists mainly rely on endoscopy to diagnose and treat IBD during clinical practice. However, as exemplified by the increasingly comprehensive ulcerative colitis endoscopic scoring system, the endoscopic diagnosis, evaluation, and treatment of IBD still rely on the subjective manipulation and judgment of endoscopists. In recent years, the use of artificial intelligence (AI) has grown substantially in various medical fields, and an increasing number of studies have investigated the use of this emerging technology in the field of gastroenterology. Clinical applications of AI have focused on IBD pathogenesis, etiology, diagnosis, and patient prognosis. Large-scale datasets offer tremendous utility in the development of novel tools to address the unmet clinical and practice needs for treating patients with IBD. However, significant differences among AI methodologies, datasets, and clinical findings limit the incorporation of AI technology into clinical practice. In this review, we discuss practical AI applications in the diagnosis of IBD via gastroenteroscopy and speculate regarding a future in which AI technology provides value for the diagnosis and treatment of IBD patients.