Globalisation of inflammatory bowel disease: perspectives from the evolution of inflammatory bowel disease in the UK and China

Human-Gut-DNA Virome Variations across Geography, Ethnicity, and Urbanization

The human-gut-DNA virome is highly diverse and individual specific, but little is known of its variation at a population level. Here, we report the fecal DNA virome of 930 healthy adult subjects from two regions in China (Hong Kong and Yunnan) spanning six ethnicities (Han, Zang, Miao, Bai, Dai, and Hani), and including urban and rural residents for each ethnicity. Twenty host factors were found to significantly correlate with the human-gut virome variation, with geography carrying the strongest impact and ethnicity-distinct diets associating with certain viral species. Urbanization enhances interindividual dissimilarities between gut viromes, with the duration of urban residence associating with multiple bacteriophages, including Lactobacillus phage and Lactococcus phage. Overall, the gut virome presents more heterogeneity relative to the bacterial microbiome across the examined Chinese populations. This study highlights population-based variations and the importance of host and environmental factors in shaping the DNA virome in the human gut.

Reappraising Risk Factors for Inflammatory Bowel Disease-associated Neoplasia: Implications for Colonoscopic Surveillance in IBD

One of the most feared complications of inflammatory bowel disease [IBD]-associated colitis is colorectal cancer. When considering the substantial increase in the prevalence of IBD, without any anticipated decline, coupled with decreasing colectomy rates for dysplasia and expanding medical options for effectively controlling inflammation, it is predicted that the pool of people living with-and ageing with-colonic IBD, who are recommended to undergo lifelong colonoscopic surveillance for colorectal neoplasia, will strain existing resources and challenge the sustainability of current guideline-based surveillance recommendations. At the same time, we are missing the opportunity for early detection in a group that is overlooked as high-risk, as a substantial proportion of colorectal cancers are being diagnosed in individuals with colonic IBD who have disease duration shorter than when guidelines recommend surveillance initiation. Here, we reappraise: 1] inflammation as a dynamic risk factor that considers patients' cumulative course; 2] time of screening initiation that is not based primarily on absolute disease duration; and 3] surveillance intervals as an iterative determination based on individual patient factors and consecutive colonoscopic findings. This Viewpoint supports a paradigm shift that will ideally result in a more effective and higher-value colorectal cancer prevention approach in IBD.

Diagnosis and natural history of preclinical and early inflammatory bowel disease

Inflammatory bowel disease is a chronic and progressive disorder of the gastrointestinal tract. A relevant proportion of patients develop complicated lesions, defined as strictures, fistulas and/or abscesses already at diagnosis, and this proportion increases over time. The preclinical phase defines the period of time from the appearance of the first immune disturbances until the development of overt disease, and it may be present months to years before the diagnosis. Multiple biomarkers (e.g., C-reactive protein, interleukin-6, fecal calprotectin) and cellular mechanisms (e.g., complement cascade, lysosomes, innate immunity, and glycosaminoglycan metabolism) are already altered during this period. Research in this area allows the description of the initial immune disturbances that may identify potential targets and lead to the development of new drug therapies. During this period, different interventions in high-risk individuals, including drugs or environmental factors, will open the possibility of innovative strategies focused on the reduction of complications, or even prevention trials for inflammatory bowel disease. Here, we review the most relevant findings regarding the characteristics, prevalence and biomarkers associated with preclinical disease, along with their possible use in our future clinical practice.

Rab27A promotes cellular apoptosis and ROS production by regulating the miRNA-124-3p/STAT3/RelA signalling pathway in ulcerative colitis

Ulcerative colitis (UC) is a multifactorial inflammatory disease, and increasing evidence has demonstrated that the mechanism of UC pathogenesis is associated with excessive cellular apoptosis and reactive oxygen species (ROS) production. However, their function and molecular mechanisms related to UC remain unknown. In this study, Rab27A mRNA and protein were proven to be overexpressed in intestinal epithelial cells of UC patients and DSS‐induced colitis mice, compared with control (P < 0.05). And Rab27A silencing inhibits inflammatory process in DSS‐induced colitis mice (P < 0.05). Then, it was shown that knockdown of Rab27A suppressed apoptosis and ROS production through modulation of miR‐124‐3p, whereas overexpression of Rab27A promoted apoptosis and ROS production in LPS‑induced colonic cells. In addition, enhanced expression of miR‐124‐3p attenuated apoptosis and ROS production by targeting regulation of STAT3 in LPS‑induced colonic cells. Mechanistically, we found Rab27A reduced the expression and activity of miR‐124‐3p to activate STAT3/RelA signalling pathway and promote apoptosis and ROS production in LPS‑induced colonic cells, whereas overexpression of miR‐124‐3p abrogated these effects of Rab27A. More importantly, animal experiments illustrated that ectopic expression of Rab27A promoted the inflammatory process, whereas overexpression of miR‐124‐3p might interfere with the inflammatory effect in DSS‐induced colitis mice. In summary, Rab27A might modulate the miR‐124‐3p/STAT3/RelA axis to promote apoptosis and ROS production in inflammatory colonic cells, suggesting that Rab27A as a novel therapeutic target for the prevention and treatment of UC patients.

Study on the effect of Periplaneta americana on ulcerative colitis in rats induced by 2,4,6-trinitrobenzene sulfonic acid

Ulcerative colitis (UC) is a chronic inflammatory disease of intestinal tract, and Periplaneta americana has been found to be effective in the treatment for UC. The purpose of the study was to investigate the therapeutic effect of Periplaneta americana extract Ento-A on UC in rats induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) and to explore its mechanism. The Sprague-Dawley (SD) rats were randomly divided into normal control group; TNBS-treated group; sulfasalazine (SASP) treated group; Ento-A low- (50 mg/kg), medium- (100 mg/kg), and high-dose (200 mg/kg) groups, respectively. The UC model of rats was induced via TNBS. Disease activity index (DAI) was used to evaluate the severity of UC in rats. The macroscopic and microscopic damages of colon were accessed by colon mucosa damage index (CMDI) and histopathological score (HS), respectively. The levels of interleukin-4 (IL-4), interleukin-17 (IL-17), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) in serum and the contents of myeloperoxidase (MPO), transforming growth factor-β1 (TGF-β1), and epidermal growth factor (EGF) in colonic mucosa were measured by enzyme-linked immunosorbent assay (ELISA). Compared with the normal control group, the TNBS-treated group showed increase in DAI, CMDI, HS, IL-17, TNF-α, IFN-γ as well as MPO and decrease in the levels of IL-4, EGF, and TGF-β1. However, Ento-A-administrated groups reversed the changes in the DAI, CMDI, HS, and the cytokines caused by TNBS. The study indicates that Periplaneta americana extract Ento-A can effectively alleviate the inflammation in TNBS-induced UC of rats, and the mechanism of that may be related to restoring the balance of T helper 1 (Th1)/Th2/Th17/T regulatory (Treg) cytokines.

Modified Sijunzi decoction in the treatment of ulcerative colitis in the remission phase: study protocol for a series of N-of-1 double-blind, randomised controlled trials

Background

Modified Sijunzi decoction (SJZD) has been used to treat ulcerative colitis (UC) in remission. However, more rigorous clinical trials are necessary to evaluate its effectiveness. Therefore, a series of single-case randomised controlled trials (N-of-1 trials) is proposed to compare the efficacy of modified SJZD with mesalazine for treating UC in remission.

Methods

This is a single-site, hospital-based, double-blind N-of-1 trial for 10 single subjects. Three cycles of N-of-1 trials are planned. There are two treatment periods in each cycle. Modified SJZD combined with mesalazine placebo or mesalazine combined with modified SJZD placebo will be randomised during each 8-week treatment period. There is no washout period in the study. Subjects will be selected by the researcher strictly in accordance with the inclusion and exclusion criteria.

Discussion

Paired t tests and mixed-effect models will be used to analyse the visual analogue scale (VAS) for clinical symptoms and the quality of life questionnaire responses. The findings will be interpreted with caution. We anticipate that the results will show that modified SJZD is effective for patients with UC in remission.

Trial registration

Chinese Clinical Trial Register, ID: ChiCTR1900024086. Registered on 24 June 2019.

Revisiting Inflammatory Bowel Disease: Pathology, Treatments, Challenges and Emerging Therapeutics Including Drug Leads from Natural Products

Inflammatory bowel disease (IBD) is a chronic and life-long disease characterized by gastrointestinal tract inflammation. It is caused by the interplay of the host's genetic predisposition and immune responses, and various environmental factors. Despite many treatment options, there is no cure for IBD. The increasing incidence and prevalence of IBD and lack of effective long-term treatment options have resulted in a substantial economic burden to the healthcare system worldwide. Biologics targeting inflammatory cytokines initiated a shift from symptomatic control towards objective treatment goals such as mucosal healing. There are seven monoclonal antibody therapies excluding their biosimilars approved by the US Food and Drug Administration for induction and maintenance of clinical remission in IBD. Adverse side effects associated with almost all currently available drugs, especially biologics, is the main challenge in IBD management. Natural products have significant potential as therapeutic agents with an increasing role in health care. Given that natural products display great structural diversity and are relatively easy to modify chemically, they represent ideal scaffolds upon which to generate novel therapeutics. This review focuses on the pathology, currently available treatment options for IBD and associated challenges, and the roles played by natural products in health care. It discusses these natural products within the current biodiscovery research agenda, including the applications of drug discovery techniques and the search for next-generation drugs to treat a plethora of inflammatory diseases, with a major focus on IBD.

Crohn's disease

Crohn's disease is an inflammatory bowel disease that is characterized by chronic inflammation of any part of the gastrointestinal tract, has a progressive and destructive course and is increasing in incidence worldwide. Several factors have been implicated in the cause of Crohn's disease, including a dysregulated immune system, an altered microbiota, genetic susceptibility and environmental factors, but the cause of the disease remains unknown. The onset of the disease at a young age in most cases necessitates prompt but long-term treatment to prevent disease flares and disease progression with intestinal complications. Thus, earlier, more aggressive treatment with biologic therapies or novel small molecules could profoundly change the natural history of the disease and decrease complications and the need for hospitalization and surgery. Although less invasive biomarkers are in development, diagnosis still relies on endoscopy and histological assessment of biopsy specimens. Crohn's disease is a complex disease, and treatment should be personalized to address the underlying pathogenetic mechanism. In the future, disease management might rely on severity scores that incorporate prognostic factors, bowel damage assessment and non-invasive close monitoring of disease activity to reduce the severity of complications.

Comparative of the Effectiveness and Safety of Biological Agents, Tofacitinib, and Fecal Microbiota Transplantation in Ulcerative Colitis: Systematic Review and Network Meta-Analysis

BACKGROUND

Biological agents are commonly used for the treatment of ulcerative colitis (UC). As new treatments, tofacitinib, and fecal microbiota transplantation (FMT) have demonstrated efficacy in treating UC. This network meta-analysis aims to determine the efficacy and safety of biological agents, tofacitinib, and FMT.

METHODS

A network meta-analysis was conducted by systematically searching the PubMed, Embase, and Cochrane Libraries. According to strict inclusion and exclusion criteria, we included randomized controlled trials (RCTs) of biological agents, tofacitinib, and FMT in UC. A random-effect model was chosen by the network meta-analysis and sensitivity analysis. Heterogeneity test and publication bias test were performed to determine the efficacy of treatments.

RESULTS

Data were extracted from 16 RCTs and we found that all treatments were more effective than the placebos. A total of 21 comparisons were made to determine efficiency. We found that infliximab, vedolizumab, and FMT performed better curative effect in terms of absolute effects and relative ranks. Furthermore, there was no statistical difference in the efficacy of biological agents, tofacitinib, and FMT. Moreover, no treatments were found to increase the occurrence of adverse events when compared with placebos, except infliximab. However, vedolizumab seemed to reduce the occurrence of adverse events compared with infliximab.

CONCLUSION

Of the biological agents, vedolizumab and infliximab were the most effective, suggesting that biological agents are still a better choice. Nevertheless, tofacitinib and FMT may be promising alternatives with high efficacies. However, more safety and maintenance studies need to be conducted in future for the acquisition of more accurate results.Abbreviations: FMT: Fecal microbiota transplantation; UC: Ulcerative colitis; RCTs: Randomized controlled trials; IBD: Inflammatory bowel disease; CD: Crohn's disease; IBS: Irritable bowel syndrome; CDI: Clostridium difficile infections; ITT: Intention-to-treat; RR: Relative risk; CI: Confidence interval; CrI: Credible intervals; IFX: Infliximab; ADA: Adalimumab; TFB: Tofacitinib; GLM: Golimumab; VDZ: Vedolizumab; PBO: Placebo; wk: week; F: Female; M: Male; AEs: Adverse events; SAEs: Serious adverse events; anti-TNF: Anti-tumor necrosis factors.

Progression of Inflammatory Bowel Diseases Throughout Latin America and the Caribbean: A Systematic Review

BACKGROUND & AIMS

The incidence of inflammatory bowel diseases (IBD) is increasing in Latin America. We performed a systematic review to identify clinical and epidemiologic features of IBD in Latin America (including Mexico, Central America, and South America) and the Caribbean.

METHODS

We searched MEDLINE, EMBASE, and SciELO databases for clinical or epidemiologic studies of Crohn's disease (CD) or ulcerative colitis (UC) from Latin American and Caribbean countries and territories that reported incidence, prevalence, ratio of UC:CD, IBD phenotype, and treatment, through September 12, 2018. Data were extracted from 61 articles for analysis.

RESULTS

The incidence and prevalence of IBD have been steadily increasing in Latin America and the Caribbean. The incidence of CD in Brazil increased from 0.08 per 100,000 person-years in 1988 to 0.68 per 100,000 person-years in 1991-1995 to 5.5 per 100,000 person-years in 2015. The highest reported prevalence of IBD was in Argentina, in 2007, at 15 and 82 per 100,000 person-years for CD and UC, respectively. The ratio of UC:CD exceeded 1 in all regions throughout Latin America and the Caribbean with the exception of Brazil. Treatment with tumor necrosis factor antagonists increased steadily for patients with CD (43.4% of all patients in Brazil were treated in 2014) but less so for patients with UC (4.5% of all patients were treated in 2014). Surgery for IBD decreased with time. In Chile, surgeries were performed on 57.0% of patients with CD and 18.0% of patients with UC during the period of 1990-2002; these values decreased to 38.0% and 5.0%, respectively, during the period of 2012-2015. In Peru, 6.9% of patients with UC received colectomies in the period of 2001-2003 and 6.2% in 2004-2014.

CONCLUSIONS

In a systematic review, we found the incidence of IBD to be increasing throughout Latin America and the Caribbean. Population-based epidemiology studies are needed to evaluate the increase in IBD in these regions, which differ from other global regions in climate, culture, demographics, diet, healthcare delivery and infrastructure, and socioeconomic status.

Inflammatory Bowel Disease and Obstructive Pulmonary Disease: A Two-way Association?

Inflammatory bowel diseases (IBD) is an umbrella term that covers both ulcerative colitis (UC) and Crohn's disease (CD), which are chronic inflammatory conditions of the gastrointestinal system. Airway diseases are one of the most commonly studied manifestations of IBD. It is observed that populations with pre-existing obstructive pulmonary conditions are at higher risk of new-onset IBD. This newly documented evidence of increased incidence of IBD among patients with pulmonary diseases and the higher than the estimated prevalence of pulmonary diseases among IBD sufferers support the hypothesis of a two-way association. This review article focuses on summarizing the current knowledge and available evidence regarding the association between IBD and obstructive pulmonary diseases such as chronic obstructive pulmonary disease (COPD), emphysema, bronchiectasis, and asthma.

We utilized PubMed as the primary search source and database and included the free full-text articles available on it, published over the past five years. We reviewed literature from multiple regions of the world, such as the US, UK, China, and Canada and compiled this traditional review article utilizing the information collected from 4,966,459 patients. Specifications such as age and gender were not mentioned in all articles.

This review will serve to strengthen the existing research database concerning the relationship between IBD and obstructive pulmonary diseases. It will help to highlight the significance of the two-way association between IBD and obstructive pulmonary disease and the importance of treating these two conditions simultaneously. It will also raise awareness about the importance of timely detection of IBD and associated airway complications, leading to decreased disease burden and the treatment cost.

Epidemiology and risk factors of colorectal cancer in China

In China, colorectal cancer (CRC) ranked fourth and fifth in the highest incidence and mortality rates of all malignancies in 2018, respectively. Although these rates are below the world average, China placed first worldwide in the number of new CRC cases and CRC-related deaths because of its comparatively large population. This disease represents a threat to the health of population and incurs a heavy economic burden on the society and individuals. CRC has various risk factors, including age, sex, lifestyle, genetic factors, obesity, diabetes, gut microbiota status, and precancerous lesions. Furthermore, incidence and mortality rates of CRC are closely related to socioeconomic development levels, varying according to regional and population characteristics. Prevention is the main strategy to reduce incidence and mortality rates of CRC. This can be achieved through strategies stimulating lifestyle changes, healthy diet habits, and early screening for high-risk individuals. To reduce the burden of CRC, public health officials should promote prevention and management of modifiable risk factors through national policies. The rising incidence and mortality rates of CRC in China may be timely curbed by clarifying specific epidemiological characteristics, optimizing early screening strategies, and strictly implementing diagnosis and treatment guidelines. Thus, this study aimed to collect and report the current research status on epidemiology and risk factors of CRC in China.

Epidemiology of inflammatory bowel disease in South America: A systematic review

BACKGROUND

The worldwide epidemiology of inflammatory bowel disease (IBD) is rapidly changing. Increasing Crohn’s disease (CD) and ulcerative colitis (UC) incidence and prevalence have been recorded in developing regions such as Asia, Africa and Eastern Europe where it was previously thought to be uncommon. Whether this is also the case in South America is not well known. Demonstration that developing regions worldwide have increasing IBD incidence would indicate that environmental change plays a significant role in the development of IBD.

AIM

To report the incidence, prevalence and disease characteristics of CD and UC within the South American continent.

METHODS

A systematic review was conducted by searching published studies in major international and regional databases (MEDLINE, EMBASE and Scopus) between January 1990 and December 2018. Outcomes considered were incidence, prevalence, phenotype, environmental and genetic factors, ethnicity and gender. A pair of independent reviewers screened and reviewed all identified articles.

RESULTS

One hundred and sixty two citations were initially retrieved with 18 studies included in this systematic review. The majority of included studies were from Brazil (n =13, 72%). The incidence of UC ranged from 4.3-5.3/100000 person-years whilst the incidence of CD ranged from 0.74-3.5/100000 person-years. Prevalence ranged from 15.0-24.1/100000 inhabitants for UC and from 2.4-14.1/100000 inhabitants for CD. The incidence and prevalence of both UC and CD has increased significantly in Brazil over the past 21 years. Pancolitis was the most common disease distribution in patients with UC whilst colonic involvement was the most common distribution in CD. People residing in urban areas were at higher risk of developing both CD and UC.

CONCLUSION

The IBD burden in South America is increasing at a rate possibly even greater than other developing regions around the world. There is a paucity of high-quality epidemiological studies and further robust and representative data are required to further explore modifiable risk factors and disease phenotypes.

IBD in the Elderly: Management Challenges and Therapeutic Considerations

PURPOSE OF REVIEW

Elderly patients with inflammatory bowel disease (IBD) are increasing in prevalence as our population ages and the incidence of IBD increases. The purpose of this review is to describe the management challenges in elderly IBD patients, including comorbid conditions and therapeutic considerations unique to the elderly population.

RECENT FINDINGS

The elderly experience coexisting comorbidities that complicate IBD management. The disease course and potential side effects of treatments can impact the elderly IBD patient differently than younger IBD patients. The duration for colorectal cancer surveillance (CRC) also remains controversial and should be individualized to determine when discontinuation is appropriate. Given greater safety considerations in the elderly IBD population, treatment targets and management goals require a more personalized approach in the elderly, taking into account coexisting comorbidities, inflammatory burden, and functional limitations.

Comparison of outcomes of continuation/discontinuation of 5-aminosalicylic acid after initiation of anti-tumor necrosis factor-alpha therapy in patients with inflammatory bowel disease

BACKGROUND

Few maintenance therapeutic options are available for inflammatory bowel disease (IBD). Data on the effects of continuing 5-aminosalicylic acid (5-ASA) treatment in patients who commence on biologics as maintenance treatment remain scarce. We evaluated IBD patient outcomes after continuation/discontinuation of 5-ASA when biologics were administered as maintenance treatment.

METHODS

We retrospectively reviewed the clinical, laboratory, and imaging data of patients diagnosed with IBD (ulcerative colitis (UC), 763; Crohn's disease (CD), 537) in the Gil Medical Center (GMC) from February 2005 to June 2018. We divided patients administered with biologics as maintenance treatment into those who did and did not continue on 5-ASA and compared the efficacies of the two treatment options using the log-rank test and Cox proportional hazards models.

RESULTS

Of 1300 total IBD patients, 128 (UC, 63; CD, 65) were prescribed biologics as induction and maintenance treatments. The median follow-up period was 109.5 weeks. All cases were divided into those who did or did not combine 5-ASA with biologics as maintenance treatments. Kaplan-Meier analysis showed that the event-free survival (exacerbation of disease activity) of UC patients treated with biologics and 5-ASA (n = 42) was not significantly lower than that of those taking biologics alone (n = 21) (log rank test, P = 0.68). The same was true of CD patients (n = 42, biologics and 5-ASA; n = 23, biologics only) (log rank test, P = 0.87).

CONCLUSIONS

Continuation of 5-ASA after initiation of anti-tumor necrosis factor-alpha agents did not improve prognosis in Korean IBD patients compared with that of those who discontinued 5-ASA during maintenance treatment, particularly in patients who experienced more than two disease aggravations.

Microbiota and mucosal defense in IBD: an update

Introduction: Inflammatory bowel diseases (IBD) are on the rise worldwide. This review covers the current concepts of the etiology of Crohn´s disease and ulcerative colitis by focusing on an unbalanced interaction between the intestinal microbiota and the mucosal barrier. Understanding these issues is of paramount importance for the development of targeted therapies aiming at the disease cause.Area covered: Gut microbiota alterations and a dysfunctional intestinal mucosa are associated with IBD. Here we focus on specific defense structures of the mucosal barrier, namely antimicrobial peptides and the mucus layer, which keep the gut microbiota at a distance under healthy conditions and are defective in IBD.Expert commentary: The microbiology of both forms of IBD is different but characterized by a reduced bacterial diversity and richness. Abundance of certain bacterial species is altered, and the compositional changes are related to disease activity. In IBD the mucus layer above the epithelium is contaminated by bacteria and the immune reaction is dominated by the antibacterial response. Human genetics suggest that many of the basic deficiencies in the mucosal response, due to Paneth cell, defensin and mucus defects, are primary. Nutrition may also be important but so far there is no therapy targeting the mucosal barrier.

Global smoking trends in inflammatory bowel disease: A systematic review of inception cohorts

Background and aims

The effect of smoking on the risk of developing inflammatory bowel diseases (IBD) may be heterogeneous across ethnicity and geography. Although trends in smoking for the general population are well described, it is unknown whether these can be extrapolated to the IBD cohort. Smoking prevalence trends specific to the global IBD cohort over time have not been previously reported. This is a systematic review of smoking prevalence specific to the IBD cohort across geography.

Methods

A systematic literature search was conducted on Medline and Embase from January 1^st 1946 to April 5^th 2018 to identify population-based studies assessing the prevalence of smoking at diagnosis in inception cohorts of Crohn’s disease(CD) or ulcerative colitis(UC). Studies that did not report smoking data from time of diagnosis or the year of IBD diagnosis were excluded. Prevalence of smoking in IBD was stratified by geography and across time.

Results

We identified 56 studies that were eligible for inclusion. Smoking prevalence data at diagnosis of CD and UC was collected from twenty and twenty-five countries respectively. Never-smokers in the newly diagnosed CD population in the West has increased over the last two decades, especially in the United Kingdom and Sweden; +26.6% and +11.2% respectively. Never-smokers at CD diagnosis in newly industrialised nations have decreased over the 1990s and 2000s; China (-19.36%). Never-smokers at UC diagnosis also decreased in China; -15.4%. The former-smoker population at UC diagnosis in China is expanding; 11%(1990–2006) to 34%(2011–2013).

Conclusion

There has been a reduction in the prevalence of smoking in the IBD cohort in the West. This is not consistent globally. Although, smoking prevalence has decreased in the general population of newly industrialised nations, this remains an important risk factor with longer term outcomes awaiting translation in both UC and CD.

Enteral Nutrition in Adult Crohn's Disease: Toward a Paradigm Shift

Medical and surgical treatments for Crohn's disease are associated with toxic effects. Medical therapy aims for mucosal healing and is achievable with biologics, immunosuppressive therapy, and specialised enteral nutrition, but not with corticosteroids. Sustained remission remains a therapeutic challenge. Enteral nutrition, containing macro- and micro-nutrients, is nutritionally complete, and is provided in powder or liquid form. Enteral nutrition is a low-risk and minimally invasive therapy. It is well-established and recommended as first line induction therapy in paediatric Crohn's disease with remission rates of up to 80%. Other than in Japan, enteral nutrition is not routinely used in the adult population among Western countries, mainly due to unpalatable formulations which lead to poor compliance. This study aims to offer a comprehensive review of available enteral nutrition formulations and the literature supporting the use and mechanisms of action of enteral nutrition in adult Crohn's disease patients, in order to support clinicians in real world decision-making when offering/accepting treatment. The mechanisms of actions of enteral feed, including their impact on the gut microbiome, were explored. Barriers to the use of enteral nutrition, such as compliance and the route of administration, were considered. All available enteral preparations have been comprehensively described as a practical guide for clinical use. Likewise, guidelines are reported and discussed.

Carbohydrate Monotony as Protection and Treatment for Inflammatory Bowel Disease

The nutritional developmental origins of inflammatory bowel disease[s] (IBDs: Crohn's disease or Crohn disease [CD] and ulcerative colitis [UC]) and their diet-based treatments continue to receive increasing attention. There is growing evidence for the success of nutrition-based treatments, such as exclusive enteral nutrition [EEN] and the specific carbohydrate diet [SCD], in both paediatric and adult patients. Beyond these two dietary interventions, symptomatic benefit in IBD has also been shown from a gluten-free diet [GFD] and paleolithic diet [PALEO], among others. These nutritional therapies may point to critical factors in not only the pathology, but also the pathogenesis of the disease group. It is difficult, however, to discern a common element within the large number of diet-based causation theories [e.g. emulsifiers, processed foods, refrigeration, increased total fat intake, low fibre intake, carbohydrate dominant food, etc.] and the varied dietary treatments of IBD. This Viewpoint article highlights that carbohydrate variation links diet-based causation theories, and that carbohydrate monotony or persistence is the commonly shared characteristic of diet-based IBD therapy. Further research directed towards carbohydrate monotony may critically advance the prevention and treatment of these highly morbid conditions.

Evolving Epidemiology of IBD

PURPOSE OF REVIEW

Once thought a disease of Western civilizations, the inflammatory bowel diseases (IBD) impose a global burden, now penetrating populations in Asia, Africa, and South America. We summarize similarities and differences in the epidemiology of IBD globally, highlighting gaps in knowledge where future study is needed.

RECENT FINDINGS

While incidence of IBD is stabilizing (or even decreasing) in many westernized regions, prevalence continues to grow due to a young age of onset and low mortality. In newly westernized regions, IBD is beginning to penetrate populations comparable to the rapid increases seen in North America, Europe, and Oceania in the last century. IBD imposes a significant fiscal and resource burden on healthcare systems. As global prevalence of these diseases continues to increase, we desperately need to anticipate the future burden to proactively prepare our healthcare systems for the challenges of increased patient load and aging populations with comorbid conditions and longer disease course.

Single probiotic supplement suppresses colitis-associated colorectal tumorigenesis by modulating inflammatory development and microbial homeostasis

BACKGROUND AND AIM

Chronic inflammation is a major contributor to the initiation and progression of cancers. Lactobacillus helveticus NS8, which was originally separated from fermented koumiss, exhibited anti-inflammatory functions in our prior studies. In this study, NS8 was investigated for its potential to prevent colitis-associated colorectal cancer (CAC).

METHODS

The protective effects of NS8 against CAC was explored by employing the azoxymethane plus dextran sodium sulfate-induced carcinogenesis mouse model. The prevalences of T cells expressing specific inflammatory cytokines were measured by flow cytometry at the early stage of CAC. Inflammatory modulation by NS8 was also tested in the Caco2-Raw264.7 cell co-culture system. The alternations in the intestinal microbiota following the health-inflammation-cancer sequence were analyzed by 16S rDNA sequencing.

RESULTS

Oral intake of NS8 lactobacilli clearly reduced tumor number and the degree of hyperplasia. The increased proliferation of enterocytes at the early stage of CAC was significantly suppressed by NS8, while the level of apoptosis was elevated. The anticancer effects of NS8 were associated with its anti-colitis outcomes before tumor formation. NS8 significantly suppressed the activation of NF-κB and upregulated the anti-inflammatory cytokine IL-10. Further analysis revealed the marked downregulation of IL-17-producing T cells by NS8. Furthermore, NS8 modulated intestinal dysbiosis by promoting beneficial commensal microbes while suppressing cancer-associated microbes. Notably, Bacteroides acidifaciens was the most sensitive commensal bacteria to NS8 intervention.

CONCLUSION

These results provide insight into the protective effects of L. helveticus NS8 against colorectal cancer.

Inflammatory bowel diseases: time of diagnosis, environmental factors, clinical course, and management - a follow-up study in a private inflammatory bowel disease center (2003-2017)

BACKGROUND

The governmental program of Brazilian Unified National Health System has already published studies on the incidence of inflammatory bowel diseases (IBD), but up until now, there have been no epidemiological studies in private centers in Brazil. However, these diseases tend to affect people from a higher socioeconomic class, mainly in the capital of MS state that has the third highest GDP in Brazil.

OBJECTIVES

The aim was to analyze an observational, descriptive study of an IBD database in a private center including: the side, behavior of the disease and medical management, the association of extra-intestinal manifestations, and the main clinical symptoms which led to the investigation and diagnosis of IBD.

PATIENTS AND METHODS

A cohort study was developed in which data of all patients with IBD were analyzed with SPSS software in a constructed electronic database.

RESULTS

Of 329 patients, 212 (64.4%) had Crohn's disease (CD) and 117 (35.6%) had ulcerative colitis (UC). Average age at diagnosis of CD was 36.19 (±14.33) and of UC was 41.61 (±15.37). An amount of 50.05% of the patients with CD and 72.7% (P<0.001) with UC were female. We have observed that concerning the first symptoms, diahrrea and blood feces corresponded to 70% in UC while in CD 50% of the patients presented diahrrea with blood feces, loss of weight corresponded to 50% and only diahrrea 25%. (P<0.001). Anti-TNFs corresponded to 56.2% being more frequent in CD 0.001%. CD patients used biologic therapy and antibiotics more frequently than those with UC. In conclusion, IBD is also frequent in private health care centers in Brazil; women are most affected. Symptoms such as diarrhea and bleeding, as well as diarrhea and weight loss, must be taken as warning signs to investigate for inflammatory disease. The use of biologic therapies is frequent in referral centers when patients have severe disease.

Past and Future Burden of Inflammatory Bowel Diseases Based on Modeling of Population-Based Data

BACKGROUND & AIMS

Inflammatory bowel diseases (IBDs) exist worldwide, with high prevalence in North America. IBD is complex and costly, and its increasing prevalence places a greater stress on health care systems. We aimed to determine the past current, and future prevalences of IBD in Canada.

METHODS

We performed a retrospective cohort study using population-based health administrative data from Alberta (2002-2015), British Columbia (1997-2014), Manitoba (1990-2013), Nova Scotia (1996-2009), Ontario (1999-2014), Quebec (2001-2008), and Saskatchewan (1998-2016). Autoregressive integrated moving average regression was applied, and prevalence, with 95% prediction intervals (PIs), was forecasted to 2030. Average annual percentage change, with 95% confidence intervals, was assessed with log binomial regression.

RESULTS

In 2018, the prevalence of IBD in Canada was estimated at 725 per 100,000 (95% PI 716-735) and annual average percent change was estimated at 2.86% (95% confidence interval 2.80%-2.92%). The prevalence in 2030 was forecasted to be 981 per 100,000 (95% PI 963-999): 159 per 100,000 (95% PI 133-185) in children, 1118 per 100,000 (95% PI 1069-1168) in adults, and 1370 per 100,000 (95% PI 1312-1429) in the elderly. In 2018, 267,983 Canadians (95% PI 264,579-271,387) were estimated to be living with IBD, which was forecasted to increase to 402,853 (95% PI 395,466-410,240) by 2030.

CONCLUSION

Forecasting prevalence will allow health policy makers to develop policy that is necessary to address the challenges faced by health systems in providing high-quality and cost-effective care.

The Multifactorial Etiopathogeneses Interplay of Inflammatory Bowel Disease: An Overview

The gastrointestinal system where inflammatory bowel disease occurs is central to the immune system where the innate and the adaptive/acquired immune systems are balanced in interactions with gut microbes under homeostasis conditions. This article overviews the high-throughput research screening on multifactorial interplay between genetic risk factors, the intestinal microbiota, urbanization, modernization, Westernization, the environmental influences and immune responses in the etiopathogenesis of inflammatory bowel disease in humans. Inflammatory bowel disease is an expensive multifactorial debilitating disease that affects thousands new people annually worldwide with no known etiology or cure. The conservative therapeutics focus on the established pathology where the immune dysfunction and gut injury have already happened but do not preclude or delay the progression. Inflammatory bowel disease is evolving globally and has become a global emergence disease. It is largely known to be a disease in industrial-urbanized societies attributed to modernization and Westernized lifestyle associated with environmental factors to genetically susceptible individuals with determined failure to process certain commensal antigens. In the developing nations, increasing incidence and prevalence of inflammatory bowel disease (IBD) has been associated with rapid urbanization, modernization and Westernization of the population. In summary, there are identified multiple associations to host exposures potentiating the landscape risk hazards of inflammatory bowel disease trigger, that include: Western life-style and diet, host genetics, altered innate and/or acquired/adaptive host immune responses, early-life microbiota exposure, change in microbiome symbiotic relationship (dysbiosis/dysbacteriosis), pollution, changing hygiene status, socioeconomic status and several other environmental factors have long-standing effects/influence tolerance. The ongoing multipronged robotic studies on gut microbiota composition disparate patterns between the rural vs. urban locations may help elucidate and better understand the contribution of microbiome disciplines/ecology and evolutionary biology in potentially protecting against the development of inflammatory bowel disease.

No Association Between Consumption of Sweetened Beverages and Risk of Later-Onset Crohn's Disease or Ulcerative Colitis

BACKGROUND & AIMS

Consumption of sweetened beverages has been associated with inflammation based on measurements of C-reactive protein and tumor necrosis factor, as well as immune-mediated disorders including rheumatoid arthritis. We investigated associations with Crohn's disease (CD) or ulcerative colitis (UC).

METHODS

We conducted a prospective cohort study of 83,042 participants (age, 44-83 y) enrolled in the Cohort of Swedish Men or the Swedish Mammography Study. Dietary and lifestyle data were collected using a validated food frequency questionnaire at baseline in 1997. Diagnoses of CD and UC were ascertained from the Swedish Patient Register. We used Cox proportional hazards modeling to calculate hazard ratios and 95% CIs.

RESULTS

Through December of 2014, we confirmed 143 incident cases of CD (incidence rate, 11 cases/100,000 person-years) and 349 incident cases of UC (incidence rate, 28 cases/100,000 person-years) over 1,264,345 person-years of follow-up evaluation. Consumption of sweetened beverages was not associated with increased risk of CD (Ptrend = .34) or UC (Ptrend = .40). Compared with participants who reported no consumption of sweetened beverages, the multivariable-adjusted hazard ratios for 1 or more servings per day were 1.02 for CD (95% CI, 0.60-1.73) and 1.14 for UC (95% CI, 0.83-1.57). The association between consumption of sugar-sweetened beverages and risk of CD or UC were not modified by age, sex (cohort), body mass index, or smoking (all Pinteraction ≥ .12).

CONCLUSIONS

In analyses of data from 2 large prospective cohort studies from Sweden, we observed no evidence for associations between consumption of sweetened beverages and later risk of CD or UC.

Population Density and Risk of Inflammatory Bowel Disease: A Prospective Population-Based Study in 13 Countries or Regions in Asia-Pacific

INTRODUCTION

Living in an urban environment may increase the risk of developing inflammatory bowel disease (IBD). It is unclear if this observation is seen globally. We conducted a population-based study to assess the relationship between urbanization and incidence of IBD in the Asia-Pacific region.

METHODS

Newly diagnosed IBD cases between 2011 and 2013 from 13 countries or regions in Asia-Pacific were included. Incidence was calculated with 95% confidence interval (CI) and pooled using random-effects model. Meta-regression analysis was used to assess incidence rates and their association with population density, latitude, and longitude.

RESULTS

We identified 1175 ulcerative colitis (UC), 656 Crohn's disease (CD), and 37 IBD undetermined (IBD-U). Mean annual IBD incidence per 100 000 was 1.50 (95% CI: 1.43-1.57). India (9.31; 95% CI: 8.38-10.31) and China (3.64; 95% CI, 2.97-4.42) had the highest IBD incidence in Asia. Incidence of overall IBD (incidence rate ratio [IRR]: 2.19; 95% CI: 1.01-4.76]) and CD (IRR: 3.28; 95% CI: 1.83-9.12) was higher across 19 areas of Asia with a higher population density. In China, incidence of IBD (IRR: 2.37; 95% CI: 1.10-5.16) and UC (IRR: 2.63; 95% CI: 1.2-5.8) was positively associated with gross domestic product. A south-to-north disease gradient (IRR: 0.94; 95% CI: 0.91-0.98) was observed for IBD incidence and a west-to-east gradient (IRR: 1.14; 95% CI: 1.05-1.24) was observed for CD incidence in China. This study received IRB approval.

CONCLUSIONS

Regions in Asia with a high population density had a higher CD and UC incidence. Coastal areas within China had higher IBD incidence. With increasing urbanization and a shift from rural areas to cities, disease incidence may continue to climb in Asia.

Enterotype Variations of the Healthy Human Gut Microbiome in Different Geographical Regions

Enterotypes are used for classifying individuals based on the gut microbiome. A number of studies are available to find the Enterotypes in healthy individuals; however, most of them lack comparisons at the world level. We analyzed the healthy human gut microbiomes of 495 datasets available in the European Nucleotide Archive (ENA) database derived from fifteen countries from four continents. Firmicutes and Bacteroidetes were the two most abundant phyla in the healthy human gut, worldwide. A high ratio of Proteobacteriato Actinobacteria and a low abundance of Prevotella were identified as the indicators of IBD. Prevotella, Bacteroides, and Bifidobacterium were identified as the Enterotypes in the inter-continental comparisons. At the intra-continental level, two (Bacteroides and Ruminococcaceae), four (Faecalibacterium, Bacteroides, Prevotella, and Clostridiales), and two (Prevotella, Bacteroides/Bifidobacterium) Enterotypes were identified in the American, European, and Asian continents, respectively. In addition, a high abundance of the unknown genus of Ruminococcaeae was observed in the Colombian human gut microbiome. A substantial impact of the geographical distance was observed on human gut microbiome variations, demonstrating a cumulative effect of factors, including dietary habits, genetics, lifestyle, environment, and climate, etc.

Increased Risk of Ulcerative Colitis in Patients with Periodontal Disease: A Nationwide Population-Based Cohort Study

Both periodontal disease (PD) and inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are important diseases of the alimentary tract. Microbiome and immune-mediated inflammatory processes play important roles in these diseases. An association between PD and IBD may exist. This study investigated the risk of IBD in patients with PD. This study used data from the National Health Insurance Research Database of Taiwan from 1996 to 2013. A total of 27,041 patients with PD were enrolled as a study group, and 108,149 patients without PD were selected as the control group after matching by gender, age, insured region, urbanization, and income with a 1:4 ratio. Cox proportional hazards regression was used to calculate the risk of IBD. Of the 135,190 participants enrolled in this study, 5392 (4%) with newly diagnosed IBD were identified. The overall incidence of subsequent IBD was similar in both groups (3.8% vs. 4%, adjusted hazard ratio (aHR) = 1.01, 95% confidence interval (CI): 0.94⁻1.08). However, an increased risk of UC in the PD group was found after adjusting confounding factors (aHR: 1.56, 95% CI: 1.13⁻2.15; p < 0.05). This study demonstrated that patients with PD had approximately one-half higher risk of subsequent UC. Further studies are warranted to elucidate the relationship between PD and UC.

The Impact of Inflammatory Bowel Disease in Canada 2018: Epidemiology

Canada has among the highest incidence and prevalence of inflammatory bowel disease (IBD) in the world. After decades of rising incidence of IBD in Canada during the 20th Century, the prevalence of IBD in 2018 is 0.7% of the Canadian population. Forecasting models predict that prevalence of IBD will continue to rise to 1.0% of the population by 2030. In 2018, the number of Canadians living with IBD is approximately 270,000 and is predicted to rise to 403,000 Canadians in 2030. Inflammatory bowel disease affects all age groups with adolescents and young adults at highest risk of diagnosis. Canadians of all ethnicities are being diagnosed with IBD including known high-risk groups such as Ashkenazi Jews and offspring of South Asian immigrants who were previously thought to be low risk. Moreover, IBD has evolved into a global disease with rising incidence in newly industrialized countries in Asia and South America. The causes of IBD remain unsolved; however, the high rates of disease in Western countries and its emergence in newly industrialized countries suggest that environmental factors associated with urbanization, modernization, or Western diets may be pertinent to understanding the pathogenesis of the disease.

Highlights

1. Canada continues to have among the highest prevalence of IBD in the world.

2. Today, approximately 270,000 Canadians live with IBD. By 2030 it is estimated that nearly 403,000 Canadians will have a diagnosis of IBD.

3. Inflammatory bowel disease has become a worldwide disease with increasing rates in Asia, Africa, and South America—continents where IBD was rarely diagnosed prior to 1990.

4. The causes of IBD are unknown, but the high rates of disease over the past 60 years in Western countries and the emergence of disease in developing countries suggest that factors associated with urbanization, modernization, or Western diets may be pertinent to understanding the pathogenesis of the disease.

5. Many of the leading hypotheses as to the causes of IBD tie in with alteration of the gut microbiome, the suite of organisms that reside in the bowel and maintain bowel health throughout life.

Key Summary Points

1. The incidence (the number of new diagnoses annually) of IBD rose throughout the 20th century in Canada and then stabilized at the turn of the 21st century.

2. The prevalence (the total number of diagnosed persons in the population) of IBD in Canada is among the highest in the world.

3. Today, 270,000 (0.7%, or 7 in 1000) Canadians are estimated to live with IBD. By 2030, that number is expected to rise to 403,000 Canadians (1% or 1 in 100).

4. Inflammatory bowel disease can be diagnosed at any age. However, the age groups that are most likely to be diagnosed are adolescents and young adults from 20 to 30 years of age.

5. Inflammatory bowel disease in Canada affects the lives of Canadians of all ethnicities, including known high-risk groups such as Ashkenazi Jews, and those thought previously to be at low risk, such as first-generation offspring of South Asian immigrants.

6. Canadian health policy makers will need to prepare the Canadian health care system for the rising burden of IBD.

7. As newly industrialized countries in Asia, Africa, and South America are transitioning to a Westernized society, IBD has emerged and its incidence in these countries is rising rapidly.

8. The gut microbiome includes microorganisms that maintain digestive health. Thus, changes in the microbiome, which may change the immune system’s response to triggers, may be important in initiating and perpetuating IBD.

9. A number of factors can alter the gut microbiome and early childhood may be a particularly important time such that breastfeeding, early life diet, use of antibiotics, infections, and other environmental exposures may impact the gut microbiome in such a way that facilitates developing IBD.

10. Smoking is associated with an increased risk and worsening disease course of Crohn’s disease. Quitting smoking is associated with an increased risk of developing ulcerative colitis. Therefore, never initiating smoking can mitigate the risk for IBD. Educational programs aimed at those at-risk for IBD should emphasize the risk of starting to smoke tobacco.

11. Modifying exposure to environmental risk factors associated with the Westernization of society (e.g., Western diet and lifestyles) may provide an avenue for reducing the risk of IBD in Canada and worldwide.

Gaps in Knowledge and Future Directions

1. While the incidence of IBD appears to be stabilizing in some regions in Canada, IBD may be occurring more frequently in certain populations such as in children, South Asians, Ashkenazi Jews, and immigrants. Future research should focus on the changing demographics of IBD in Canada.

2. The prevalence of IBD will rise steadily over the next decade. To enable better health care system planning and to respond adequately to the increasing burden of IBD, ongoing surveillance of the epidemiology and health services utilization of IBD in Canada is necessary.

3. Most studies have focused on the mortality associated with IBD. Future research is necessary to assess health-adjusted life expectancy and overall life expectancy for those living with IBD.

4. Analyses of resources, infrastructure, and personnel need to be modeled into the future in order to prepare our health care system for the rising burden of IBD.

5. Research on the interaction between genes, microbes, and our environment will inform our understanding of the pathogenesis of IBD, information necessary to prevent IBD in the future.

Cost-Effectiveness of Different Strategies for the Treatment of Moderate-to-Severe Ulcerative Colitis

BACKGROUND

Knowledge regarding the economic outcomes of anti-tumour necrosis factor-α (anti-TNFα) and oral Janus kinase inhibitor (JAKi) therapies for the treatment of ulcerative colitis (UC) is limited. We conducted this analysis to assess the economic outcomes of anti-TNFα, antiadhesion molecule inhibitors (anti-AMi), and oral JAKi therapies for the treatment of UC from the perspectives of the United Kingdom (UK) and China, which are the representatives of high-income and middle-income regions, respectively.

METHODS

A Markov model-based economic analysis was performed by incorporating effectiveness and utility data obtained from the literature and costs based on publicly available reports. The UK and Chinese health care perspectives were adopted to evaluate different intervention treatment sequences, including 14 treatment sequences consisting of conventional therapy, tofacitinib, adalimumab, vedolizumab, golimumab, and infliximab. The participants were the patients with moderate-to-severe UC eligible for anti-TNFα, anti-Ami, and JAKi treatment. Cost, quality-adjusted life years (QALYs), and the incremental cost-effectiveness ratio (ICER) were reported.

RESULTS

Compared to other alternatives comprising adalimumab, golimumab, and infliximab, the use of a treatment sequence comprising tofacitinib and vedolizumab always had better health outcomes. The most cost-effective options in the UK included the sequences comprising tofacitinib and vedolizumab, and the most cost-effective treatment option in China was tofacitinib. There were uncertainties surrounding the results, the key drivers of which being the utility values, effectiveness of conventional therapy, and relative efficacy of the active treatments.

CONCLUSIONS

The treatment with tofacitinib and vedolizumab for moderate-to-severe UC is likely to be the most favorable cost-effective option in the high-income UK, and tofacitinib is the most cost-effective option in the middle-income China.

Helicobacter pylori infection and inflammatory bowel disease: a crosstalk between upper and lower digestive tract

Helicobacter pylori has coexisted with humans for approximately 60,000 years and greater than 50% of the global population is infected with H. pylori. H. pylori was successfully cultured in vitro in 1983 and studies of H. pylori have achieved substantial advances over the last 35 years. Since then, H. pylori has been characterized as the primary pathogenic factor for chronic gastritis, peptic ulcer, and gastric malignancy. Numerous patients have received H. pylori eradication treatment, but only 1-2% of H. pylori-infected individuals ultimately develop gastric cancer. Recently, numerous epidemiological and basic experimental studies suggested a role for chronic H. pylori infection in protecting against inflammatory bowel disease (IBD) by inducing systematic immune tolerance and suppressing inflammatory responses. Here we summarize the current research progress on the association between H. pylori and IBD, and further describe the detailed molecular mechanism underlying H. pylori-induced dendritic cells (DCs) with the tolerogenic phenotype and immunosuppressive regulatory T cells (Tregs). Based on the potential protective role of H. pylori infection on IBD, we suggest that the interaction between H. pylori and the host is complicated, and H. pylori eradication treatment should be administered with caution, especially for children and young adults.

Development of a Traditional Chinese Medicine Syndrome-Specific Scale for Ulcerative Colitis: The Large Intestine Dampness-Heat Syndrome Questionnaire

The aim of this study was to develop and validate the large intestine dampness-heat syndrome questionnaire (LIDHSQ) for patients with ulcerative colitis (UC). The domains and items of the LIDHSQ were developed according to standard procedures, namely, construct definition, item generation, language testing, content validity, pilot study, and validation study. At first, a total of 20 items in 3 domains were generated based on literature review and expert consultation. After the item selection, the LIDHSQ contains 11 items in three domains: disease-related domain (diarrhoea, abdominal pain, bloody purulent stool, and mucus stool), heat domain (fever, dry mouth, red tongue, yellow fur, and anal burning), and dampness domain (greasy fur and defecation disorder). The Cronbach's alphas of all domains were greater than 0.6. All of the intraclass correlation coefficients were greater than 0.8. The LIDHSQ and domain scores of the patients with LIDHS were higher than those of the patients with other syndromes (P < 0.001). The area under the receiver operating characteristic curve of the LIDHSQ was 0.900, with a 95% confidence interval of 0.872–0.928. When the cut-off value of the LIDHSQ was ≥ 7, the sensitivity and specificity were 0.867 and 0.854, respectively. The LIDHSQ is valid and reliable for measuring LIDHS in UC patients with good diagnostic efficacy. We recommend the use of the LIDHSQ in Chinese UC patients.

Urbanization and the gut microbiota in health and inflammatory bowel disease

In the 21st century, urbanization represents a major demographic shift in developed and developing countries. Rapid urbanization in the developing world has been associated with an increasing incidence of several autoimmune diseases, including IBD. Patients with IBD exhibit a decrease in the diversity and richness of the gut microbiota, while urbanization attenuates the gut microbial diversity and might have a role in the pathogenesis of IBD. Environmental exposures during urbanization, including Westernization of diet, increased antibiotic use, pollution, improved hygiene status and early-life microbial exposure, have been shown to affect the gut microbiota. The disparate patterns of the gut microbiota composition in rural and urban areas offer an opportunity to understand the contribution of a 'rural microbiome' in potentially protecting against the development of IBD. This Perspective discusses the effect of urbanization and its surrogates on the gut microbiome (bacteriome, virome, mycobiome and helminths) in both human health and IBD and how such changes might be associated with the development of IBD.

Young mice expel the tapeworm Hymenolepis diminuta and are protected from colitis by triggering a memory response with worm antigen

Infection with helminth parasites reduces the severity of concomitant inflammatory disease in adult mice. There is an alarming increase of inflammatory bowel disease (IBD) in children. It is important to determine whether helminth therapy would be of value in pediatric IBD and whether triggering immunological memory to the worm would be anticolitic. Three-week-old (young) and eight-week-old (adult) Balb/c mice were infected with H. diminuta, and infectivity and T helper 2 (Th2) immunity were assessed. Other mice received H. diminuta with or without a crude worm extract ( HdE) 28-42 days postinfection (dpi) with or without dinitrobenzene sulphonic acid [DNBS, 1.5 mg (young) or 3 mg (adults), ir], and colitis was assessed 72 h later. Infected young mice developed Th2 immunity and expelled H. diminuta; expulsion was delayed by ~2 days compared with adult mice. Colitis, as gauged by macroscopic disease and histopathology scores, was less severe in young mice infected 10 days, but not 8 days, before DNBS. Protection against DNBS-induced colitis was accompanied by an increased capacity to make interleukin (IL)-4 and IL-10. Mice infected with H. diminuta were not protected from DNBS-colitis when challenged 28 days later; however, injection of these mice with HdE coincident with DNBS resulted in less disease and increased splenic IL-4 and IL-10. Using a boost (500 μg HdE, 28 dpi) and repeat HdE (100 μg, 42 dpi) regimen with infected mice suppressed DNBS-colitis, as did adoptive transfer of splenic CD4⁺ T cells from infected mice with low-dose HdE challenge. Should these data translate to IBD, then helminth therapy could be of value in pediatric-onset IBD, and defining the antigen(s) that elicit antihelminth immunological memory could serve as an anticolitic approach in previously infected individuals. NEW & NOTEWORTHY This study demonstrates that juvenile mice are protected from colitis by infection with the tapeworm Hymenolepis diminuta and that using worm antigen to trigger an immunological memory response in previously infected mice can be used to limit the severity of colitis.

Adherent-invasive Escherichia coli in inflammatory bowel disease

Intestinal microbiome dysbiosis has been consistently described in patients with IBD. In the last decades, Escherichia coli, and the adherent-invasive E coli (AIEC) pathotype in particular, has been implicated in the pathogenesis of IBD. Since the discovery of AIEC, two decades ago, progress has been made in unravelling these bacteria characteristics and its interaction with the gut immune system. The mechanisms of adhesion of AIEC to intestinal epithelial cells (via FimH and cell adhesion molecule 6) and its ability to escape autophagy when inside macrophages are reviewed here. We also explore the existing data on the prevalence of AIEC in patients with Crohn's disease and UC, and the association between the presence of AIEC and disease location, activity and postoperative recurrence. Finally, we highlight potential therapeutic strategies targeting AIEC colonisation of gut mucosa, including the use of phage therapy, bacteriocins and antiadhesive molecules. These strategies may open new avenues for the prevention and treatment of IBD in the future.

Environmental triggers in IBD: a review of progress and evidence

A number of environmental factors have been associated with the development of IBD. Alteration of the gut microbiota, or dysbiosis, is closely linked to initiation or progression of IBD, but whether dysbiosis is a primary or secondary event is unclear. Nevertheless, early-life events such as birth, breastfeeding and exposure to antibiotics, as well as later childhood events, are considered potential risk factors for IBD. Air pollution, a consequence of the progressive contamination of the environment by countless compounds, is another factor associated with IBD, as particulate matter or other components can alter the host's mucosal defences and trigger immune responses. Hypoxia associated with high altitude is also a factor under investigation as a potential new trigger of IBD flares. A key issue is how to translate environmental factors into mechanisms of IBD, and systems biology is increasingly recognized as a strategic tool to unravel the molecular alterations leading to IBD. Environmental factors add a substantial level of complexity to the understanding of IBD pathogenesis but also promote the fundamental notion that complex diseases such as IBD require complex therapies that go well beyond the current single-agent treatment approach. This Review describes the current conceptualization, evidence, progress and direction surrounding the association of environmental factors with IBD.

Worldwide incidence and prevalence of inflammatory bowel disease in the 21st century: a systematic review of population-based studies

BACKGROUND

Inflammatory bowel disease is a global disease in the 21st century. We aimed to assess the changing incidence and prevalence of inflammatory bowel disease around the world.

METHODS

We searched MEDLINE and Embase up to and including Dec 31, 2016, to identify observational, population-based studies reporting the incidence or prevalence of Crohn's disease or ulcerative colitis from 1990 or later. A study was regarded as population-based if it involved all residents within a specific area and the patients were representative of that area. To be included in the systematic review, ulcerative colitis and Crohn's disease needed to be reported separately. Studies that did not report original data and studies that reported only the incidence or prevalence of paediatric-onset inflammatory bowel disease (diagnosis at age <16 years) were excluded. We created choropleth maps for the incidence (119 studies) and prevalence (69 studies) of Crohn's disease and ulcerative colitis. We used temporal trend analyses to report changes as an annual percentage change (APC) with 95% CI.

FINDINGS

We identified 147 studies that were eligible for final inclusion in the systematic review, including 119 studies of incidence and 69 studies of prevalence. The highest reported prevalence values were in Europe (ulcerative colitis 505 per 100 000 in Norway; Crohn's disease 322 per 100 000 in Germany) and North America (ulcerative colitis 286 per 100 000 in the USA; Crohn's disease 319 per 100 000 in Canada). The prevalence of inflammatory bowel disease exceeded 0·3% in North America, Oceania, and many countries in Europe. Overall, 16 (72·7%) of 22 studies on Crohn's disease and 15 (83·3%) of 18 studies on ulcerative colitis reported stable or decreasing incidence of inflammatory bowel disease in North America and Europe. Since 1990, incidence has been rising in newly industrialised countries in Africa, Asia, and South America, including Brazil (APC for Crohn's disease +11·1% [95% CI 4·8-17·8] and APC for ulcerative colitis +14·9% [10·4-19·6]) and Taiwan (APC for Crohn's disease +4·0% [1·0-7·1] and APC for ulcerative colitis +4·8% [1·8-8·0]).

INTERPRETATION

At the turn of the 21st century, inflammatory bowel disease has become a global disease with accelerating incidence in newly industrialised countries whose societies have become more westernised. Although incidence is stabilising in western countries, burden remains high as prevalence surpasses 0·3%. These data highlight the need for research into prevention of inflammatory bowel disease and innovations in health-care systems to manage this complex and costly disease.

FUNDING

None.

Development of an XBP1 agonist, HLJ2, as a potential therapeutic agent for ulcerative colitis

There is a severe lack of effective treatments for ulcerative colitis (UC), a recurrent and intractable inflammatory bowel disease. The identification of valid targets and new drugs is an urgent need. In this study, we identified the XBP-1 agonist HLJ2 as a promising treatment candidate. In an in vivo mouse model of DSS-induced colitis, HLJ2 decreased weight loss, colon contracture, disease activity index (DAI), colon mucosa damage index (CMDI) and histopathological index (HI). HLJ2 also decreased myeloperoxidase (MPO) activity and reduced production of the inflammatory cytokines TNF-α, IL-1β, and IL-6. HLJ2 improved intestinal mucosa damage induced by dextran sodium sulfate (DSS) and increased the expression of ZO-1 and claudin-1. Fecal 16s rRNA high-throughput sequencing demonstrated a significant improvement in UC intestinal dysbacteriosis in mice treated with HLJ2, including increased abundance of probiotics such as Lachnospiraceae, Prevotellaceae, and Lactobacillaceae. At the same time there was a reduction in the abundance of pathogenic or conditional pathogenic microorganisms such as Bacteroidaceae, Porphyromonadaceae, Deferribacteraceae, and Pseudomonadaceae in HLJ2-treated mice compared with untreated mice. Our results demonstrated that the XBP1 agonist HLJ2 inhibits inflammation, regulates the intestinal flora, and protects the intestinal mucosa. It is thus a potential therapeutic agent for ulcerative colitis.

The intricate connection between diet, microbiota, and cancer: A jigsaw puzzle

The microbial community has a decisive role in determining our health and disease susceptibility. Presumably, this is closely associated with the complex community network of bacteria, fungi, archaea and viruses that reside our guts. This dynamic ecosystem exists in a symbiotic relationship with its host and plays a fundamental role in the hosts' physiological functions. The microbial community is highly personalized and therefore exhibits a high degree of inter-individual variability, which is dependent on host specifics such as genetic background, physiology and lifestyle. Although the gut microbiota is shaped early on during birth, there are several factors that affect the composition of microbiota during childhood and adulthood. Among them diet appears to be a consistent and prominent one. The metabolic activity of bacteria affects food digestion, absorption, energy production, and immunity. Thus, definition of the microbiota composition and functional profiles in response to a particular diet may lead to critical information on the direct and indirect role/use of the bacterial community during health and disease. In this review, I discuss gut microbiota and its potential link to cancer with specific emphasis on metabolism and diet.