The role of infection in the aetiology of inflammatory bowel disease

Efficacy of curcumin supplementation for the treatment and prevention of pouchitis after ileal pouch-anal anastomosis: a randomized controlled trial

BACKGROUND

Pouchitis is the most common complication after ileal pouch-anal anastomosis (IPAA) for ulcerative colitis. Induction and maintenance of remission is a crucial therapeutic goal. We investigated curcumin's efficacy in treatment of pouchitis.

METHODS

The double-blind trial included an induction cohort of refractory pouchitis patients and a maintenance cohort of patients without pouchitis after IPAA. Patients received either placebo or curcumin for 8 weeks. The pouchitis activity were assessed before and after and was compared between cohorts or groups. Laboratory inflammation indicators, nutritional status and quality of life were also appraised.

RESULTS

52 patients were included, with 39 and 13 patients entering the maintenance cohort and induction cohort, respectively. In maintenance cohort, the proportion of clinical remission elevated from 11 to 89% in curcumin group (p = 0.005), whereas there was no significant difference in placebo group (10% vs 5%, p = 1).In induction cohort, 67% (4/6) patients achieved clinical response after 8 weeks' intervention of curcumin, whereas none treated with placebo (p = 0.021). Patients treated with curcumin appeared less inflammation and there was no significant difference in indicators changes between two cohorts.

CONCLUSIONS

Curcumin has preventive and therapeutic effects on pouchitis. Curcumin supplementation can reduce the disease activity and improve the nutritional status of patients with after IPAA.

TRIAL REGISTRATION

ChiCTR, ChiCTR1900022243. Registered 31 March 2019, https://www.chictr.org.cn/historyversionpub.aspx?regno=ChiCTR1900022243.

Inflammatory bowel disease is associated with greater odds of complications following posterior lumbar fusion and further amplified for patients exposed to monoclonal antibody biologics

Background

Posterior lumbar fusion (PLF) is a common spine surgery that may be considered in patients with underlying comorbidities, such as inflammatory bowel disease (IBD). Prior literature examining the association of this disease and PLF outcomes was done in the National Inpatient Sample (NIS), which only assessed in-hospital data and did not reveal an elevated risk of medical or surgical complications. However, characterization of PLF outcomes beyond hospital discharge is important and remains unknown for patients with IBD.

Methods

Patients with IBD who underwent single-level PLF ± interbody fusion were identified from the M165Ortho PearlDiver database. Exclusion criteria included: patients <18 years old, those undergoing concurrent cervical, thoracic, anterior, or multi-level fusion, those with prior trauma, neoplasm, or infection diagnosed within 90-days, and <90-days of follow-up. Adult patients with IBD were matched 1:4 with non-IBD patients based on age, sex, and Elixhauser Comorbidity Index (ECI). The odds of 90-day individual and aggregated any, severe, and minor adverse events (AAE, SAE, and MAE, respectively), emergency department (ED) visits, and hospital readmission were compared by multivariable logistic regression. Five-year reoperation was assessed by Kaplan-Meier survival analysis and compared by log-rank test.

Results

Overall, 4,392 (1.4%) of patients undergoing PLF were identified with IBD. These patients demonstrated elevated odds ratios (ORs) of aggregated MAE (OR 2.29), AAE (OR 2.27), and SAE (OR 1.84), as well as ED visits (OR 2.69) (p<.001 for all). Conversely, 5-year reoperation rates were not different for those with vs without IBD (p=.70).

Conclusions

The current study highlights the importance of investigating post-discharge outcomes, as these findings were not detected by prior inpatient literature. Our findings reveal the odds of various complications may be significantly elevated for IBD patients within 90-days postoperatively, however, these inferior outcomes encouragingly did not translate to an elevated rate of 5-year reoperation.

A diagnostic dilemma: cytomegalovirus colitis as an uncommon comorbidity in inflammatory bowel disease: a case report

BACKGROUND

The role of cytomegalovirus infection as an opportunistic pathogen in exacerbating ulcerative colitis and its response to treatment remain a topic of ongoing debate. Clinicians encounter numerous challenges, including the criteria for differentiating between an acute ulcerative colitis flare and true cytomegalovirus colitis, the diagnostic tests for identifying cytomegalovirus colitis, and determining the appropriate timing for initiating antiviral therapy.

CASE PRESENTATION

A 28-year-old Syrian female with a seven-year history of pancolitis presented with worsening bloody diarrhea, abdominal pain, and tenesmus despite ongoing treatment with azathioprine, mesalazine, and prednisolone. She experienced a new flare of acute severe ulcerative colitis despite recently completing two induction doses of infliximab (5 mg/kg) initiated four weeks prior for moderate-to-severe ulcerative colitis. She had no prior surgical history. Her symptoms included watery, bloody diarrhea occurring nine to ten times per day, abdominal pain, and tenesmus. Initial laboratory tests indicated anemia, leukocytosis, elevated C-reactive protein (CRP) and fecal calprotectin levels, and positive CMV IgG. Stool cultures, Clostridium difficile toxin, testing for Escherichia coli and Cryptosporidium, and microscopy for ova and parasites were all negative. Sigmoidoscopy revealed numerous prominent erythematous area with spontaneous bleeding. Biopsies demonstrated CMV inclusions confirmed by immunohistochemistry, although prior biopsies were negative. We tapered prednisolone and azathioprine and initiated ganciclovir at 5 mg/kg for ten days, followed by valganciclovir at 450 mg twice daily for three weeks. After one month, she showed marked improvement, with CRP and fecal calprotectin levels returning to normal. She scored one point on the partial Mayo score. The third induction dose of infliximab was administered on schedule, and azathioprine was resumed.

CONCLUSION

Concurrent cytomegalovirus infection in patients with inflammatory bowel disease presents a significant clinical challenge due to its associated morbidity and mortality. Diagnosing and managing this condition is particularly difficult, especially regarding the initiation or continuation of immunosuppressive therapies.

Impact of COVID-19 on Pediatric Inflammatory Bowel Diseases-From Expectations to Reality

Viral infections have always been considered a threat to global health, with numerous outbreaks across time. Despite the relative recent experience with coronavirus-associated diseases such as severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), severe acute respiratory syndrome-2's (SARS-CoV-2) continuous evolution displays a different behavior. With a tropism for both respiratory and digestive mucosa, coronavirus disease 2019 (COVID-19) and inflammatory bowel disease (IBD) seem to share a particular common background. Current literature offers evidence that viral alteration of the immune system, inflammatory intestinal tissue damage, increased intestinal permeability, incomplete viral clearance with viral antigen persistence, and intestinal dysbiosis, might explain SARS-CoV-2-IBD relationship in terms of etiopathogenesis and evolution. The hyperinflammatory state that both entities have in common explains the lack of success of current IBD therapy, raising the need for new personalized therapeutic options, with better outcomes for IBD and COVID-19 as well. This review aims to summarize the current available data on pediatric IBD evolution, management, and outcomes in the post-COVID period, with an emphasis on the particular aspects of the SARS-CoV-2-IBD relationship in children.

Factors influencing the quality of life in inflammatory bowel disease: A comprehensive review

Inflammatory bowel disease (IBD) is a group of chronic relapsing disorders, including Crohn's disease (CD) and ulcerative colitis (UC), which affects an increasing number of people worldwide. In the last few decades, the scientific world has witnessed many developments in IBD management by controlling debilitating symptoms and remaining in remission for more protracted periods. Even so, we still have a large population suffering from active IBD. An individual's quality of life (QoL) can be severely affected by IBD, like any other chronic illness. In this article, we have reviewed factors influencing the QoL in IBD patients, including chronic pain, diet, physical activity, and psychological factors like depression, anxiety, and stress symptoms. We also discussed the mechanisms of diet-microbial-immune system interaction, currently available dietary therapies for active CD and UC, and early psycho-social interventions that can reduce the disease burden and improve QoL in IBD patients.

Gut-brain axis interacts with immunomodulation in inflammatory bowel disease

The brain and the gastrointestinal (GI) tract are important sensory organs in the body and the two-way interaction that exists between them regulates key physiological and homeostatic functions. A growing body of research suggests that this bidirectional communication influences the development and progression of functional GI disorders and plays an important role in the treatment of central nervous system (CNS) disorders. Inflammatory bowel disease (IBD) is a classic intestinal disorder with a high prevalence but still unclear pathogenesis that has been widely discussed in recent years. However, in the studies available to date, we find that many authors have chosen to discuss the influence of the brain on intestinal disorders from the top down, starting with physical and psychological disorders. Coming very naturally, based on these substantial research evidence, we focus on exploring the links between bidirectional communication in the gut-brain axis and IBD, and highlight the role of the gut microbiota, vagus nerve (VN), receptors and immune cells involved in regulating IBD through the gut-brain axis in this review.

Sarcoidosis, Mycobacterium paratuberculosis and Noncaseating Granulomas: Who Moved My Cheese

Clinical and histological similarities between sarcoidosis and tuberculosis have driven repeated investigations looking for a mycobacterial cause of sarcoidosis. Over 50 years ago, "anonymous mycobacteria" were suggested to have a role in the etiology of sarcoidosis. Both tuberculosis and sarcoidosis have a predilection for lung involvement, though each can be found in any area of the body. A key histopathologic feature of both sarcoidosis and tuberculosis is the granuloma-while the tuberculous caseating granuloma has an area of caseous necrosis with a cheesy consistency; the non-caseating granuloma of sarcoidosis does not have this feature. This article reviews and reiterates the complicity of the infectious agent, Mycobacterium avium subsp. paratuberculosis (MAP) as a cause of sarcoidosis. MAP is involved in a parallel story as the putative cause of Crohn's disease, another disease featuring noncaseating granulomas. MAP is a zoonotic agent infecting ruminant animals and is found in dairy products and in environmental contamination of water and air. Despite increasing evidence tying MAP to several human diseases, there is a continued resistance to embracing its pleiotropic roles. "Who Moved My Cheese" is a simple yet powerful book that explores the ways in which individuals react to change. Extending the metaphor, the "non-cheesy" granuloma of sarcoidosis actually contains the difficult-to-detect "cheese", MAP; MAP did not move, it was there all along.

Pentosan Polysulfate Sodium augments the therapeutic effect of 5-Aminosalicylic Acid in DSS colitis model; the role of IL-35 expression

Ulcerative colitis (UC) primarily affects the mucosa of the distal colon. Dysregulated immune response in genetically-prone persons is claimed to be responsible for chronic intestinal inflammation. This study aimed to explore the efficacy and the hematological effects of pentosan polysulfate sodium (PPS) in a dextran sulfate sodium (DSS)-induced colitis model. Forty C57BL/6 female mice were equally divided into five groups: control group, DSS-colitis group, DSS-colitis treated with 5-aminosalicylic acid, DSS-colitis treated with PPS, and DSS-colitis treated with both drugs. Disease activity index (DAI) and colon length were calculated. Colonic IL-6 and IL-35 levels were assayed by ELISA. IL-35 gene expression was evaluated by qRT-PCR. Colon tissue samples were examined by H&E stain and immunohistochemistry (IHC) of Ki67. The colitis group subjected to combined treatment showed the best outcome with significant improvement of DAI and increased colon length. Colonic IL-6 was significantly lower in both PPS- and combination-treated groups accompanied by a significantly higher IL-35 level and its EBI3 subunit mRNA expression. However, the PPS-treated colitis group showed higher gene expression of IL-35 EBI3 subunit by 1.5-fold compared with the combined group. The colon mucosa and crypts were significantly preserved in mice treated with both drugs with the best Ki67 positive cell density. PPS is a safe and promising drug in the treatment of UC as it exerted the best positive effect on the anti-inflammatory IL-35 level and gene expression. However, superior improvement of DAI was seen when PPS was added to ASA with a greater mucosal proliferation and repair.

Discovery of Pyrazolo[3,4-d]pyridazinone Derivatives as Selective DDR1 Inhibitors via Deep Learning Based Design, Synthesis, and Biological Evaluation

Alterations of discoidin domain receptor1 (DDR1) may lead to increased production of inflammatory cytokines, making DDR1 an attractive target for inflammatory bowel disease (IBD) therapy. A scaffold-based molecular design workflow was established and performed by integrating a deep generative model, kinase selectivity screening and molecular docking, leading to a novel DDR1 inhibitor compound 2, which showed potent DDR1 inhibition profile (IC₅₀ = 10.6 ± 1.9 nM) and excellent selectivity against a panel of 430 kinases (S (10) = 0.002 at 0.1 μM). Compound 2 potently inhibited the expression of pro-inflammatory cytokines and DDR1 autophosphorylation in cells, and it also demonstrated promising oral therapeutic effect in a dextran sulfate sodium (DSS)-induced mouse colitis model.

Interaction Between Commensal Bacteria, Immune Response and the Intestinal Barrier in Inflammatory Bowel Disease

In inflammatory bowel disease (IBD), intestinal mucosa cell and intestinal epithelial cell are severely damaged, and then their susceptibility to bacteria increases, so many commensal bacteria become pathogenic. The pathogenic commensal bacteria can stimulate a series of compensatory immune responses in the intestine. However, the immune response prevents the intestinal tract from restoring homeostasis, which in turn produces an indispensable inflammatory response. On the contrary, in IBD, the fierce inflammatory response contributes to the development of IBD. However, the effect of commensal bacteria on inflammation in IBD has not been clearly studied. Therefore, we further summarize the changes brought about by the changes of commensal bacteria to the inflammation of the intestines and their mutual influence. This article reviews the protective mechanism of commensal bacteria in healthy people and the mechanism of commensal bacteria and immune response to the destruction of the intestinal barrier when IBD occurs. The treatment and prevention of IBD are also briefly summarized.

Bacteriocins: Recent advances in application as an antimicrobial alternative

Due to the emergence and development of antibiotic resistance in the treatment of bacterial infections, efforts to discover new antimicrobial agents have increased. One of these antimicrobial agents is a compound produced by a large number of bacteria called bacteriocin. Bacteriocins are small ribosomal polypeptides that can exert their antibacterial effects against bacteria close to their producer strain or even non-closely strains. Adequate knowledge of the structure and functional mechanisms of bacteriocins and their spectrum of activity, as well as knowledge of the mechanisms of possible resistance to these compounds will lead to further development of their use as an alternative to antibiotics. Furthermore, most bacteria that live in the gastrointestinal tract (GIT) have the ability to produce bacteriocins, which spread throughout the GIT. Despite antimicrobial studies in vitro, our knowledge of bacteriocins in the GIT and the migration of these bacteriocins from the epithelial barrier is low. Hence, in this study, we reviewed general information about bacteriocins, such as classification, mechanism of action and resistance, emphasizing their presence, stability, and spectrum of activity in the GIT.

Health benefits of edible mushroom polysaccharides and associated gut microbiota regulation

Edible mushrooms have been an important part of the human diet for thousands of years, and over 100 varieties have been cultivated for their potential human health benefits. In recent years, edible mushroom polysaccharides (EMPs) have been studied for their activities against obesity, inflammatory bowel disease (IBD), and cancer. Particularly, accumulating evidence on the exact causality between these health risks and specific gut microbiota species has been revealed and characterized, and most of the beneficial health effects of EMPs have been associated with its reversal impacts on gut microbiota dysbiosis. This demonstrates the key role of EMPs in decreasing health risks through gut microbiota modulation effects. This review article compiles and summarizes the latest studies that focus on the health benefits and underlying functional mechanisms of gut microbiota regulation via EMPs. We conclude that EMPs can be considered a dietary source for the improvement and prevention of several health risks, and this review provides the theoretical basis and technical guidance for the development of novel functional foods with the utilization of edible mushrooms.

Animal models for inducing inflammatory bowel diseases: integrative review

Objective: To identify and describe comparatively the chemical models of the induction of inflammatory bowel diseases (IBD) in rodents most used and that best mimic the pathogenesis in humans. Methods: Based on an integrative review in the MEDLINE and LILACS databases, it was investigated which experimental induction models were most cited in articles published from 2004 to 2020, with the descriptors "Colitis/CI", "Colitis model ulcerative" and "Intestinal inflammation model." All empirical articles that addressed one or more inflammation models in rats or mice were included. Results: 239 articles were identified; of these, only ten empirical articles were selected. The most used models were colitis induced by TNBS acid, DSS, and colitis induced by acetic acid (AA). Conclusion: It was possible to identify the most used models to promote the induction of intestinal inflammation in rats, and both models proved to be effective according to the limitations observed in the models described, suggesting the need for new works that use more well-defined protocols and that more fully represent the pathophysiological complexity of the disease.

Study of microbiome changes in patients with ulcerative colitis in the Central European part of Russia

Ulcerative colitis (UC) is an inflammatory disease that affects the colon and rectum. Recently, evidence has emerged about the influence of microbiota on the development of this disease. However, studies on the role of intestinal microbiota in the pathogenesis of UC have been incomplete. In addition, there are no comprehensive studies of the causes of ulcerative colitis and data on the microbiological composition of the intestines of patients with ulcerative colitis in Russia. We carried out a study of the microbiological composition of the intestines of patients with ulcerative colitis and healthy individuals. We found significant changes in the bacteria genera and species in patients with UC compared with the control group using sequencing on the IonTorrent PGM system and subsequent data analysis. In our study we observed a significant increase of the genus Haemophilus, Olsenella, Prevotella, Cedecea, Peptostreptococcus, Faecalibacterium, Lachnospira, Negativibacillus, Butyrivibrio, and the species Bacteroides coprocola, Phascolarctobacterium succinatutens, Dialister succinatiphilus, Sutterella wadsworthensis, Faecalibacterium prausnitzii in patients with ulcerative colitis. In addition, in patients with ulcerative colitis there was a significant decrease in the genus Fusicatenibacter, Butyricimonas, Lactococcus, Eisenbergiella, Coprobacter, Cutibacterium, Falsochrobactrum, Brevundimonas, Yersinia, Leuconostoc and in the species Fusicatenibacter saccharivorans. We found confirmation of our data with literary sources and studies of UC. In addition, we discovered a few taxa such as Negativibacillus spp. and Falsochrobactrum spp. that have not been previously found in human stool samples. Our data confirm that more research is needed to understand the role of microbiome changes in the development of UC in different people populations.

Crohn’s strictures open with anti-mycobacterial antibiotic therapy: A retrospective review

BACKGROUND

Medical therapy for strictures is limited and first-line treatment consists of endoscopic balloon dilatation, strictureplasty or surgical resection. Mycobacterium tuberculosis, Helicobacter pylori and Streptococcus can all cause stenosis, for which antibiotic treatment achieves stricture resolution. Mycobacterium avium ssp. paratuberculosis is a suspected causative agent in Crohn’s disease (CD). Thus, specialized antimicrobial treatment, in particular, anti-mycobacterial antibiotic therapy (AMAT) has been proposed as a potential treatment option. To our knowledge, the opening of CD strictures has not been recorded using any form of antibiotic therapy. We hypothesized that AMAT would resolve strictures in patients with CD.

AIM

To investigate the effect and outcomes of AMAT in a cohort of CD patients with an ileal stricture.

METHODS

A single center, retrospective, medical record case review was conducted on an observational cohort of patients with CD who had an ileal stricture on colonoscopy and were treated with AMAT. Forty patients meeting the inclusion criteria were identified from the internal medical database. Thirty (75%) patients had follow-up colonoscopy and clinical data available. The AMAT regimen was prescribed after the initial colonoscopy for a duration of at least six months until follow-up colonoscopy with the attending gastroenterologist. Patient demographics, symptoms, colonoscopy reports, inflammatory serum markers and concurrent medications were recorded at pre-treatment and follow-up between January 1995 and June 2018.

RESULTS

Of the patients that returned for follow-up after > 24 mo of AMAT, twenty (67%) had complete resolution (CR) of their ileal strictures, three (10%) had partial resolution and seven (23%) had no resolution. Irrespective of stricture outcome, 21 patients (70%) demonstrated clinical response to AMAT and there was a statistically significant reduction in inflammatory serum markers C-reactive protein (P < 0.0001) and erythrocyte sedimentation rate (P = 0.04) from pre-treatment to follow-up. It was observed that 11 (37%) patients experienced side effects, but no serious adverse effects were attributable to AMAT. At follow-up there were 26 (87%) patients on concomitant medication for CD and a statistically significant association between CR and AMAT with a concomitant immunomodulator (P = 0.02).

CONCLUSION

This study demonstrated a high rate of stricture resolution (67%) similar to that seen in tuberculosis strictures (70%), suggesting a shared mycobacterial origin of strictures, and perhaps disease.

Inflammatory Bowel Disease: The Emergence of New Trends in Lifestyle and Nanomedicine as the Modern Tool for Pharmacotherapy

The human intestine, which harbors trillions of symbiotic microorganisms, may enter into dysbiosis when exposed to a genetic defect or environmental stress. The naissance of chronic inflammation due to the battle of the immune system with the trespassing gut bacteria leads to the rise of inflammatory bowel disease (IBD). Though the genes behind the scenes and their link to the disease are still unclear, the onset of IBD occurs in young adults and has expanded from the Western world into the newly industrialized countries. Conventional drug deliveries depend on a daily heavy dosage of immune suppressants or anti-inflammatory drugs targeted for the treatment of two types of IBD, ulcerative colitis (UC) and Crohn's disease (CD), which are often associated with systemic side effects and adverse toxicities. Advances in oral delivery through nanotechnology seek remedies to overcome the drawbacks of these conventional drug delivery systems through improved drug encapsulation and targeted delivery. In this review, we discuss the association of genetic factors, the immune system, the gut microbiome, and environmental factors like diet in the pathogenesis of IBD. We also review the various physiological concerns required for oral delivery to the gastrointestinal tract (GIT) and new strategies in nanotechnology-derived, colon-targeting drug delivery systems.

Review article: how the intestinal microbiota may reflect disease activity and influence therapeutic outcome in inflammatory bowel disease

BACKGROUND

Intestinal bacteria produce metabolites and by-products necessary for homeostasis. Imbalance in this equilibrium is linked to multiple pathologies including inflammatory bowel disease (IBD). The role of the gut microbiota in determining treatment response is becoming apparent, and may act as biomarker for efficacy.

AIM

To describe knowledge about the intestinal microbiota on disease severity and treatment outcomes in IBD METHODS: Descriptive review using PubMed to identify literature on the intestinal microbiota in IBD RESULTS: Severe IBD has a less diverse microbiota with fewer commensal microbiota communities and more opportunistic pathogenic bacteria originating from the oral cavity or respiratory tract. IBD treatments can alter gut microbiota composition, but in vitro/in vivo studies are needed to prove causation. A diversification of the microbiota is observed during remission. Patients with a more diverse baseline microbiome and higher microbial diversity show better response to anti-tumour necrosis factor-α, vedolizumab and ustekinumab therapy. Higher abundance of short chain fatty acid-producing bacteria, fewer mucus-colonising bacteria and lower abundance of pro-inflammatory bacteria have also been associated with a favourable outcome. Predictive models, based on a combination of microbiota, clinical data and serological markers, have good accuracy for treatment outcome and disease severity.

CONCLUSION

The intestinal microbiota in IBD carries a set of promising biomarkers of disease activity and prediction of therapeutic outcome. Current insights may also help in designing microbiota modulation strategies to improve outcomes in IBD.

Does Ulcerative Colitis Influence the Inter-individual Heterogeneity of the Human Intestinal Mucosal Microbiome?

The dysbiosis of the gut microbiome associated with ulcerative colitis (UC) has been extensively studied in recent years. However, the question of whether UC influences the spatial heterogeneity of the human gut mucosal microbiome has not been addressed. Spatial heterogeneity (specifically, the inter-individual heterogeneity in microbial species abundances) is one of the most important characterizations at both population and community scales, and can be assessed and interpreted by Taylor’s power law (TPL) and its community-scale extensions (TPLEs). Due to the high mobility of microbes, it is difficult to investigate their spatial heterogeneity explicitly; however, TPLE offers an effective approach to implicitly analyze the microbial communities. Here, we investigated the influence of UC on the spatial heterogeneity of the gut microbiome with intestinal mucosal microbiome samples collected from 28 UC patients and healthy controls. Specifically, we applied Type-I TPLE for measuring community spatial heterogeneity and Type-III TPLE for measuring mixed-species population heterogeneity to evaluate the heterogeneity changes of the mucosal microbiome induced by UC at both the community and species scales. We further used permutation test to determine the possible differences between UC patients and healthy controls in heterogeneity scaling parameters. Results showed that UC did not significantly influence gut mucosal microbiome heterogeneity at either the community or mixed-species levels. These findings demonstrated significant resilience of the human gut microbiome and confirmed a prediction of TPLE: that the inter-subject heterogeneity scaling parameter of the gut microbiome is an intrinsic property to humans, invariant with UC disease.

Endoscopic alterations in Peyer's patches in patients with ulcerative colitis: A prospective, multicenter study

BACKGROUND AND AIM

Peyer's patches (PPs) play a major role in intestinal mucosal immunity; however, their role in ulcerative colitis (UC) is not well investigated. We evaluated endoscopic features of PPs on narrow-band imaging with magnifying endoscopy (NBI-ME) and investigated their association with clinical factors.

METHODS

We prospectively recruited 105 patients with UC, 18 with Crohn's disease, 16 with disease control, and 33 healthy control subjects at three institutions from 2014 to 2017. NBI-ME images of the villi of PPs were evaluated according to the Villi Index, and patients were divided into the Villi Index low (L) and high (H) types. The 1-year sustained clinical remission rate was evaluated between L-type and H-type PPs in patients with UC.

RESULTS

The proportions of patients with H-type PPs were significantly higher among UC, Crohn's disease, and disease control patients than among healthy control patients (P = 0.0125, 0.018, 0.0007). In UC, age, gender, endoscopic score, and extent of disease involvement were not significantly different between L-type and H-type PPs, whereas the sustained clinical remission rate was significantly higher in L-type PPs than in H-type PPs (88% [57/65] vs 65% [17/26], P = 0.019). Multivariate analysis revealed that the L type of PPs was a significant factor for sustained clinical remission (odds ratio 3.8, 95% confidence interval 1.1-12.9, P = 0.033).

CONCLUSIONS

Patients with UC showed endoscopic alterations in PPs on NBI-ME, and highly altered appearance of PPs can be associated with a high risk of clinical relapse in patients with UC.

Propionic Acid Promotes the Virulent Phenotype of Crohn's Disease-Associated Adherent-Invasive Escherichia coli

Propionic acid (PA) is a bacterium-derived intestinal antimicrobial and immune modulator used widely in food production and agriculture. Passage of Crohn's disease-associated adherent-invasive Escherichia coli (AIEC) through a murine model, in which intestinal PA levels are increased to mimic the human intestine, leads to the recovery of AIEC with significantly increased virulence. Similar phenotypic changes are observed outside the murine model when AIEC is grown in culture with PA as the sole carbon source; such PA exposure also results in AIEC that persists at 20-fold higher levels in vivo. RNA sequencing identifies an upregulation of genes involved in biofilm formation, stress response, metabolism, membrane integrity, and alternative carbon source utilization. PA exposure also increases virulence in a number of E. coli isolates from Crohn's disease patients. Removal of PA is sufficient to reverse these phenotypic changes. Our data indicate that exposure to PA results in AIEC resistance and increased virulence in its presence.

Therapeutic applications of lytic phages in human medicine

The emergence and spread of antibiotic-resistant bacteria constitute a critical issue for modern medicine. Patients with antibiotic-resistant bacterial infections consume more healthcare resources and have worse clinical outcomes than patients with antibiotic-sensitive bacterial infections. Phages are natural predators of bacteria and may therefore be a source of useful antibacterial drugs. Phage therapy possess availability for oral administration, penetration through the bacteria cell wall, and eradication bacterial biofilms. All of these advantages give phage therapy the possibility to turn into applications for infectious diseases. In this mini-review, we focus on the brief history of lytic phage therapy, the life cycles of lytic phages and the therapeutic effects of lytic phages.

Cows Get Crohn's Disease and They're Giving Us Diabetes

Increasingly, Johne's disease of ruminants and human Crohn's disease are regarded as the same infectious disease: paratuberculosis. Mycobacterium avium ss. paratuberculosis (MAP) is the cause of Johne's and is the most commonly linked infectious cause of Crohn's disease. Humans are broadly exposed to MAP in dairy products and in the environment. MAP has been found within granulomas such as Crohn's disease and can stimulate autoantibodies in diseases such as type 1 diabetes (T1D) and Hashimoto's thyroiditis. Moreover, beyond Crohn's and T1D, MAP is increasingly associated with a host of autoimmune diseases. This article suggests near equivalency between paucibacillary Johne's disease of ruminant animals and human Crohn's disease and implicates MAP zoonosis beyond Crohn's disease to include T1D.

Alteration of Gut Microbiota in Inflammatory Bowel Disease (IBD): Cause or Consequence? IBD Treatment Targeting the Gut Microbiome

Inflammatory bowel disease (IBD) is a chronic complex inflammatory gut pathological condition, examples of which include Crohn’s disease (CD) and ulcerative colitis (UC), which is associated with significant morbidity. Although the etiology of IBD is unknown, gut microbiota alteration (dysbiosis) is considered a novel factor involved in the pathogenesis of IBD. The gut microbiota acts as a metabolic organ and contributes to human health by performing various physiological functions; deviation in the gut flora composition is involved in various disease pathologies, including IBD. This review aims to summarize the current knowledge of gut microbiota alteration in IBD and how this contributes to intestinal inflammation, as well as explore the potential role of gut microbiota-based treatment approaches for the prevention and treatment of IBD. The current literature has clearly demonstrated a perturbation of the gut microbiota in IBD patients and mice colitis models, but a clear causal link of cause and effect has not yet been presented. In addition, gut microbiota-based therapeutic approaches have also shown good evidence of their effects in the amelioration of colitis in animal models (mice) and IBD patients, which indicates that gut flora might be a new promising therapeutic target for the treatment of IBD. However, insufficient data and confusing results from previous studies have led to a failure to define a core microbiome associated with IBD and the hidden mechanism of pathogenesis, which suggests that well-designed randomized control trials and mouse models are required for further research. In addition, a better understanding of this ecosystem will also determine the role of prebiotics and probiotics as therapeutic agents in the management of IBD.

Painful neurotrophins and their role in visceral pain

Beyond their well-known role in embryonic development of the central and peripheral nervous system, neurotrophins, particularly nerve growth factor and brain-derived neurotrophic factor, exert an essential role in pain production and sensitization. This has mainly been studied within the framework of somatic pain, and even antibodies (tanezumab and fasinumab) have recently been developed for their use in chronic somatic painful conditions, such as osteoarthritis or low back pain. However, data suggest that neurotrophins also exert an important role in the occurrence of visceral pain and visceral sensitization. Visceral pain is a distressing symptom that prompts many consultations and is typically encountered in both 'organic' (generally inflammatory) and 'functional' (displaying no obvious structural changes in routine clinical evaluations) disorders of the gut, such as inflammatory bowel disease and irritable bowel syndrome, respectively. The present review provides a summary of neurotrophins as a molecular family and their role in pain in general and addresses recent investigations of the involvement of nerve growth factor and brain-derived neurotrophic factor in visceral pain, particularly that associated with inflammatory bowel disease and irritable bowel syndrome.

Combined Nutraceuticals: A Novel Approach to Colitis-Associated Colorectal Cancer?

Ulcerative colitis is an unremitting and lifelong inflammatory bowel disease that is increasing in prevalence worldwide. Patients display various clinical symptoms such as abdominal pain, diarrhea and fatigue. The etiology of ulcerative colitis remains unknown and the current pharmaceutical treatments are variably effective and not curative, highlighting the need for improved therapeutic approaches. Furthermore, patients with ulcerative colitis are at an increased risk of developing colorectal cancer. Some naturally sourced agents, named nutraceuticals, have been identified to possess anti-inflammatory and antioxidant properties. Of particular interest is Emu Oil, grape seed extract and Japanese Kampo medicine. Previously, Emu Oil has protected and repaired intestinal damage in models of gastrointestinal diseases including colitis and colitis-associated colorectal cancer. Additionally, grape seed extract possesses anticancer properties in vitro. Moreover, Kampo medicine, composed of herbal ingredients, is widely used in Japan for the treatment of various medical conditions and has demonstrated efficacy in targeting cancer cells in vitro. Nutraceuticals in combination have not yet been widely investigated in a setting of colitis-associated colorectal cancer. Investigation into the efficacy of Emu Oil combined with other nutraceuticals, including grape seed extract and Kampo medicine, is warranted as they may provide a novel approach to conventional colitis and colorectal cancer management.

Giardia Infection of the Small Intestine Induces Chronic Colitis in Genetically Susceptible Hosts

The lumen-dwelling protozoan Giardia is an important parasitic cause of diarrheal disease worldwide. Infection can persist over extended periods with minimal intestinal inflammation, suggesting that Giardia may attenuate host responses to ensure its survival, although clearance eventually occurs in most cases. IL-10 is an anti-inflammatory regulator critical for intestinal homeostasis and controlling host responses to bacterial exposure, yet its potential role in coordinating antiprotozoal host defense in the intestine is not known. In this study, we found that murine infection with the natural enteric pathogen Giardia muris induced a transient IL-10 response after 2-4 wk at the primary site of infection in the upper small intestine, but parasite colonization and eradication were not affected by the absence of the cytokine in gene-targeted mice. However, IL-10 was critical for controlling infection-associated immunological sequelae in the colon because severe and persistent diarrhea and colitis were observed in IL-10-deficient mice within 1-2 wk postinfection but not in uninfected littermate controls. Inflammation was characterized by epithelial hyperplasia, neutrophil and macrophage expansion, and Th1 induction and could be prevented by blockade of IL-12/IL-23 p40 but not depletion of CD11c+ dendritic cells. Furthermore, the intestinal microbiota underwent characteristic shifts in composition and was required for disease because antibiotics and loss of TLR signaling in MyD88-deficient mice protected against colitis. Together, our data suggest that transient infection by a luminal and seemingly noninflammatory pathogen can trigger sustained colitis in genetically susceptible hosts, which has broader implications for understanding postinfectious syndromes and other chronic intestinal inflammatory conditions.

Combined Infection of Human Herpes Viruses: A Risk Factor for Subsequent Colectomy in Ulcerative Colitis

BACKGROUND

Little is known about the prevalence and pathogenicity of human herpes viruses except for cytomegalovirus (CMV) in patients with inflammatory bowel disease (IBD). The aim of this study was to determine the prevalence of human herpes viruses on colonic mucosa in patients with IBD and assess the long-term outcomes in these patients.

METHODS

We examined the colonic mucosal specimens from 66 patients with ulcerative colitis (UC), 54 patients with Crohn's disease (CD), and 29 healthy patients to identify the 6 most common types of human herpes virus, using multiplex polymerase chain reaction (PCR) technique.

RESULTS

Herpes simplex virus (HSV)-1/2 and varicella-zoster virus (VZV) were not detected in any of the groups. There was a higher prevalence of Epstein-Barr virus (EBV) (21.2%) and CMV (15.1%) in patients with UC than in patients with CD (EBV 9.3%, CMV 0%) and patents in the healthy control group (EBV 0%, CMV 3.4%). The prevalence of human herpes virus (HHV)-6A/B and HHV-7 was not statistically different among the groups. Five UC patients with inflammation had coexisting CMV and EBV or HHV-6. The combined infection of CMV with EBV or HHV-6 was a significant and independent prognostic factor for subsequent colectomy in patients with UC.

CONCLUSIONS

The increased prevalence of CMV coexisting with EBV/HHV-6 infection was associated with the clinical course in patients with UC. 10.1093/ibd/izy005_video1izy005_Video_15786489376001.

Bacteriocins and bacteriophage; a narrow-minded approach to food and gut microbiology

Bacteriocins and bacteriophage (phage) are biological tools which exhibit targeted microbial killing, a phenomenon which until recently was seen as a major drawback for their use as antimicrobial agents. However, in an age when the deleterious consequences of broad-spectrum antibiotics on human health have become apparent, there is an urgent need to develop narrow-spectrum substitutes. Indeed, disruption of the microbial communities which exist on and in our bodies can generate immediate and long-term negative effects and this is particularly borne out in the gut microbiota community whose disruption has been linked to a number of disorders reaching as far as the brain. Moreover, the antibiotic resistance crisis has resulted in our inability to treat many bacterial infections and has triggered the search for damage-limiting alternatives. As bacteriocins and phage are natural entities they are relatively easy to isolate and characterise and are also ideal candidates for improving food safety and quality, forfeiting the need for largely unpopular chemical preservatives. This review highlights the efficacy of both antimicrobial agents in terms of gut health and food safety and explores the body of scientific evidence supporting their effectiveness in both environments.

Neonatal Colonic Inflammation Epigenetically Aggravates Epithelial Inflammatory Responses to Injury in Adult Life

BACKGROUND & AIMS

Early life adversity is considered a risk factor for the development of gastrointestinal diseases, including inflammatory bowel disease. We hypothesized that early life colonic inflammation causes susceptibility to aggravated overexpression of interleukin (IL)1β.

METHODS

We developed a 2-hit rat model in which neonatal inflammation (NI) and adult inflammation (AI) were induced by trinitrobenzene sulfonic acid.

RESULTS

Aggravated immune responses were observed in NI + AI rats, including a sustained up-regulation of IL1β and other cytokines. In parallel with exacerbated loss of inhibitor of kappa B alpha expression, NI + AI rats showed hyperacetylation of histone H4K12 and increased V-Rel Avian Reticuloendotheliosis Viral Oncogene Homolog A binding on the IL1B promoter, accompanied by high levels of norepinephrine/epinephrine. Propranolol, a β-blocker, markedly ameliorated the inflammatory response and IL1β overexpression by mitigating against epigenetic modifications. Adrenalectomy abrogated NI-induced disease susceptibility whereas yohimbine sensitized the epithelium for exacerbated immune response. The macrophages of NI rats produced more IL1β than controls after exposure to lipopolysaccharide (LPS), suggesting hypersensitization; incubation with LPS plus Foradil (Sigma, St. Louis, MO), a β2-agonist, induced a greater IL1β expression than LPS alone. Epinephrine and Foradil also exacerbated LPS-induced IL1β activation in human THP-1-derived macrophages, by increasing acetylated H4K12, and these increases were abrogated by propranolol.

CONCLUSIONS

NI sensitizes the colon epithelium for exacerbated IL1β activation by increasing stress hormones that induce histone hyperacetylation, allowing greater access of nuclear factor-κB to the IL1B promoter and rendering the host susceptible to aggravated immune responses. Our findings suggest that β blockers have a therapeutic potential for inflammatory bowel disease susceptibility and establish a novel paradigm whereby NI induces epigenetic susceptibility to inflammatory bowel disease.

Total glucosides of paeony ameliorates TNBS‑induced colitis by modulating differentiation of Th17/Treg cells and the secretion of cytokines

The imbalance between effector CD4+ T helper 17 (Th17) and regulatory CD4+ T cells (Treg) cells and their associated cytokines, have been associated with the pathogenesis of inflammatory bowel disease (IBD). Total glycosides of paeony (TGP) is an alternative immunomodulatory agent that is widely used for the treatment of autoimmune diseases. The present study aimed to evaluate the modulatory effect of TGP in a rat model of colitis induced by 2,4,6‑trinitrobenzene sulfonic acid (TNBS). TGP was administered intragastrically 24 h after the TNBS intrarectal instillation for 7 days. TGP treatment ameliorated the clinical status and reversed the histopathologic severity of acute TNBS colitis. Furthermore, TGP inhibited the levels of Th17‑associated cytokines interleukin (IL)‑17, IL‑6, tumor necrosis factor‑α, whereas the expression levels of Treg‑associated cytokines IL‑10, transforming growth factor‑β in the plasma, colon, spleen and mesenteric lymph nodes (MLN). Additionally, TGP reduced the percentage of Th17 cells; however, the proportion of Treg cells in the spleen and MLN was increased. The present study also observed a suppression of Th17‑associated transcription factor, termed retinoid‑related orphan receptor‑γt (ROR‑γt). However, expression of the Treg‑associated transcription factor forkhead boxp3 was increased in the TGP treatment group. Therefore, the present findings suggest that TGP has a regulatory role in modulating the balance of Th17 and Treg cells to ameliorate the TNBS‑induced colitis and support the strategy of using TGP to treat IBD.

Neonatal immune challenge followed by adult immune challenge induces epigenetic-susceptibility to aggravated visceral hypersensitivity

BACKGROUND

Abdominal pain is one of the major symptoms of inflammatory Bowel Disease (IBD). The inflammatory mediators released by colon inflammation are known to sensitize the afferent neurons, which is one of the contributors to abdominal pain. However, not all IBD patients have abdominal pain, and some patients report abdominal pain during remission, suggesting contributions of other pathological factors to abdominal pain in IBD. Epidemiological studies found early-life gastrointestinal infections a risk factor for IBD symptoms and adult-life gastrointestinal infections may trigger the onset of IBD. We investigated the hypothesis that neonatal colon immune challenge followed by an adult colon immune challenge upregulates spinal cord BDNF that aggravates visceral sensitivity over and above that induced by adult colon immune challenge alone.

METHODS

We induced neonatal and adult colon immune challenges by intraluminal administration of trinitrobenzene sulfonic acid to the rat colon.

KEY RESULTS

We found that neonatal immune challenge triggers epigenetic programming that upregulates tyrosine hydroxylase in the locus ceruleus when these rats are subjected to an adult colon immune challenge. The upregulation of locus ceruleus tyrosine hydroxylase, upregulates norepinephrine in the cerebrospinal fluid that acts on adrenergic receptors to enhance pCREB binding to the cAMP response element, which recruits histone acetylene transferase (HAT) to the BDNF gene to enhance its transcription resulting in aggravated visceromotor response to colorectal distension. HAT and adrenergic receptor antagonists block the aggravation of visceral sensitivity.

CONCLUSION & INFERENCES

HAT and adrenergic receptor inhibitors may serve as alternates to opioids and NSAIDS in suppressing abdominal pain in IBD.

Interactions between Intestinal Microbiota and Host Immune Response in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract. Although the etiology and pathogenesis of IBD remain unclear, both genetic susceptibility and environmental factors are implicated in the initiation and progression of IBD. Recent studies with experimental animal models and clinical patients indicated that the intestinal microbiota is one of the critical environmental factors that influence nutrient metabolism, immune responses, and the health of the host in various intestinal diseases, including ulcerative colitis and Crohn’s disease. The objective of this review is to highlight the crosstalk between gut microbiota and host immune response and the contribution of this interaction to the pathogenesis of IBD. In addition, potential therapeutic strategies targeting the intestinal micro-ecosystem in IBD are discussed.

Sex Differences in the Effect of Resveratrol on DSS-Induced Colitis in Mice

Resveratrol is a natural polyphenol studied for its possible protective properties in inflammatory bowel diseases. Moreover, it has been shown to interact with estrogen receptors. In the present study, we aimed to investigate possible diverse effects of resveratrol on female and male mice in DSS-induced colitis. Thirty-seven C57BL/6 mice (21 female and 16 male) were divided into three groups for each sex. The first group received pure water (CTRL). The other two groups received 1.5% dextran sulfate sodium (DSS) to induce colitis from which one group was treated with resveratrol (DSS + RSV). Intake of 1.5% DSS caused weight loss in all DSS groups compared to control mice. Weight loss, stool consistency, and discomfort did not show any protective effect of resveratrol in males and showed even adverse effects in females. In females, the activity of myeloperoxidase was lower compared to that in males. However, colon length and spleen weight showed no sex differences, which can indicate the induction of only mild colitis in mice. Resveratrol did not have any effect on TNF-alpha levels. Taken together, these results for the first time propose possible diverse effects of resveratrol in DSS-induced colitis model depending on the sex of the animal. However, this conclusion must be confirmed by further analyses.

The Intestinal Microbiota in Inflammatory Bowel Disease

The intestinal microbiota has important metabolic and host-protective functions. Conversely to these beneficial functions, the intestinal microbiota is thought to play a central role in the etiopathogenesis of inflammatory bowel disease (IBD; Crohn's disease and ulcerative colitis), a chronic inflammation of the gut mucosa. Genetic screens and studies in experimental mouse models have clearly demonstrated that IBD can develop due to excessive translocation of bacteria into the bowel wall or dysregulated handling of bacteria in genetically susceptible hosts. In healthy individuals, the microbiota is efficiently separated from the mucosal immune system of the gut by the gut barrier, a single layer of highly specialized epithelial cells, some of which are equipped with innate immune functions to prevent or control access of bacterial antigens to the mucosal immune cells. It is currently unclear whether the composition of the microbial flora or individual bacterial strains or pathogens induces or supports the pathogenesis of IBD. Further research will be necessary to carefully dissect the contribution of individual bacterial species to this disease and to ascertain whether specific modulation of the intestinal microbiome may represent a valuable further option for future therapeutic strategies.

Microbiome, Metabolome and Inflammatory Bowel Disease

Inflammatory Bowel Disease (IBD) is a multifactorial disorder that conceptually occurs as a result of altered immune responses to commensal and/or pathogenic gut microbes in individuals most susceptible to the disease. During Crohn’s Disease (CD) or Ulcerative Colitis (UC), two components of the human IBD, distinct stages define the disease onset, severity, progression and remission. Epigenetic, environmental (microbiome, metabolome) and nutritional factors are important in IBD pathogenesis. While the dysbiotic microbiota has been proposed to play a role in disease pathogenesis, the data on IBD and diet are still less convincing. Nonetheless, studies are ongoing to examine the effect of pre/probiotics and/or FODMAP reduced diets on both the gut microbiome and its metabolome in an effort to define the healthy diet in patients with IBD. Knowledge of a unique metabolomic fingerprint in IBD could be useful for diagnosis, treatment and detection of disease pathogenesis.

Cultured enterocytes internalise bacteria across their basolateral surface for, pathogen-inhibitable, trafficking to the apical compartment

In vitro- and in vivo-polarised absorptive epithelia (enterocytes) are considered to be non-phagocytic towards bacteria with invasive pathogenic strains relying on virulence factors to 'force' entry. Here, we report a serendipitous discovery that questions these beliefs. Thus, we uncover in well-established models of human small (Caco-2; TC-7) and large (T84) intestinal enterocytes a polarization-dependent mechanism that can transfer millions of bacteria from the basal to apical compartment. Antibiotic-protection assays, confocal imaging and drug inhibitor data are consistent with a transcellular route in which internalized, basolateral-membrane enclosed bacteria are trafficked to and across the apical surface. Basal-to-apical transport of non-pathogenic bacteria (and inert beads) challenged the idea of pathogens relying on virulence factors to force entry. Indeed, studies with Salmonella demonstrated that it's entry-forcing virulence factor (SPI-I) was not required to enter via the basolateral surface but to promote another virulence-associated event (intra-enterocyte accumulation).

Cytokine profile in children with inflammatory bowel disease

Crohn's disease (CD) and ulcerative colitis (UC) are inflammatory bowel diseases (IBD) characterized by immune reactivity against microbial and auto-antigens. This work was designed to study the cytokine profile in blood serum and coproextracts of children with CD and UC. The studied patients consisted of 17 children with CD (group I), 17 children with UC (group II), and 18 controls with intestinal dysbiosis (group III). The diagnosis of UC and CD was based on accepted clinical and endoscopic criteria. The levels of 13 cytokines (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, IL-17A, TNF-α, TGF-β, and IFN-γ) were determined in blood sera and coproextracts of the patients and controls using the BioPlex technology. The level of IL-17A was significantly increased and that of TGF-β was significantly decreased in the blood serum of the patients with IBDs. Changes in the cytokine profile in the coproextracts affected the wider spectrum of cytokines. The levels of proinflammatory cytokines (IL-2, IL-4, IL-6, IL-12p70, TNF-α, and IFN-γ) were increased 6-9-fold, whereas the level of the anti-inflammatory cytokine IL-10 was increased 3-fold. The cytokine balance was shifted to the proinflammatory cytokines. The TGF-β level was increased 9-fold and that of IL-17A was increased 3-fold. Thus, the cytokine profile in the coproextracts was more informative than that of the blood serum. The determination of cytokines in coproextracts is simple and noninvasive.

Type I interferons for induction of remission in ulcerative colitis

BACKGROUND

Interferons (IFNs) are cytokines which possess immunoregulatory properties and have been used to successfully treat a number of chronic inflammatory disorders. It has been postulated that Type I IFNs may be able to re-establish the Th1/Th2 balance in Th2 predominant diseases like ulcerative colitis.

OBJECTIVES

To systematically evaluate the efficacy and safety of type I IFN therapy for induction of remission in ulcerative colitis.

SEARCH METHODS

We searched MEDLINE, EMBASE, CENTRAL, the Cochrane IBD/FBD group specialised register, and ClinicalTrials.gov from inception to August 8, 2014. Reference lists of trials and review articles, as well as recent proceedings from major gastroenterology meetings were manually searched.

SELECTION CRITERIA

Randomised controlled trials of type I IFNs for induction of remission in UC were included. The study population included patients of any age with active ulcerative colitis. There were no exclusions based on type, dose or duration of IFN treatment.

DATA COLLECTION AND ANALYSIS

Two independent authors reviewed studies for eligibility, extracted the data and assessed study quality using the Cochrane risk of bias tool. The overall quality of the evidence supporting the outcomes was evaluated using the GRADE criteria. The primary outcome was induction of remission of ulcerative colitis. Secondary outcomes included: time to remission, mean change in disease activity index score, clinical, histological or endoscopic improvement, improvement in quality of life, and adverse events. We calculated the risk ratio (RR) and corresponding 95% confidence interval (CI) for dichotomous outcomes. We calculated the mean difference and corresponding 95% confidence interval for continuous outcomes. Meta-analysis was performed using RevMan 5.3.5 software.

MAIN RESULTS

Six studies were eligible for inclusion (517 patients). Five studies compared type I IFNs to placebo injections (485 patients) and a single study compared IFNs to prednisolone enemas in patients with left-sided colitis (32 patients). The active comparator study was rated as high risk of bias due to an open-label design. Three studies were rated as unclear risk of bias for random sequence generation and allocation concealment. Two studies described as double blind were rated as unclear risk of bias for blinding. There was no significant benefit of type I IFNs over placebo for inducing clinical remission or improvement in patients with active ulcerative colitis. Thirty-six per cent (87/242) of patients in the type I IFNs group achieved clinical remission by 8 to 12 weeks compared to 30% (36/120) of placebo patients (RR 1.16, 95% CI 0.84 to 1.58; 4 studies, 362 patients). A GRADE analysis indicated that the overall quality of the evidence supporting the outcome clinical remission was moderate due to sparse data (123 events). Fifty-six per cent (149/264) of patients in the type I IFNs group improved clinically by 8 to 12 weeks compared to 48% (77/161) of placebo patients (RR 1.16, 95% CI 0.96 to 1.40; 4 studies, 425 patients). A GRADE analysis indicated that the overall quality of the evidence supporting the outcome clinical improvement was moderate due to sparse data (226 events). Patients who received type I IFNs were significantly more likely to withdraw from the studies due to adverse events than those who received placebo. Seven per cent (18/42) of type I IFNs patients withdrew due to adverse events compared to 2% (3/152) of placebo patients (RR 3.16, 95% CI 1.06 to 9.40). A GRADE analysis indicated that the overall quality of the evidence supporting the outcome withdrawal due to adverse events was low due to very sparse data (21 events). The study comparing type I IFNs to prednisolone enemas found no difference between the treatment groups in quality of life or disease activity scores. Common adverse events included headaches, arthralgias, myalgias, fatigue, back pain, nausea, application site reactions, rigors, and fevers. There were no statistically significant differences in the other secondary outcomes.

AUTHORS' CONCLUSIONS

Moderate quality evidence suggests that type I IFNs are not effective for the induction of remission in UC. In addition, there are concerns regarding the tolerability of this class of treatment.

Depletion of enteroantigen-activated CD4⁺ T cells: effects on proliferation and pathogenicity

Naive CD4(+) T cells depleted of natural Treg (CD25(+)) cells proliferate extensively when exposed to a fecal extract [enteroantigen (eAg)] pulsed on antigen-presenting cells (APC). When transplanted into SCID recipient mice, the CD25-depleted T cells induce a chronic colitis with a lethal course. We observed here that if T cells, pre-activated for 48h by eAg from BALB/c or SCID mice, are removed and then reexposed to either of the two sources of antigen, these T cells have completely lost their anti-eAg proliferative capacity in vitro. This observation indicates that eAgs derived from Balb/c and SCID mice are recognized by similar subsets of T cells. However, when transferred into SCID mice, eAg-activation-depleted T cells are still capable of inducing a severe colitis fully comparable with the disease induced by naive CD4(+) T cells.

Contribution of the IL-17/IL-23 axis to the pathogenesis of inflammatory bowel disease

Inflammatory bowel diseases (IBDs) are chronic disorders of modern society, requiring management strategies aimed at prolonging an active life and establishing the exact etiology and pathogenesis. These idiopathic diseases have environmental, genetic, immunologic, inflammatory, and oxidative stress components. On the one hand, recent advances have shown that abnormal immune reactions against the microorganisms of the intestinal flora are responsible for the inflammation in genetically susceptible individuals. On the other hand, in addition to T helper cell-type (Th) 1 and Th2 immune responses, other subsets of T cells, namely regulatory T cells and Th17 maintained by IL-23 are likely to develop IBD. IL-23 acts on innate immune system members and also facilitates the expansion and maintenance of Th17 cells. The IL-17/IL-23 axis is relevant in IBD pathogenesis both in human and experimental studies. Novel biomarkers of IBD could be calprotectin, microRNAs, and serum proinflammatory cytokines. An efficient strategy for IBD therapy is represented by the combination of IL-17A and IL-17F in acute IL-17A knockout TNBS-induced colitis, and also definite decrease of the inflammatory process in IL-17F knockout, DSS-induced colitis have been observed. Studying the correlation between innate and adaptive immune systems, we hope to obtain a focused review in order to facilitate future approaches aimed at elucidating the immunological mechanisms that control gut inflammation.

Pathogenesis of Crohn’s disease: Bug or no bug

The possibility of an infectious origin in inflammatory bowel disease (IBD) has been postulated since the first description of Crohn’s disease (CD). Many observations implicate bacteria as a trigger for the development of CD: lesions occur in regions with higher bacterial concentrations; aphthous ulcers occur in Peyer’s patches; inflammation resolves when the fecal stream is diverted and is reactivated following reinfusion of bowel contents; severity of the disease is correlated with bacterial density in the mucosa; granulomas can contain bacteria; and susceptible mice raised in germ-free conditions develop inflammation when bacteria are introduced in the 1990’s, several studies sought to establish a relationship with viral infections and the onset of IBD, finally concluding that no direct link had been demonstrated. In the past fifteen years, evidence relating IBD pathogenesis to Mycobacterium avium paratuberculosis, salmonella, campylobacter, etc., has been found. The tendency now under discussion to regard microbiota as the primary catalyst has led to the latest studies on microbiota as pathogens, focusing on Escherichia coli, mainly in ileal CD. The present review discusses the literature available on these “bugs”.

RNA-seq analysis reveals significant transcriptome changes in turbot (Scophthalmus maximus) suffering severe enteromyxosis

Background

Enteromyxosis caused by the intestinal myxozoan parasite Enteromyxum scophthalmi is a serious threat for turbot (Scophthalmus maximus, L.) aquaculture, causing severe catarrhal enteritis leading to a cachectic syndrome, with no therapeutic options available. There are still many aspects of host-parasite interaction and disease pathogenesis that are yet to be elucidated, and to date, no analysis of the transcriptomic changes induced by E. scophthalmi in turbot organs has been conducted. In this study, RNA-seq technology was applied to head kidney, spleen and pyloric caeca of severely infected turbot with the aim of furthering our understanding of the pathogenetic mechanisms and turbot immune response against enteromyxosis.

Results

A huge amount of information was generated with more than 23,000 identified genes in the three organs, amongst which 4,762 were differently expressed (DE) between infected and control fish. Associate gene functions were studied based on gene ontology terms and available literature, and the most interesting DE genes were classified into five categories: 1) immune and defence response; 2) apoptosis and cell proliferation; 3) iron metabolism and erythropoiesis; 4) cytoskeleton and extracellular matrix and 5) metabolism and digestive function. The analysis of down-regulated genes of the first category revealed evidences of a connexion failure between innate and adaptive immune response, especially represented by a high number of DE interferon-related genes in the three organs. Furthermore, we found an intense activation of local immune response at intestinal level that appeared exacerbated, whereas in kidney and spleen genes involved in adaptive immune response were mainly down-regulated. The apoptotic machinery was only clearly activated in pyloric caeca, while kidney and spleen showed a marked depression of genes related to erythropoiesis, probably related to disorders in iron homeostasis. The genetic signature of the causes and consequences of cachexia was also demonstrated by the down-regulation of the genes encoding structural proteins and those involved in the digestive metabolism.

Conclusions

This transcriptomic study has enabled us to gain a better understanding of the pathogenesis of enteromyxosis and identify a large number of DE target genes that bring us closer to the development of strategies designed to effectively combat this pathogen.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-1149) contains supplementary material, which is available to authorized users.

The fungal microbiota of de-novo paediatric inflammatory bowel disease

Inflammatory bowel disease (IBD) is characterised by an inappropriate chronic immune response against resident gut microbes. This may be on account of distinct changes in the gut microbiota termed as dysbiosis. The role of fungi in this altered luminal environment has been scarcely reported. We studied the fungal microbiome in de-novo paediatric IBD patients utilising next generation sequencing and compared with adult disease and normal controls. We report a distinct difference in fungal species with Ascomycota predominating in control subjects compared to Basidiomycota dominance in children with IBD, which could be as a result of altered tolerance in these patients.

Immunopathogenesis of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a group of idiopathic, chronic and relapsing inflammatory conditions of the gastrointestinal tract. Familial and epidemiological studies have stressed the involvement of genetic factors and have also shown the critical role of environmental factors such as sanitation and hygiene in the development of IBD. However, the molecular mechanisms of intestinal inflammation in IBD have long remained unknown. In recent years, the study of susceptibility genes involved in the detection of bacterial components and in the regulation of the host immune response has shed light onto the potential role of intestinal pathogens and gut flora in IBD immunobiology. This review presents current knowledge on intestinal epithelial barrier alterations and on dysfunction of mucosal innate and acquired immune responses in IBD. The data support the etiological hypothesis which argues that pathogenic intestinal bacteria and/or infectious agents initiate and perpetuate the inflammation of the gut through disruption of tolerance towards the commensal microbiota in an individual with genetic vulnerability.

Cesarean delivery and risk of inflammatory bowel disease: a systematic review and meta-analysis

OBJECTIVE

It has been considered that cesarean delivery is a risk factor for the two subtypes of inflammatory bowel diseases (IBDs): Crohn's disease (CD) and ulcerative colitis (UC). The aim of this meta-analysis was to examine the relationship between cesarean delivery and the development of IBD.

MATERIAL AND METHODS

We searched the articles retrieved by PubMed, MEDLINE and EMBASE databases to identify observational studies regarding the relationship between cesarean section and the development of CD and/or UC. Pooled odds ratios were calculated for each relationship.

RESULTS

Nine studies evaluated the potential association between cesarean delivery and the development of IBD and met all of our inclusion criteria. The pooled data from six included studies indicated cesarean delivery was a risk factor for CD (95% confidence interval [CI]: 1.12-1.70; p = 0.003). Likewise, we observed a positive association between cesarean delivery and pediatric CD (95% CI: 1.06-1.35; p = 0.005). However, results from the four included studies for UC indicated the rate of cesarean section in UC patients was not higher than that of control subjects (95% CI: 0.87-1.32; p = 0.54). Overall, we did not observe a positive relationship between cesarean delivery and IBD (95% CI: 0.99-1.30; p = 0.08).

CONCLUSION

Results of this meta-analysis support the hypothesis that cesarean delivery was associated with the risk of CD but not of UC. The total rate of cesarean delivery of IBD patients was similar with that of control subjects.

Cytokine networking of innate immunity cells: a potential target of therapy

Innate immune cells, particularly macrophages and epithelial cells, play a key role in multiple layers of immune responses. Alarmins and pro-inflammatory cytokines from the IL (interleukin)-1 and TNF (tumour necrosis factor) families initiate the cascade of events by inducing chemokine release from bystander cells and by the up-regulation of adhesion molecules required for transendothelial trafficking of immune cells. Furthermore, innate cytokines produced by dendritic cells, macrophages, epithelial cells and innate lymphoid cells seem to play a critical role in polarization of helper T-cell cytokine profiles into specific subsets of Th1/Th2/Th17 effector cells or regulatory T-cells. Lastly, the innate immune system down-regulates effector mechanisms and restores homoeostasis in injured tissue via cytokines from the IL-10 and TGF (transforming growth factor) families mainly released from macrophages, preferentially the M2 subset, which have a capacity to induce regulatory T-cells, inhibit the production of pro-inflammatory cytokines and induce healing of the tissue by regulating extracellular matrix protein deposition and angiogenesis. Cytokines produced by innate immune cells represent an attractive target for therapeutic intervention, and multiple molecules are currently being tested clinically in patients with inflammatory bowel disease, rheumatoid arthritis, systemic diseases, autoinflammatory syndromes, fibrosing processes or malignancies. In addition to the already widely used blockers of TNFα and the tested inhibitors of IL-1 and IL-6, multiple therapeutic molecules are currently in clinical trials targeting TNF-related molecules [APRIL (a proliferation-inducing ligand) and BAFF (B-cell-activating factor belonging to the TNF family)], chemokine receptors, IL-17, TGFβ and other cytokines.

Escherichia coli isolates from inflammatory bowel diseases patients survive in macrophages and activate NLRP3 inflammasome

Crohn's disease (CD) is a multifactorial pathology associated with the presence of adherent-invasive Escherichia coli (AIEC) and NLRP3 polymorphic variants. The presence of intracellular E. coli in other intestinal pathologies (OIP) and the role of NLRP3-inflammasome in the immune response activated by these bacteria have not been investigated. In this study, we sought to characterize intracellular strains isolated from patients with CD, ulcerative colitis (UC) and OIP, and analyze NLRP3-inflammasome role in the immune response and bactericidal activity induced in macrophages exposed to invasive bacteria. For this, intracellular E. coli isolation from ileal biopsies, using gentamicin-protection assay, revealed a prevalence and CFU/biopsy of E. coli higher in biopsies from CD, UC and OIP patients than in controls. To characterize bacterial isolates, pulsed-field gel electrophoresis (PFGE) patterns, virulence genes, serogroup and phylogenetic group were analyzed. We found out that bacteria isolated from a given patient were closely related and shared virulence factors; however, strains from different patients were genetically heterogeneous. AIEC characteristics in isolated strains, such as invasive and replicative properties, were assessed in epithelial cells and macrophages, respectively. Some strains from CD and UC demonstrated AIEC properties, but not strains from OIP. Furthermore, the role of NLRP3 in pro-inflammatory cytokines production and bacterial elimination was determined in macrophages. E. coli strains induced IL-1β through NLRP3-dependent mechanism; however, their elimination by macrophages was independent of NLRP3. Invasiveness of intracellular E. coli strains into the intestinal mucosa and IL-1β production may contribute to CD and UC pathogenesis.

Role of the gut microbiota in inflammatory bowel disease pathogenesis: What have we learnt in the past 10 years?

Our understanding of the microbial involvement in inflammatory bowel disease (IBD) pathogenesis has increased exponentially over the past decade. The development of newer molecular tools for the global assessment of the gut microbiome and the identification of nucleotide-binding oligomerization domain-containing protein 2 in 2001 and other susceptibility genes for Crohn’s disease in particular has led to better understanding of the aetiopathogenesis of IBD. The microbial studies have elaborated the normal composition of the gut microbiome and its perturbations in the setting of IBD. This altered microbiome or “dysbiosis” is a key player in the protracted course of inflammation in IBD. Numerous genome-wide association studies have identified further genes involved in gastrointestinal innate immunity (including polymorphisms in genes involved in autophagy: ATG16L1 and IGRM), which have helped elucidate the relationship of the local innate immunity with the adjacent luminal bacteria. These developments have also spurred the search for specific pathogens which may have a role in the metamorphosis of the gut microbiome from a symbiotic entity to a putative pathogenic one. Here we review advances in our understanding of microbial involvement in IBD pathogenesis over the past 10 years and offer insight into how this will shape our therapeutic management of the disease in the coming years.