The association between Helicobacter pylori infection and inflammatory bowel disease based on meta-analysis

Comparative maintenance performance of all biologic agents and small molecules in ulcerative colitis: a network meta-analysis

BACKGROUND AND AIMS

Βiologic agents and small molecules have expanded the therapeutic armamentarium of moderate to severe ulcerative colitis (UC). However, their comparative efficacy and safety performance as maintenance treatments have not been sufficiently explored. We performed a systematic review and network meta-analysis (NWM) to assess the comparative efficacy and safety of all approved and emerging treatments for maintenance in moderate to severe UC.

METHODS

We searched Pubmed/Medline, EMBASE, and Cochrane Library databases for relevant RCTs through April 2023. The primary endpoint was clinical remission at the end of the maintenance therapy. Data were analyzed by means of a Bayesian NWM. The ranking probability concerning efficacy and safety was evaluated by means of surfaces under cumulative ranking (SUCRA) values.

RESULTS

There were 20 eligible RCTs with 7660 patients randomized to 20 treatments. RCTs were grouped into two study designs, that is, re-randomization of patients after an induction period and treat-through patients. Concerning efficacy, in re-randomized patients, upadacitinib 30 mg/day was ranked first (SUCRA 94.9%) whereas in treat-through patients etrasimod 2 mg/day was ranked first (SUCRA 91.1%). The integrated efficacy-safety hierarchical analysis, showed that tofacitinib 10 mg had the best efficacy-safety therapeutic profile in re-randomized patients, whereas in treat-through patients infliximab 3.5 mg/Kg Q8W showed the best efficacy-safety profile.

CONCLUSION

For maintenance treatment, in moderate to severe UC, this NWM showed that upadacitinib 30 mg/day and etrasimod 2 mg/day were ranked best for efficacy in re-randomized and treat-through patients respectively. Tofacitinib 10 mg/day and infliximab 3.5 mg/Kg Q8W showed the best efficacy-safety therapeutic profile in re-randomized and treat-through patients respectively.

Dual RNA sequencing of Helicobacter pylori and host cell transcriptomes reveals ontologically distinct host-pathogen interaction

Helicobacter pylori is a highly successful pathogen that poses a substantial threat to human health. However, the dynamic interaction between H. pylori and the human gastric epithelium has not been fully investigated. In this study, using dual RNA sequencing technology, we characterized a cytotoxin-associated gene A (cagA)-modulated bacterial adaption strategy by enhancing the expression of ATP-binding cassette transporter-related genes, metQ and HP_0888, upon coculturing with human gastric epithelial cells. We observed a general repression of electron transport-associated genes by cagA, leading to the activation of oxidative phosphorylation. Temporal profiling of host mRNA signatures revealed the downregulation of multiple splicing regulators due to bacterial infection, resulting in aberrant pre-mRNA splicing of functional genes involved in the cell cycle process in response to H. pylori infection. Moreover, we demonstrated a protective effect of gastric H. pylori colonization against chronic dextran sulfate sodium (DSS)-induced colitis. Mechanistically, we identified a cluster of propionic and butyric acid-producing bacteria, Muribaculaceae, selectively enriched in the colons of H. pylori-pre-colonized mice, which may contribute to the restoration of intestinal barrier function damaged by DSS treatment. Collectively, this study presents the first dual-transcriptome analysis of H. pylori during its dynamic interaction with gastric epithelial cells and provides new insights into strategies through which H. pylori promotes infection and pathogenesis in the human gastric epithelium.

IMPORTANCE

Simultaneous profiling of the dynamic interaction between Helicobacter pylori and the human gastric epithelium represents a novel strategy for identifying regulatory responses that drive pathogenesis. This study presents the first dual-transcriptome analysis of H. pylori when cocultured with gastric epithelial cells, revealing a bacterial adaptation strategy and a general repression of electron transportation-associated genes, both of which were modulated by cytotoxin-associated gene A (cagA). Temporal profiling of host mRNA signatures dissected the aberrant pre-mRNA splicing of functional genes involved in the cell cycle process in response to H. pylori infection. We demonstrated a protective effect of gastric H. pylori colonization against chronic DSS-induced colitis through both in vitro and in vivo experiments. These findings significantly enhance our understanding of how H. pylori promotes infection and pathogenesis in the human gastric epithelium and provide evidence to identify targets for antimicrobial therapies.

Embedding of exogenous B cell epitopes on the surface of UreB structure generates a broadly reactive antibody response against Helicobacter pylori

Since Helicobacter pylori (H. pylori) resistance to antibiotic regimens has increased, vaccination is becoming an increasingly important alternative therapy to control H. pylori infection. UreB, FlaA, AlpB, SabA, and HpaA proteins of H. pylori were previously proved to be used as candidate vaccine antigens. Here, we developed an engineered antigen based on a recombinant chimeric protein containing a structural scaffold from UreB and B cell epitopes from FlaA, AlpB, SabA, and HpaA. The multi-epitope chimeric antigen, named MECU, could generate a broadly reactive antibody response including antigen-specific antibodies and neutralising antibodies against H. pylori urease and adhesins. Moreover, therapeutic immunisation with MECU could reduce H. pylori colonisation in the stomach and protect the stomach in BALB/c mice. This study not only provides promising immunotherapy to control H. pylori infection but also offers a reference for antigen engineering against other pathogens.

Helicobacter pylori in children: think before you kill the bug!

Since the discovery of Helicobacter pylori (H. pylori) as the causative organism for gastric and duodenal ulcers four decades ago and subsequent recognition as class 1 gastric carcinogen, countless numbers of studies have been conducted and papers published, on the efficacy of various management strategies to eradicate the infection. In adults, a global consensus by the experts in the field concluded that H. pylori gastritis is an infectious disease and requires treatment irrespective of the presence or absence of symptoms due to the potential for serious complication like peptic ulcer disease and gastric neoplasia. However, although more than half the world's population harbors H. pylori, these serious complications occur only in a small minority of the infected population, even less so in childhood. More importantly, there is accumulating evidence for beneficial role of H. pylori against many chronic health conditions, from several epidemiological and laboratory studies. No doubt, eradication therapy is indicated in children with H. pylori-related peptic ulcer disease. Even though the pediatric guidelines from various learned societies recommend against a "test and treat" strategy, this is not always adhered to. With the accumulating evidence of the possible beneficial role of H. pylori, it is time to pause and think, are we causing more harm than good by eradicating H. pylori in every child who has this bug?

A systematic review, pairwise meta-analysis and network meta-analysis of randomized controlled trials exploring the role of fecal microbiota transplantation in irritable bowel syndrome

BACKGROUND

Treatment is a challenge in Irritable Bowel Syndrome (IBS) and fecal microbiota transplantation (FMT) has attracted significant interest. Network meta-analysis (NWM) has been established as an evidence-synthesis tool that incorporates direct and indirect evidence in a collection of randomized controlled trials (RCTs) comparing therapeutic intervention competing for similar therapeutic results. No NWM exists concerning the comparative effectiveness and safety of various FMT modalities for IBS.

AIM

We updated pairwise meta-analyses published in the past and assessed the comparative effectiveness and safety of various FMT delivery modalities for IBS.

METHODS

Pairwise meta-analyses and Bayesian NWM were performed. Heterogeneity, consistency of results and publication bias were explored.

RESULTS

Of 510 titles raised by initial search, seven RCTs were entered into meta-analyses and NWM. They included 470 patients and controls, in whom four FMT delivery modalities were used, that is via colonoscopy, nasojejunal tube, duodenoscope and capsules per os. In the pairwise meta-analysis, the pooled results showed that overall FMT was not superior to placebo, whereas the subgroup analyses showed that FMT via duodenoscope and nasojejunal tube was superior. The NWM showed that 60-g FMT via duodenoscope had the highest efficacy (OR, 26.38; 95% CI, 9.22-75.51) and was by far the highest in the efficacy ranking (SUCRA, 98.8%).

CONCLUSION

The pooled results showed no overall advantage of FMT over placebo in IBS. However, upper GI delivery (via duodenoscopy or nasojejunal tube) proved to be effective. Consequently, well-designed RCTs are needed to ensure the efficacy and safety profile before FMT can be applied in everyday clinical practice for IBS patients.

Current role of tailored therapy in treating Helicobacter pylori infections. A systematic review, meta-analysis and critical analysis

BACKGROUND AND AIMS

Recent guidelines dictate that all Helicobacter pylori (H. pylori) infected subjects should receive curative therapy. The efficacy of empirical regimens for H. pylori eradication might decline with bacterial, drug, and host factors. The necessity of a tailored therapy still remains controversial. Here we provide a meta-analysis of the current status of susceptibility-based (tailored) therapy in which susceptibility-based therapies were compared to the currently accepted choice of empiric therapy. In this rapidly closing era, neither the susceptibility nor empiric therapies were routinely optimized, such that we report the outcome of comparisons on the efficacy of unoptimized tailored vs. locally preferred empiric treatments.

METHODS

PubMed, Medline, and Embase databases were searched using suitable keywords. Individual and pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using the fixed- or random-effects model as appropriate. Heterogeneity was calculated employing the Cochrane Q test and I² values, whereas the possibility of publication bias was examined by constructing funnel plots. Additionally, subgroup and sensitivity analyses were performed.

RESULTS

Thirty-four studies were included with a total of 9613 patients. Tailored therapy proved superior to empiric treatment [OR 2.07 (95% CI 1.53-2.79)]. However, tailored therapy achieved eradication rates >90% in only 15 (44%) studies and >95% in only 6 (17.6%).

CONCLUSIONS

Although tailored therapy performed better than empiric treatment, the lack of optimization of therapies failed to reliably achieve high cure rates (>90%). These results emphasize that H. pylori infection, like other infectious diseases, should utilize the principles of antimicrobial stewardship in relation to treatment guidance.

Disease trends after Helicobacter pylori eradication based on Japanese nationwide claims and the health check-up database

BACKGROUND

Helicobacter pylori (H. pylori) infection is a risk factor for many diseases, including peptic ulcer disease and gastric cancer. While H. pylori eradication therapy can prevent these diseases, potentially unfavorable effects of eradication therapy have also been reported in some diseases, such as gastroesophageal reflux disease (GERD), Barrett’s esophagus (BE), inflammatory bowel disease (IBD), allergic diseases, and metabolic diseases. Consequently, both positive and negative impacts should be considered when assessing the effects of H. pylori eradication therapy.

AIM

To compare the incidence of these diseases before and after H. pylori eradication and to comprehensively assess its effects.

METHODS

This retrospective cohort study used a Japanese nationwide health claims database (April 2009-March 2020), developed by the Japanese Ministry of Health, Labour and Welfare. The database contained almost all health insurance claims data issued in Japan, and specific health check-up data for individuals who took the check-ups. Descriptive statistics were used for the analyses. Patients who received primary eradication therapy were defined as those prescribed medi-cation for H. pylori eradication. New diagnoses, defined as incidence of upper gastrointestinal diseases and IBD, and prevalence of allergic diseases were compared before and after eradication. The incidence and prevalence of each disease were also compared between the 3-year period before eradication (from the 4^th to the 2^nd year prior to the year of eradication) and the 3-year period after eradication (from the 1^st to the 3^rd year after the year of eradication) based on the age category and calendar year and month. Changes in body mass index and proportion of patients with metabolic syndrome (MS) were examined before and after eradication.

RESULTS

We identified 5219731 patients who received primary eradication therapy. The 65-69 years age group had the greatest number of patients in both sexes. There was no significant increase in the incidence of GERD after eradication when considering the effects of aging and reporting period. However, the incidence of BE was higher in the 3-year period after eradication than in the 3-year period before eradication for all age categories (0.02%-0.10% vs < 0.01%-0.05%). The incidence of IBD and prevalence of allergic disease were also higher after eradication. In contrast, the incidence of gastric and duodenal ulcers and gastritis was reduced after eradication. In patients with at least one entry of health check-up data (1701111 patients), the percentage of patients with MS showed a slight increase following eradication (11.0% in the year of eradication and 12.2% after 5 years).

CONCLUSION

The results suggest that H. pylori eradication therapy reduces peptic ulcers and gastritis; however, it is associated with increased incidence of several other chronic diseases.

Endoscopic findings in the upper gastrointestinal tract in patients with Crohn's disease are common, highly specific, and associated with chronic gastritis

Crohn's disease (CD) may affect the entire gastrointestinal tract including its upper part. However, this aspect is poorly addressed in scientific literature and considered a rare finding. Here we aimed to prospectively investigate the prevalence, characteristics and clinical significance of upper gastrointestinal tract involvement in patients with CD, with particular focus on stomach bamboo joint-like appearance (BJA), Helicobacter pylori status and presence of microscopic changes. 375 prospectively recruited patients were included. In CD patients the prevalence of gastric and duodenal, but not esophageal, mucosal lesions, such as gastric mucosal inflammation, duodenal edema, ulcerations, and duodenal bulb deformation was significantly higher (at least p < 0.01 for all). Similar results were found when only H. pylori negative individuals were analyzed. Moreover, BJA of the stomach and in case of H. pylori negative patients also duodenal bulb deformation were detected exclusively in CD patients. Presence of BJA lesion was not significantly associated with neither duration of the disease nor use/history of biologic treatment. Despite absence of H. pylori infection microscopic features of chronic gastritis were found in almost all (93.5%) patients, and in 31% of controls (p < 0.00001). Our analysis outlines that upper gastrointestinal tract involvement in CD is a very common event and frequently manifests with a highly specific BJA lesion. Furthermore, our study reveals that in almost all CD patients features of H. pylori negative gastritis are present.

Helicobacter pylori infection in patients with inflammatory bowel diseases: a single-centre, prospective, observational study in Egypt

OBJECTIVE

Conflicting results have been reported by numerous epidemiological studies investigating the association between Helicobacter pylori (H. pylori) infection and inflammatory bowel disease (IBD). We aimed in this study to assess the possible association between H. pylori infection and IBD and its effects on disease progression.

DESIGN

Prospective observational study.

SETTING

Specialised IBD care clinics at Alexandria University Student Hospital in northern Egypt, between March and June 2019.

PARTICIPANTS

182 patients with IBD.

ANALYSIS AND OUTCOME MEASURES

Participants with IBD were screened for H. pylori infection and clinically evaluated at the initial visit and bimonthly for 3 months to record any potential improvement/flare of the IBD condition.

RESULTS

Overall, 90 (49.5%) patients with IBD had evidence of H. pylori infection. The course of IBD did not significantly differ in association with H. pylori infection or IBD treatment strategy. Cox regression analysis revealed that patients aged 20-35 years (HR=6.20 (95% CI: 1.74 to 22.12)) and 35-55 years (557.9 (17.4-17 922.8)), high socioeconomic status (2.9 (1.11-7.8)), daily consumption of fibre-rich food (5.1 (1.32-19.5)), occasional consumption of snacks between meals (2.8 (2.5-70.5)) and eating four meals per day (13.3 (1.0-7.7)) were predictive of IBD flare. By contrast, eating fruits and vegetables showed a strongly protective association (HR=0.001 (95% CI: 0.0002 to 0.02)). The probabilities of improvement of IBD symptoms after 12 weeks of follow-up were comparable in assessments based on H. pylori infection status (0.793 for H. pylori negative vs 0.778 for H. pylori positive) and IBD treatment option (0.811 for conventional therapy vs 0.750 for biological therapy).

CONCLUSION

The association between IBD and H. pylori infection is unresolved and should be further investigated in the context of specific environmental exposures that can influence the development or relapse of IBD.

Helicobacter Pylori and Autoimmune Diseases: Involving Multiple Systems

The modern Gastroenterology have witnessed an essential stride since Helicobacter pylori was first found in the stomach and then its pathogenic effect was discovered. According to the researches conducted during the nearly 40 years, it has been found that this bacterium is associated with a natural history of many upper gastrointestinal diseases. Epidemiological data show an increased incidence of autoimmune disorders with or after infection with specific microorganisms. The researches have revealed that H. pylori is a potential trigger of gastric autoimmunity, and it may be associated with other autoimmune diseases, both innate and acquired. This paper reviews the current support or opposition about H. pylori as the role of potential triggers of autoimmune diseases, including inflammatory bowel disease, autoimmune thyroiditis, type 1 diabetes mellitus, autoimmune liver diseases, rheumatoid arthritis, idiopathic thrombocytopenic purpura, systemic lupus erythematosus, as well as Sjogren’s syndrome, chronic urticaria and psoriasis, and tried to explain the possible mechanisms.

Systematic review with meta-analysis: environmental and dietary differences of inflammatory bowel disease in Eastern and Western populations

BACKGROUND

While the incidence of inflammatory bowel disease (IBD) has stabilised in the West, it is still increasing in several newly industrialised countries.

AIMS

To investigate whether the environmental and dietary risk factors for IBD differ between Eastern and Western populations METHODS: We systematically searched PubMed, Embase, and Web of Science for studies published from inception through June 30, 2020. Data were pooled using a random effects model.

RESULTS

Overall, 255 studies were assessed. We identified 25 risk factors for IBD, seven of which were noted in both Eastern and Western populations: family history of Crohn's disease [CD] or ulcerative colitis [UC], former smoking (CD/UC), smoking (CD), appendicectomy (CD), tonsillectomy (CD), meat and meat products (CD), and vitamin D deficiency (UC). The remaining factors, including urban living, current smoking, antibiotics, oral contraceptives, caesarean section, isotretinoin, total energy, fat, cholesterol, fatty acids and their sub-classifications, eggs, and soft drinks, were associated with an increased risk of IBD in Western or Eastern populations only. We identified 21 protective factors for IBD, among which eight were common in the East and West: farm animals (CD/UC), Helicobacter pylori infection (CD/UC), multiple births (CD), physical activity (CD), history of breastfeeding (CD), pets (UC), current smoking (UC), and coffee intake (UC). Ten factors conferred protection against IBD in Western populations only, whereas eight factors conferred protection against IBD in Eastern populations only.

CONCLUSIONS

Numerous environmental and dietary factors influenced the development of IBD in both Western and Eastern populations, whereas certain factors influenced IBD risk differently in these populations.

Association between ulcerative colitis and Helicobacter pylori infection: A case-control study

Introduction

Ulcerative Colitis (UC), a type of inflammatory bowel disease (IBD), is defined as chronic inflammation of the superficial mucosal layer of the large intestine. In this study, we aimed to investigate the association between Helicobacter pylori (H. pylori) colonization, and UC in Palestine.

Methods

A total of 35 Palestinian patients of UC and 105 age-matched and gender-matched controls were retrospectively studied for a period of one year. Diagnosis of ulcerative colitis was based on both colonoscopy and biopsy. The presence of H. pylori in the stomach was evaluated by the H. pylori stool antigen test (HpSA). An interview-based data collection form was filled for all patients with UC before starting the test.

Results

The overall positivity of H. pylori infection in patients with UC was 14.3%, significantly lower than the control group, 41.9% (odds ratios (OR) = 0.23, 95% confidence intervals (CI): 0.083–0.643, P-value = 0.003). Interestingly, the presence of H. pylori showed no correlation with the extension of UC (P-value = 0.44). Moreover, there were no relationships between the presence of H. pylori and age (P-value = 0.97), gender (P-value = 0.26), smoking (P-value = 0.08), and medication regimen (P-value = 0.80).

Conclusion

The rate of H. pylori infection was significantly lower in patients with UC compared with the control group suggesting a protective role of H. pylori against the occurrence of UC.

Is the Presence of Helicobacter Pylori in the Colonic Mucosa, Provocative of Activity in Ulcerative Colitis?

Background:

Epidemiologic studies have shown world-wide increasing incidence of ulcerative colitis (UC) as an autoimmune disease of intestine. In the meantime, gastrointestinal H. Pylori infection is being decreased.

Objectives:

There are very few studies about comparing the presence of H. Pylori in the colon and the disease activity of UC. There is no study form Iran. In this study, we tried to investigate the presence of H. Pylori in the mucosa of colon by molecular and microbiological as well as pathological methods to find any association between the presence of this organism in the colon and the presence and activity of UC.

Patients and Methods:

In 100 patients who referred to colonoscopy clinic, colonoscopy was performed. Fifty-seven patients with the new diagnosis of UC were considered as cases and 43 patients with normal screening colonoscopy for polyps were considered as controls. Colon biopsies were evaluated according to histopathology, clinical findings, and laboratory results to confirm the diagnosis and the degree of activity in the cases of UC. Molecular studies were also performed to evaluate the presence of H. Pylori genome in the colon biopsies. A sample of colon was also cultured for H. Pylori. ELISA test was performed in a sample of blood to evaluate the level of IL-10 and IL-17 as regulatory cytokines of inflammation.

Results:

Cases with the diagnosis of UC showed significantly higher number of positive colonic H. Pylori comparing to normal colonic mucosa. Also, the presence of H. Pylori genome in the colon was associated with higher activity in the cases with UC and higher levels of inflammatory mediators especially IL17 and lower levels of inhibitory mediators such as IL-10.

Conclusion:

Colonic colonization of H. Pylori was higher in the patients with UC and higher activity of this disease comparing with normal control colonic mucosa.

Progress in elucidating the relationship between Helicobacter pylori infection and intestinal diseases

Helicobacter pylori (H. pylori) infection causes changes to the intestinal flora, such as small intestinal bacterial overgrowth, and increases gastric acid secretion-stimulating gastrointestinal hormones, mainly gastrin, due to a decrease in gastric acid caused by atrophic gastritis. In addition, the cellular components of H. pylori travel through the intestinal tract, so the bacterial infection affects the immune system. Therefore, the effects of H. pylori infection are observed not only in the stomach and the proximal duodenum but also in the small and large intestines. In particular, meta-analyses reported that H. pylori-infected individuals had an increased risk of colorectal adenoma and colorectal cancer. Moreover, a recent study reported that the risk of developing colorectal cancer was increased in subjects carrying H. pylori vacuolating cytotoxin A antibody. In addition, it has been reported that H. pylori infection exacerbates the symptoms of Fabry’s disease and familial Mediterranean fever attack and is involved in irritable bowel syndrome and small intestinal ulcers. On the other hand, some studies have reported that the frequency of ulcerative colitis, Crohn’s disease, and celiac disease is low in H. pylori-infected individuals. Thus, H. pylori infection is considered to have various effects on the small and large intestines. However, few studies have reported on these issues, and the details of their effects have not been well elucidated. Therefore, additional studies are needed.

Evaluation of an attenuated Listeria monocytogenes as a vaccine vector to control Helicobacter pylori infection

The increasing resistance of Helicobacter pylori (H. pylori) to antibiotics has limited the efficacy of antibiotic therapy in the treatment of H. pylori-associated gastric diseases. The vaccine as an alternative method is becoming a safe and effective way to address this problem. In previous studies, live vector vaccines have proved to be effective in controlling H. pylori infection. Attenuated Listeria monocytogenes (L. monocytogenes) is a potential candidate vector applied in clinical trials, which can deliver foreign antigens and induce a broad immune response. To further explore the effectiveness of L. monocytogenes as a vaccine vector against H. pylori, attenuated L. monocytogenes-based vaccine EGDeΔactA/inlB(EGDeAB)-MECU was constructed to secrete a multi-epitope chimeric antigen (MECU) containing multiple B cell epitopes from H. pylori antigens. EGDeAB-MECU could secrete MECU stably. After immunized by gavage and intravenous injection, both EGDeAB and EGDeAB-MECU could significantly decrease gastric H. pylori colonization and induce a high level of specific antibodies against H. pylori. In conclusion, attenuated L. monocytogenes had an immunotherapeutic effect on H. pylori-infected mice, indicating its further development as a promising candidate vaccine vector for the H. pylori vaccine.

Helicobacter pylori infection causes both protective and deleterious effects in human health and disease

Infection with Helicobacter pylori (H. pylori) is necessary but not sufficient for the development of gastric cancer, the third leading cause of cancer death globally. H. pylori infection affects over half of people globally; however, it does not affect populations uniformly. H. pylori infection rates are declining in western industrialized countries but are plateauing in developing and newly industrialized countries where gastric cancer is most prevalent. Despite H. pylori infection being the primary causative agent for gastric cancer, H. pylori infection can also cause other effects, detrimental or beneficial, throughout an individual's life, with the beneficial effects often being seen in childhood and the deleterious effects in adulthood. H. pylori is an ancient bacterium and its likelihood of affecting disease or health is dependent on both human and bacterial genetics that have co-evolved over millennia. In this review, we focus on the impact of infection and its genetic bases in different populations and diseases throughout an individual's lifespan, highlighting the benefits of individualized treatment and argue that universal eradication of H. pylori in its host may cause more harm than good for those infected with H. pylori.

Comparative Effectiveness of Multiple Different First-Line Treatment Regimens for Helicobacter pylori Infection: A Network Meta-analysis

BACKGROUND & AIMS

A number of double, triple, and quadruple therapies have been proposed as first-line empiric treatments for Helicobacter pylori infection. However, knowledge of their worldwide and regional comparative efficacy is lacking. We examined the comparative effectiveness of all empirically used first-line regimens tested against standard triple treatment using a network meta-analysis of published randomized controlled trials.

METHODS

Data extracted from eligible randomized controlled trials were entered into a Bayesian network meta-analysis to investigate the comparative efficacy of H pylori infection empiric first-line regimens and to explore their effectiveness rank order. The ranking probability for each regimen was evaluated by means of surfaces under cumulative ranking values.

RESULTS

Sixty-eight eligible randomized controlled trials were included, giving a total of 92 paired comparisons with 22,975 patients randomized to 8 first-line regimens. The overall results showed that only vonoprazan triple therapy and reverse hybrid therapy achieved cure rates of >90%. Levofloxacin triple therapy performed best in Western countries (eradication rate 88.5%). The comparative effectiveness ranking showed that vonoprazan triple therapy had the best results, whereas standard triple therapy was the least efficacious regimen (surfaces under cumulative ranking 92.4% vs 4.7% respectively; odds ratio, 3.80; 95% credible interval, 1.62-8.94).

CONCLUSIONS

For first-line empiric treatment of H pylori infection, vonoprazan triple therapy and reverse hybrid therapy achieved high eradication rates of >90%. Levofloxacin triple therapy achieved the highest eradication rates in Western countries. Standard triple therapy was the least efficacious regimen in this network meta-analysis.

Inverse Association Between Helicobacter pylori Infection and Unexplained Isolated Terminal Ileitis: A Retrospective Study

Background

Isolated terminal ileitis (ITI) is a phenomenon often observed during colonoscopy, but in most cases, the specific etiology of ITI is unclear. Helicobacter pylori (H. pylori) infection has been reported to be associated with a wide variety of diseases, especially gastrointestinal diseases. Here, we conducted a retrospective study to explore a potential correlation between H. pylori infection and unexplained ITI (UITI).

Materials and Methods

The retrospective study was conducted at Sino-French New City Branch of Tongji Hospital, Wuhan, China, from April 2017 to October 2020. All subjects underwent total colonoscopy, with the endoscope being inserted more than 10cm into the terminal ileum. Subjects also received a ¹³C-urea breath test (¹³C-UBT). Data on the age, gender, endoscopic manifestations, and main clinical symptoms of subjects were collected. The presence of H. pylori infection was defined as a positive ¹³C-UBT result. Logistic regression models were used to analyze the potential correlation between H. pylori infection and UITI.

Results

There were 247 subjects (25.1%) in the H. pylori (+) group and 739 subjects (74.9%) in the H. pylori (-) group. The prevalence of UITI in the H. pylori (+) group was significantly lower than that in the H. pylori (-) group (OR = 0.518; 95% CI 0.281-0.956; P = 0.035), and there was no difference in other clinical features between groups. Stratification analysis results showed that there was an inverse association between H. pylori infection and UITI in subjects with age <60 (P = 0.046).

Conclusion

These data showed that H. pylori infection was negatively correlated with UITI. Additional studies are needed to validate these findings in a larger cohort as well as to explore the underlying mechanisms.

Comparative effectiveness of 5-hydroxytryptamine 3 receptor antagonists in irritable bowel syndrome: a network meta-analysis of randomized controlled studies

BACKGROUND

There is evidence demonstrating the beneficial effects of 5-hydroxytryptamine 3 receptor antagonists (5-HT3) for the treatment of non-constipated irritable bowel syndrome (NC-IBS). We aimed to determine the comparative effectiveness of 5-HT3 antagonists in NC-IBS, as evidenced by the results of a network meta-analysis (NWM) of published relevant randomized controlled trials (RCTs).

METHODS

We searched the PubMed/Medline, EMBASE, and Cochrane Library databases for relevant RCTs through September 2020 and data from each selected RCT were extracted. A Bayesian NWM was then performed to investigate the efficacy of 5-HT3 antagonists and to explore the effectiveness rank order in treating NC-IBS patients.

RESULTS

Twenty-one eligible RCTs were identified and entered into this NWM. They included a total of 10,421 NC-IBS patients, randomized to alosetron, cilansetron, ondansetron, ramosetron, placebo, and mebeverine. The cumulative ranking probability for each intervention at the end of treatment period, was evaluated by means of surfaces under cumulative ranking (SUCRA) values. These results showed that alosetron had the best performance for global symptom improvement (SUCRA 0.82), cilansetron showed the best performance (SUCRA 0.90) for abdominal pain/discomfort improvement, while ondansetron (SUCRA 0.98) was by far the best choice concerning bowel habits/consistency improvement. The control regimens (mebeverine and placebo) represented the least efficacious interventions.

CONCLUSIONS

This NWM showed that 5-HT3 receptor antagonists performed better in comparison to control drugs. Consequently, this class of drugs may play an important role in improving the debilitating symptoms in NC-IBS patients, in particular those with diarrhea.

A Network Meta-Analysis of Randomized Controlled Trials on the Treatment of Eosinophilic Esophagitis in Adults and Children

BACKGROUND

Network meta-analysis is used as a data synthesizer, incorporating direct and indirect evidence about treatments in a series of randomized control trials.

OBJECTIVE

To evaluate the comparative efficacy of various treatments for eosinophilic esophagitis (EoE).

METHODS

We performed a network meta-analysis to combine direct and indirect data to investigate the efficiency of drug therapies, which were evaluated in relevant randomized control trials for EoE.

RESULTS

Seventeen eligible studies (14 two-arm and 3 multiple-arm) were introduced to the meta-analysis. A total of 1011 patients were included, in whom 15 therapeutic interventions were used, namely: (1) budesonide oral suspension, (2) budesonide 1 mg orodispersible tablet twice daily, (3) budesonide 2 mg orodispersible tablet twice daily, (4) esomeprazole, (5) fluticasone, (6) nebulized steroid, (7) placebo, (8) prednisone, (9) anti-IL-5-mab (mepolizumab), (10) anti-IL-5-mab [reslizumab(1), ie, 1 mg/kg], (11) anti-IL-5-mab [reslizumab(2), ie, 2 mg/kg], (12) anti-IL-5-mab [reslizumab(3), ie, 3 mg/kg], (13) anti-IL-13-mab (QAX 576), (14) anti-IL-13-mab [RCP 4046 (180)], and (15) anti-IL-13-mab [RCP 4046 (360)]. Budesonide 1 mg orodispersible tablet twice daily showed the highest efficacy (SUCRA 0.91), whereas placebo was the least effective. In adult patients budesonide 1 mg orodispersible tablet twice daily remained the optimal treatment approach, whereas the corresponding therapeutic approach in pediatric patients was fluticasone.

CONCLUSIONS

This meta-analysis showed that budesonide 1 mg orodispersible tablet twice daily was the best treatment for EoE, as it was the most effective. This treatment remained the optimal approach in adult patients, whereas fluticasone was the best treatment in pediatric patients.

The Roles of IL-17, IL-21, and IL-23 in the Helicobacter pylori Infection and Gastrointestinal Inflammation: A Review

Although millions of people have been infected by Helicobacter pylori (H. pylori), only a small proportion of infected individuals will develop adverse outcomes, ranging from chronic gastritis to gastric cancer. Advanced development of the disease has been well-linked with chronic inflammation, which is significantly impacted by the adaptive and humoral immunity response. From the perspective of cellular immunity, this review aims to clarify the intricate axis between IL-17, IL-21, and IL-23 in H. pylori-related diseases and the pathogenesis of inflammatory gastrointestinal diseases. CD4⁺ helper T (Th)-17 cells, with the hallmark pleiotropic cytokine IL-17, can affect antimicrobial activity and the pathogenic immune response in the gut environment. These circumstances cannot be separated, as the existence of affiliated cytokines, including IL-21 and IL-23, help maintain Th17 and accommodate humoral immune cells. Comprehensive understanding of the dynamic interaction between molecular host responses in H. pylori-related diseases and the inflammation process may facilitate further development of immune-based therapy.

The role of gastrointestinal pathogens in inflammatory bowel disease: a systematic review

The inflammatory bowel diseases (IBD), comprising Crohn's disease (CD) and ulcerative colitis (UC), are chronic, progressive, inflammatory conditions of the gastrointestinal tract. Imbalance in the gut microbial community, or dysbiosis, and the subsequent immune response, represent the critical relationship between genetic susceptibility, microbes, and environment factors, that result in IBD. Gastrointestinal pathogens - a common cause of dysbiosis - have been implicated as an environmental trigger in new onset IBD, as well as flare of existing IBD. In this article, we systematically review clinical data regarding the association between specific gastrointestinal pathogens and IBD. Numerous bacteria, viruses, fungi, and parasites have been implicated in the pathogenesis of IBD, and exacerbations of existing disease. In this article, we will also specifically discuss the less recognized microbes that have an inverse association with IBD, including certain bacterial pathogens, such as Helicobacter pylori, and parasites, such as Trichuris species. Future prospective and experimental studies are required to establish causality and clarify potential mechanisms of enteric pathogens in modifying the risk and course of IBD.

Helicobacter pylori: Commensal, symbiont or pathogen?

This review considers the data on Helicobacter pylori (H. pylori), which have been accumulated over 40 years since its description as an etiological factor in gastrointestinal diseases. The majority of modern publications are devoted to the study of the pathogenic properties of the microorganism in the development of chronic gastritis, peptic ulcer disease, and gastric cancer, as well as methods for its eradication. However, in recent years, there have been more and more studies which have suggested that H. pylori has a beneficial, or potentially positive, effect on the human body. The authors have attempted to objectively analyze the information accumulated in the literature on H. pylori. Some studies consider it as one of the recently identified human bacterial pathogens, and special attention is paid to the evidence suggesting that it is probably part of the composition of the human microbiome as a commensal (commensal from French to English is a table companion) or even a symbiont. The presented data discussing the presence or absence of the effect of H. pylori on human health suggest that there is an apparent ambiguity of the problem. The re-assessment of the data available on H. pylori infection is important in order to answer the question of whether it is necessary to create a program of mass H. pylori eradication or to apply a more personalized approach to treating patients with H. pylori-associated gastrointestinal diseases and to perform eradication therapy.

Anti-Inflammatory Effects of Heritiera littoralis Fruits on Dextran Sulfate Sodium- (DSS-) Induced Ulcerative Colitis in Mice by Regulating Gut Microbiota and Suppressing NF-κB Pathway

Materials and Methods

The chemical compositions of EFH were identified using LC-ESI-MS. The mice with 3% DSS-induced UC were administered EFH (200, 400, and 800 mg/kg), sulfasalazine (SASP, 200 mg/kg), and azathioprine (AZA, 13 mg/kg) for 10 days via daily gavage. The colonic inflammation was evaluated by the disease activity index (DAI), colonic length, histological scores, and levels of inflammatory mediators. The gut microbiota was characterized by 16S rRNA gene sequencing and analysis.

Results

LC-ESI-MS analysis showed that EFH was rich in alkaloids and flavones. The results indicated that EFH significantly improved the DAI score, relieved colon shortening, and repaired pathological colonic variations in colitis. In addition, proteins in the NF-κB pathway were significantly inhibited by EFH. Furthermore, EFH recovered the diversity and balance of the gut microbiota.

Conclusions

EFH has protective effects against DSS-induced colitis by keeping the balance of the gut microbiota and suppressing the NF-κB pathway.

Review - Helicobacter pylori and non-malignant upper gastro-intestinal diseases

This review takes into account recent publications focusing on the relationship between Helicobacter pylori infection and non-malignant diseases of the upper gastro-intestinal tract. The authors have summarized current knowledge on associations between the H pylori infection and non-malignant upper GI conditions including gastroesophageal reflux disease (GERD), Barrett's esophagus, eosinophilic esophagitis (EOE), peptic ulcer disease (PUD), H pylori gastritis, celiac disease and functional dyspepsia. In the field of GERD, current data focusing on different locations of H pylori infection detect significant differences between antrum- and corpus predominant gastritis explainable by different changes in acid secretion in different gastric niches. High volume studies from Sweden and Brazil underline the safety of H pylori eradication concerning the risk of Barret's esophagus or adenocarcinoma. The relationship betweenH pylori infection and EOE remains uncertain, but current data supports the concept of expected positive and protective effects of H pylori exposure reducing the risk of EOE. Analyzing biomarkers might be helpful to identify subjects under risk for the development of precancerous lesions after H pylori infection, where microRNAs, IL-9 and IL-4, and also Tc17/9 and Th17/9 and microbiota profiles showed promising results to identify subgroups under risk.

Review: Extragastric diseases and Helicobacter pylori

The involvement of Helicobacter pylori infection in many extra-gastroduodenal manifestations remains a fascinating field of investigation. However, for several of these supposed associations, the potential pathogenic mechanism remains unclear. The present review highlights the main associations of H pylori with extra-gastroduodenal manifestations reported during the last year. We searched for the most relevant studies on this topic, published between April 2019 and March 2020, identified using the term "Helicobacter" in the MEDLINE/Pubmed database. Consistent data emerged from studies investigating metabolic syndrome and ischaemic cardiovascular diseases. Other reported fields of investigation were hepatology, especially focused on non-alcoholic steatohepatitis, neurology, including Parkinson's disease and Alzheimer's disease, as well as dermatology. Inflammatory bowel disease (IBD), that comprises Crohn's disease and ulcerative colitis, may originate from a dysregulation of the host's immune response to commensal bacteria in individuals with genetic predisposition. The reduction of biodiversity and other specific imbalances in the faecal microbiome composition of IBD patients compared to that of healthy controls support this hypothesis. In this context, an inverse correlation between H pylori infection and IBD prevalence has been confirmed. Similar results were found in patients with kidney diseases and allergic manifestations. There are indications of the possible involvement of H pylori infection in metabolic syndrome and ischaemic cardiovascular diseases. However, due to a series of factors linked to study designs and the multifactorial pathogenesis of some diseases, further studies are needed.

Reconsidering the "protective" hypothesis of Helicobacter pylori infection in eosinophilic esophagitis

Since its discovery, Helicobacter pylori (H. pylori) has attracted attention in the biomedical world with its numerous pathophysiologic implications, both gastrointestinal and systemic. Beyond its well-established carcinogenic properties, emerging evidence also supports "harmful" proinflammatory and neurodegenerative roles of H. pylori. On the other hand, H. pylori infection has been proposed to be "protective" against several diseases, such as asthma and gastroesophageal reflux disease. Eosinophilic esophagitis (EoE) is a relatively new, allergen/immune-mediated disease, which has also been linked to these considerations. Main arguments are a postulated shift of immune responses by H. pylori from T helper 2 (T_H 2) to T_H 1 polarization, as well as a potential decline of the H. pylori burden with the dramatic parallel rise of ΕοΕ: a series of observational studies reported an inverse association. In this review, we counter these arguments by providing further epidemiological data, which point out that this generalization might be rather incomplete. We also discuss the limitations of the existing studies evaluating a possible association. Furthermore, we provide current evidence on common pathogenetic components, which share both entities. In summary, the claim that H. pylori is protective against EoE is rather incomplete, and further mechanistic studies are necessary to elucidate a possible association.

Synthesis of Interleukin-10 in Patients with Ulcerative Colitis and Helicobacter pylori Infection

METHODS

Detection of H. pylori infection was performed by a 13C-urea breath test in 31 patients with UC. In each patient, a serum sample was drawn to measure IL-10 by the ELISA technique. Based on the primary breath test result, two groups were formed and serum IL-10 was measured.

RESULTS

Serological IL-10 levels in patients with UC and negative 13C-urea breath test was 10.28 pg/ml whereas in patients with UC and positive 13C-urea breath test was 5.5 pg/ml (P = 0.035). IL-10 levels were higher in the inflammatory endoscopic and histological active groups which tested positive in the 13C-urea breath tests for H. pylori (P < 0.05).

CONCLUSIONS

The role of IL-10 secretion in patients with UC in determining the clinicopathological outcome of infection merits further study. This study suggests an association between serum IL-10 and disease severity in patients with UC and HP infection.

The microbiome in inflammatory bowel diseases: from pathogenesis to therapy

Inflammatory bowel disease (IBD) has become a global disease with accelerating incidence worldwide in the 21st century while its accurate etiology remains unclear. In the past decade, gut microbiota dysbiosis has consistently been associated with IBD. Although many IBD-associated dysbiosis have not been proven to be a cause or an effect of IBD, it is often hypothesized that at least some of alteration in microbiome is protective or causative. In this article, we selectively reviewed the hypothesis supported by both association studies in human and pathogenesis studies in biological models. Specifically, we reviewed the potential protective bacterial pathways and species against IBD, as well as the potential causative bacterial pathways and species of IBD. We also reviewed the potential roles of some members of mycobiome and virome in IBD. Lastly, we covered the current status of therapeutic approaches targeting microbiome, which is a promising strategy to alleviate and cure this inflammatory disease.

The role of the changing human microbiome in the asthma pandemic

Asthma and allergy incidence continue to increase globally. We have made significant strides in treating disease, but it is becoming more apparent that we need to advance our knowledge into the origins of asthmatic disease. Much recent work has indicated that microbiome composition influences immune regulation and that multiple health care factors have driven a loss in microbiome diversity in modern human populations. Evidence is growing of microbiota-driven influences on immune development, asthma susceptibility, and asthma pathogenesis. The focus of this review is to highlight the strides the field has made in characterizing the constituents of the human gastrointestinal microbiota, such as Helicobacter pylori, other members of the neonatal intestinal microbiota, and microbial peptides and metabolites that influence host immunity and immune response to allergens. As we delve further into this field of research, the goal will be to find actionable and clinical interventions to identify at-risk populations earlier to prevent disease onset. Manipulation of the host microbial community during infancy might be an especially promising approach.

Systematic review: gastrointestinal infection and incident inflammatory bowel disease

BACKGROUND

The initiating events of chronic gastrointestinal (GI) inflammation in Crohn's disease (CD) and ulcerative colitis (UC) are not well-defined, but GI infections are implicated.

AIMS

To define the role of GI infections in risk of incident inflammatory bowel disease (IBD) and synthesise the current body of relevant translational data to provide biological context for associations between GI infections and IBD risk.

METHODS

We systematically reviewed electronic databases through February 2020. Clinical studies that provided risk estimates of the association between GI infections and incident IBD were included. Inclusion criteria were broader for translational studies aiming to define mechanisms of GI infections and predisposition to or protection from IBD.

RESULTS

Of the studies identified, 63 met full inclusion criteria. Among studies of clinical gastroenteritis, bacteria-specifically, Salmonella species, Campylobacter species and Clostridioides difficile-demonstrated consistent positive associations with risk of incident IBD. Of viruses, norovirus was associated with increased risk of incident CD. Regarding inverse associations with incident IBD, Helicobacter pylori and helminth infections were associated with a generally consistent reduced risk of IBD. Based on a qualitative analysis of the translational data, putative mechanisms involve multiple microbial and immunologic pathways.

CONCLUSIONS

Based on this systematic review, certain enteric pathogens are associated with an increased risk of incident IBD, while others are potentially protective. Prospective studies are required to clarify the clinical implications of these enteric pathogens on the risk and course of IBD, and possible therapeutic or preventative benefit.

Systematic review: gastric microbiota in health and disease

BACKGROUND

Helicobacter pylori is the most infamous constituent of the gastric microbiota and its presence is the strongest risk factor for gastric cancer and other gastroduodenal diseases. Although historically the healthy stomach was considered a sterile organ, we now know it is colonised with a complex microbiota. However, its role in health and disease is not well understood.

AIM

To systematically explore the literature on the gastric microbiota in health and disease as well as the gut microbiota after bariatric surgery.

METHODS

A systematic search of online bibliographic databases MEDLINE/EMBASE was performed between 1966 and February 2019 with screening in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Randomised controlled trials, cohort studies and observational studies were included if they reported next-generation sequencing derived microbiota analysis on gastric aspirate/tissue or stool samples (bariatric surgical outcomes).

RESULTS

Sixty-five papers were eligible for inclusion. With the exception of H pylori-induced conditions, overarching gastric microbiota signatures of health or disease could not be determined. Gastric carcinogenesis induces a progressively altered microbiota with an enrichment of oral and intestinal taxa as well as significant changes in host gastric mucin expression. Proton pump inhibitors usage increases gastric microbiota richness. Bariatric surgery is associated with an increase in potentially pathogenic proteobacterial species in patient stool samples.

CONCLUSION

While H pylori remains the single most important risk factor for gastric disease, its capacity to shape the collective gastric microbiota remains to be fully elucidated. Further studies are needed to explore the intricate host/microbial and microbial/microbial interplay.

Deficiency of Gankyrin in the small intestine is associated with augmented colitis accompanied by altered bacterial composition of intestinal microbiota

Background

Gankyrin (GK) is an oncoprotein which regulates inflammatory responses and its inhibition is considered as a possible anti-inflammatory therapy for inflammatory bowel disease (IBD).

Methods

In this study, we investigated the role of GK in epithelial cells using mice with intestinal epithelial cell-specific GK deletion in (i) the entire small intestine and colon (Villin-Cre;Gankyrin^f/f) and (ii) the distal intestine and colon (Cdx2-Cre;Gankyrin^f/f).

Result

Unexpectedly, GK-deficiency in the upper small bowel augmented inflammatory activity compared with control mice when colitis was induced with dextran sodium sulfate. Biochemical analyses have revealed GK-deficiency to have caused reduction in the expression of antimicrobial peptides, α-Defensin-5 and -6, in the upper small bowel. Examination of human samples have further confirmed that the reduction of GK expression in the small bowel is associated with colonic involvement in human Crohn’s disease. Through the sequencing of bacterial 16S rRNA gene amplicons, bacteria potentially deleterious to intestinal homeostasis such as Helicobacter japonicum and Bilophila were found to be over-represented in colitis induced Villin-Cre;Gankyrin^f/f mice when compared to Gankyrin^f/f control mice under the same condition.

Conclusion

These results highlight the distinct site dependence of the pro- and anti-inflammatory functions of GK and provide important insights into the pathogenesis of IBD.

Hellenic consensus on Helicobacter pylori infection

The Hellenic Society of Gastroenterology recently organized the “Hellenic consensus on Helicobacter pylori (H. pylori) infection”. The aim of this publication is to report the guidelines in order to aid the national gastroenterology community in the management of H. pylori infection. Forty-one delegates from all Greek regions, including gastroenterologists, pathologists, clinical microbiologists, epidemiologists and basic scientists, were invited to this meeting. The participants were allocated to 1 of the 4 main topics of the meeting: i.e., H. pylori diagnosis and association with diseases; H. pylori and gastric cancer; H. pylori and extragastric associated disorders; and H. pylori treatment. The results of each subgroup were submitted to a final consensus vote that included all participants. Relevant data based on international and Greek publications were presented, and the quality of evidence, strength of recommendation, and level of consensus were graded. The cutoff level of 70% was considered as acceptance for the final statement. It is hoped that the recommendations and conclusions of this report will guide Greek doctors in their daily practice concerning the management of H. pylori infection.

Association Between Helicobacter pylori Exposure and Decreased Odds of Eosinophilic Esophagitis-A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Previous or current infection with Helicobacter pylori (exposure) has been reported to protect against eosinophilic esophagitis (EoE), perhaps owing to H pylori-induced immunomodulation. However, findings vary. We performed a systematic review and meta-analysis of comparative studies to define the association between H pylori exposure and EoE more clearly.

METHODS

We searched 4 large databases to identify comparative clinical studies that included sufficient detail to determine the odds or risk of EoE (primary outcome) or esophageal eosinophilia (secondary outcome) among individuals exposed to H pylori (exposed) vs individuals who were tested and found to be unexposed. Estimates were pooled using a random-effects model. Meta-regression and sensitivity analyses were planned a priori. Studies were evaluated for quality, risk of bias, publication bias, and heterogeneity.

RESULTS

We analyzed 11 observational studies comprising data on 377,795 individuals worldwide. H pylori exposure vs nonexposure was associated with a 37% reduction in odds of EoE (odds ratio, 0.63; 95% CI, 0.51-0.78) and a 38% reduction in odds of esophageal eosinophilia (odds ratio, 0.62; 95% CI, 0.52-0.76). Fewer prospective studies found a significant association between H pylori exposure and EoE (P = .06) than retrospective studies. Effect estimates were not affected by study location, whether the studies were performed in pediatric or adult populations, time period (before vs after 2007), or prevalence of H pylori in the study population.

CONCLUSIONS

In a comprehensive meta-analysis, we found evidence for a significant association between H pylori exposure and reduced odds of EoE. Studies are needed to determine the mechanisms of this association.

Environmental Risk Factors for Inflammatory Bowel Diseases: An Umbrella Review of Meta-analyses

BACKGROUND & AIMS

Multiple environmental factors have been associated with the development of inflammatory bowel diseases (IBDs). We performed an umbrella review of meta-analyses to summarize available epidemiologic evidence and assess its credibility.

METHODS

We systematically identified and appraised meta-analyses of observational studies examining environmental factors and risk of IBD (Crohn's disease [CD] or ulcerative colitis [UC]). For each meta-analysis, we considered the random effects estimate, its 95% confidence interval, the estimates of heterogeneity, and small-study effects, and we graded the evidence according to prespecified criteria. Methodologic quality was assessed with AMSTAR (ie, A Measurement Tool to Assess Systematic Reviews) 2.

RESULTS

We examined 183 estimates in 53 meta-analyses of 71 environmental factors related to lifestyles and hygiene, surgeries, drug exposures, diet, microorganisms, and vaccinations. We identified 9 factors that increase risk of IBD: smoking (CD), urban living (CD and IBD), appendectomy (CD), tonsillectomy (CD), antibiotic exposure (IBD), oral contraceptive use (IBD), consumption of soft drinks (UC), vitamin D deficiency (IBD), and non-Helicobacter pylori-like enterohepatic Helicobacter species (IBD). We identified 7 factors that reduce risk of IBD: physical activity (CD), breastfeeding (IBD), bed sharing (CD), tea consumption (UC), high levels of folate (IBD), high levels of vitamin D (CD), and H pylori infection (CD, UC, and IBD). Epidemiologic evidence for all of these associations was of high to moderate strength; we identified another 11 factors associated with increased risk and 16 factors associated with reduced risk with weak credibility. Methodologic quality varied considerably among meta-analyses. Several associations were based on findings from retrospective studies, so it is not possible to determine if these are effects of IBD or the results of recall bias.

CONCLUSIONS

In an umbrella review of meta-analyses, we found varying levels of evidence for associations of different environmental factors with risk of IBD. High-quality prospective studies with analyses of samples from patients with recent diagnoses of IBD are needed to determine whether these factors cause or are results of IBD and their pathogenic mechanisms.

A network meta-analysis of randomized controlled trials exploring the role of fecal microbiota transplantation in recurrent Clostridium difficile infection

Background

Recurrence remains a challenge in Clostridium difficile infection (CDI), and in this field fecal microbiota transplantation (FMT) has attracted significant interest. Network meta-analysis (NWM) has been established as an evidence-synthesis tool that incorporates direct and indirect evidence in a collection of randomized controlled trials. So far no NWM exists concerning therapeutic interventions for recurrent CDI (rCDI).

Objective

In this NWM we assessed the comparative effectiveness of various therapies for rCDI to examine the efficacy rank order and determine the optimum therapeutic approach.

Methods

A Bayesian network meta-analysis was performed to investigate the efficacy rank order of rCDI interventions.

Results

Six eligible RCTs were entered into an NWM. They included 348 rCDI patients, in whom seven therapeutic interventions were used, i.e. donor fecal microbiota transplantation (DFMT), vancomycin, fidaxomicin, vancomycin + DFMT, vancomycin + bowel lavage, autologous FMT and placebo. DFMT showed the highest efficacy in comparison with vancomycin [odds ratio (95% credible interval), 20.02 (7.05-70.03)] and fidaxomicin (22.01 (4.38-109.63)).

Conclusion

This NWM showed that DFMT is the optimum therapeutic approach for rCDI, as it was the most efficacious among various therapeutic interventions, particularly in comparison with commonly used antibiotics such as vancomycin or fidaxomicin.

Identification of differentially expressed genes, associated functional terms pathways, and candidate diagnostic biomarkers in inflammatory bowel diseases by bioinformatics analysis

Inflammatory bowel diseases (IBDs), including ulcerative colitis (UC) and Crohn's disease (CD), are chronic inflammatory disorders caused by genetic influences, the immune system and environmental factors. However, the underlying pathogenesis of IBDs and the pivotal molecular interactions remain to be fully elucidated. The aim of the present study was to identify genetic signatures in patients with IBDs and elucidate the potential molecular mechanisms underlying IBD subtypes. The gene expression profiles of the GSE75214 datasets were obtained from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were identified in UC and CD patients compared with controls using the GEO2R tool. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of DEGs were performed using DAVID. Furthermore, protein-protein interaction (PPI) networks of the DEGs were constructed using Cytoscape software. Subsequently, significant modules were selected and the hub genes were identified. In the GO and KEGG pathway analysis, the top enriched pathways in UC and CD included Staphylococcus aureus infection, rheumatoid arthritis, complement and coagulation cascades, PI3K/Akt signaling pathway and osteoclast differentiation. In addition, the GO terms in the category biological process significantly enriched by these genes were inflammatory response, immune response, leukocyte migration, cell adhesion, response to molecules of bacterial origin and extracellular matrix (ECM) organization. However, several other biological processes (GO terms) and pathways (e.g., ‘chemotaxis’, ‘collagen catabolic process’ and ‘ECM-receptor interaction’) exhibited significant differences between the two subtypes of IBD. The top 10 hub genes were identified from the PPI network using respective DEGs. Of note, the hub genes G protein subunit gamma 11 (GNG11), G protein subunit beta 4 (GNB4), Angiotensinogen (AGT), Phosphoinositide-3-kinase regulatory subunit 3 (PIK3R3) and C-C motif chemokine receptor 7 (CCR7) are disease-specific and may be used as biomarkers for differentiating UC from CD. Furthermore, module analysis further confirmed that common significant pathways involved in the pathogenesis of IBD subtypes were associated with chemokine-induced inflammation, innate immunity, adapted immunity and infectious microbes. In conclusion, the present study identified DEGs, key target genes, functional pathways and enrichment analysis of IBDs, enhancing the understanding of the pathogenesis of IBDs and also advancing the clarification of the underlying molecular mechanisms of UC and CD. Furthermore, these results may provide potential molecular targets and diagnostic biomarkers for UC and CD.

Inverse association between Helicobacter pylori and inflammatory bowel disease: myth or fact?

Background: Inflammatory bowel diseases (IBD), are chronic, relapsing-remitting diseases of the gastrointestinal tract, including Crohn’s disease (CD), Ulcerative colitis (UC) and Unclassified IBD (IBDU). Their pathogenesis involves genes and environment as cofactors in inducing autoimmunity; particularly the interactions between enteric pathogens and immunity is being studied. Helicobacter pylori (HP) is common pathogen causing gastric inflammation. Studies found an inverse prevalence association between HP and IBD, suggesting a potential protecting role of HP from IBD. Methods: A literature search of the PubMed database was performed using the key words‘’helicobacter pylori’’,‘’inflammatory bowel disease’’,‘’crohn disease’’, “ulcerative colitis”. Embase, Medline (OvidSP), Web of Science, Scopus, PubMed publisher, Cochrane and Google Scholar were also searched. Prevalence rate-ratios among HP in IBD patients, HP in CD patients, HP in UC patients, HP in IBDU patients were extracted, each group was compared with controls, to verify the inverse association between HP and IBD prevalence. Results: In all groups the dispersion of data suggested an inverse association between IBD group and controls, even when the comparison was carried out separately between each group of newly diagnosed patients and controls, to rule out the possible bias of ongoing pharmacologic therapy. Conclusions: The results of this review show a striking inverse association between HP infection and the prevalence of IBD, independently from the type of IBD considered across distinct geographic regions. Anyway, data should be interpreted cautiously, as wider, prospective and more homogeneous research on this topic are awaited, which could open new scenarios about environmental etiology of IBD. (www.actabiomedica.it)

Helicobacter pylori may be an initiating factor in newly diagnosed ulcerative colitis patients: A pilot study

AIM

To directly visualize Helicobacter pylori (H. pylori) by the highly sensitive and specific technique of immunohistochemical staining in colonic tissue from patients newly diagnosed with ulcerative colitis (UC).

METHODS

Colonoscopic biopsies from thirty patients with newly diagnosed UC and thirty controls were stained with Giemsa stain and immunohistochemical stain for detection of H. pylori in the colonic tissue. Results were confirmed by testing H. pylori Ag in the stool then infected patients were randomized to receive either anti H. pylori treatment or placebo.

RESULTS

Twelve/30 (40%) of the UC patients were positive for H. pylori by Giemsa, and 17/30 (56.6%) by immunohistochemistry stain. Among the control group 4/30 (13.3%) and 6/30 (20 %) were positive for H. pylori by Giemsa and immunohistochemistry staining respectively. H. pylori was significantly higher in UC than in controls (P = 0.04 and 0.007). All Giemsa positive patients and controls were positive by immunohistochemical stain. Four cases of the control group positive for H. pylori also showed microscopic features consistent with early UC.

CONCLUSION

H. pylori can be detected in colonic mucosa of patients with UC and patients with histological superficial ulcerations and mild infiltration consistent with early UC. There seems to be an association between UC and presence of H. pylori in the colonic tissue. Whether this is a causal relationship or not remains to be discovered.

The Gut Microbiota in the Pathogenesis and Therapeutics of Inflammatory Bowel Disease

In the twenty first century, the changing epidemiology of inflammatory bowel disease (IBD) globally with increasing disease incidence across many countries relates to the altered gut microbiota, due to a combinatorial effect of environmental factors, human immune responses and genetics. IBD is a gastrointestinal disease associated with a gut microbial dysbiosis, including an expansion of facultative anaerobic bacteria of the family Enterobacteriaceae. Advances in high-throughput sequencing enable us to entangle the gut microbiota in human health and IBD beyond the gut bacterial microbiota, expanding insights into the mycobiota, virobiota and helminthes. Caudovirales (viruses) and Basidiomycota, Ascomycota, and Candida albicans (fungi) are revealed to be increased in IBD. The deconvolution of the gut microbiota in IBD lays the basis for unveiling the roles of these various gut microbiota components in IBD pathogenesis and being conductive to instructing on future IBD diagnosis and therapeutics. Here we comprehensively elucidate the alterations in the gut microbiota in IBD, discuss the effect of diets in the gut microbiota in relation to IBD, and illustrate the potential of manipulation of gut microbiota for IBD therapeutics. The therapeutic strategy of antibiotics, prebiotics, probiotics and fecal microbiota transplantation will benefit the effective application of precision microbiome manipulation in IBD.

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.

Protection Against Helicobacter pylori Infection in BALB/c Mouse Model by Oral Administration of Multivalent Epitope-Based Vaccine of Cholera Toxin B Subunit-HUUC

Vaccination is an increasingly important alternative approach to control Helicobacter pylori infection, since H. pylori resistance to previously efficacious antibiotic regimens is increased, and H. pylori eradication treatment for upper gastrointestinal diseases is becoming less successful. Fortunately, an efficient oral monovalent H. pylori vaccine has been developed. However, compared with monovalent vaccines, multivalent vaccines have the potential to induce more effective and comprehensive protection against H. pylori infection. In this study, we designed and produced a multivalent epitope-based vaccine cholera toxin B subunit (CTB)-HUUC with the intramucosal adjuvant CTB and tandem copies of B-cell epitopes (HpaA132-141, UreA183-203, and UreB321-339) and T-cell epitopes (HpaA88-100, UreA27-53, UreB229-251, UreB317-329, UreB373-385, UreB438-452, UreB546-561, CagA149-164, and CagA196-217) from H. pylori adhesion A subunit (HpaA), urease A subunit (UreA), urease B subunit (UreB), and cytotoxin-associated antigen (CagA). Serum IgG, stomach, and intestine mucosal sIgA from mice after CTB-HUUC vaccination neutralized H. pylori urease activity in vitro. CTB-HUUC vaccination promoted H. pylori-specific lymphocyte responses and a mixed CD4⁺ T cell immune response as indicated by IFN-γ, interleukin-4, and interleukin-17 production in mice. Both oral prophylactic and therapeutic CTB-HUUC vaccinations reduced gastric urease activity and H. pylori infection and protected stomachs in mice. Taken together, CTB-HUUC is a promising potent and safe multivalent vaccine in controlling H. pylori infection in BALB/c mouse model.

Gut microbiota drives the attenuation of dextran sulphate sodium-induced colitis by Huangqin decoction

The gut microbiota, including probiotics and pathogenic microorganisms, is involved in ulcerative colitis (UC) by regulating pathogenic microorganisms and the production of intestinal mucosal antibodies. Huangqin decoction (HQD), a traditional Chinese formula chronicled in the Shanghan lun, has been recognized as an effective drug for UC, owing to its anti-inflammatory and anti-oxidative properties. In the present study, we investigated whether HQD ameliorates dextran sulphate sodium (DSS)-induced colitis through alteration of the gut microbiota. We found that HQD significantly inhibited colitis, alleviating the loss of body weight, disease activity index, colon shortening, tissue injury, and inflammatory cytokine changes induced by DSS treatment. Principal component analysis and principal co-ordinate analysis showed an obvious difference among the groups, with increased diversity in the DSS and DSS+HQD groups. Linear discriminant analysis effect size was used to determine differences between the groups. The relative abundance of Lactococcus was higher in the DSS+HQD group than in the DSS group, whereas Desulfovibrio and Helicobacter were decreased. Furthermore, the protective effect of HQD was attenuated only in antibiotic-treated mice. In conclusion, our results suggest that HQD could ameliorate DSS-induced inflammation through alteration of the gut microbiota.

Characteristics of Upper Gastrointestinal Tract Involvement in Korean Pediatric Crohn's Disease: A Multicenter Study

PURPOSE

Crohn's disease (CD) can involve any site of the gastrointestinal tract (GIT). However, the characteristics of upper GIT involvement in CD are unclear, especially in the Eastern pediatric population. This study aimed to estimate the prevalence of upper GIT involvement and identify the clinical features of Korean children with CD.

METHODS

This was a retrospective multicenter cohort study that included 52 pediatric patients with CD who underwent esophagogastroduodenoscopy and biopsy. The clinical symptoms and endoscopic and histologic features of the upper GIT were identified according to the presence or absence of upper gastrointestinal symptoms.

RESULTS

Among the 52 patients, upper GIT involvement was noted in 50.0% (26/52). The mean age at CD diagnosis was 14.1±2.1 years. Gastric ulcer was the most common lesion (19.2%) found on upper GIT endoscopy, followed by duodenal ulcers (15.4%). Chronic inflammation was the most common histopathologic feature (75.0%), followed by gastric erosion (17.3%). Granuloma was found in 9.6% of patients. Helicobacter pylori infection was identified in 5.8% of patients. Endoscopic and histologic findings were not significantly different, but the mean values of erythrocyte sedimentation rate (60.7±27.1 vs. 43.0±27.6 mm/h, p=0.037) and C-reactive protein (16.5±28.2 vs. 6.62±13.4 mg/dL, p=0.014) were significantly different between patients with and without upper gastrointestinal CD symptoms.

CONCLUSION

Upper GIT involvement was relatively common in pediatric patients with CD irrespective of upper gastrointestinal symptoms, and H. pylori infection was relatively uncommon. The results of this study should aid the establishment of regional guidelines for upper GIT examination.

The ethnic distribution of sessile serrated polyps in the United States is inversely associated with Helicobacter pylori prevalence

AIM

Little is known about the epidemiology of sessile serrated polyps (SSP). Our study aimed to investigate the influence of Helicobacter pylori gastritis and patient demographic characteristics (age, gender, ethnicity) on the prevalence of SSP using a large national database of patients undergoing bi-directional endoscopy.

METHOD

De-identified patient data were extracted from the Miraca Life Sciences electronic database of histopathological reports. Using multivariate logistic regression analysis, the influence of H. pylori gastritis and demographic characteristics on the occurrence of SSP were expressed as odds ratios (OR) with their 95% confidence intervals (CI).

RESULTS

The total study population comprised 228 506 subjects, of whom 28 890 carried a diagnosis of H. pylori gastritis and 11 285 SSP. Age (OR 4.35, 95% CI: 3.82-4.96), female gender (0.92, 0.88-0.95) and H. pylori gastritis (0.94, 0.88-0.99) exerted the strongest influence on the occurrence of SSP. In comparison with the population comprising Caucasians and African Americans, SSP were less common among subjects of Hispanic (0.67, 0.62-0.73), East Asian (0.59, 0.50-0.69), Indian (0.43, 0.27-0.64) or Middle Eastern descent (0.61, 0.41-0.87). All these ethnic subgroups were also characterized by a higher prevalence of H. pylori than the comparison group. A low prevalence of H. pylori was significantly associated with a high prevalence of SSP (R²  = 0.82, P < 0.001).

CONCLUSION

The prevalence of SSP within the United States is characterized by a marked ethnic variation. The inverse correlation between the prevalence of H. pylori and SSP suggests that gastric infection with H. pylori may be partly responsible for the observed ethnic distribution of SSP.