The Gastric and Intestinal Microbiome: Role of Proton Pump Inhibitors

A Novel Characteristic Gastric Mucus Named "Web-like Mucus" Potentially Induced by Vonoprazan

Background: In the absence of Helicobacter pylori (HP) infection, a characteristic gastric mucus adhesion may appear during the use of vonoprazan. We named this novel characteristic mucus "web-like mucus" (WLM). This study aimed to determine the incidence and risk factors for WLM. Methods: Between January 2017 and January 2022, 5665 patients were enrolled in this study. The patients were divided into a proton-pump inhibitor (PPI)-prescribed group (n = 2000), a vonoprazan-prescribed group (n = 268), and a no-PPI/vonoprazan-prescribed (n = 3397) group, and the presence of WLM was examined. After excluding four patients with autoimmune gastritis, the remaining 264 patients in the vonoprazan group were divided into WLM and non-WLM groups, and their clinical features were analyzed. Results: A total of 55 (21%) patients had WLM, all in the vonoprazan-prescribed group. There were no significant differences in factors such as, sex, age, chronic kidney disease, diabetes mellitus, HP eradication history, smoking, or alcohol consumption between the WLM and non-WLM groups. The median duration from the start of vonoprazan administration to the endoscopic detection of WLM was 2 (1-24) months. Conclusions: WLM appears to be a characteristic feature in patients treated with vonoprazan.

Maintenance proton pump inhibitor use and risk of colorectal cancer: a Swedish retrospective cohort study

OBJECTIVES

We aimed to evaluate the risk of colorectal adenocarcinoma (CRA) associated with long-term use of proton pump inhibitors (PPIs) in a large nationwide cohort.

DESIGN

Retrospective cohort study.

SETTING

This research was conducted at the national level, encompassing the entire population of Sweden.

PARTICIPANTS

This study utilised Swedish national registries to identify all adults who had ≥180 days of cumulative PPI use between July 2005 and December 2012, excluding participants who were followed up for less than 1 year. A total of 754 118 maintenance PPI users were included, with a maximum follow-up of 7.5 years.

INTERVENTIONS

Maintenance PPI use (cumulative≥180 days), with a comparator of maintenance histamine-2 receptor antagonist (H2RA) use.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measure was the risk of CRA, presented as standardised incidence ratios (SIRs) with 95% confidence intervals (CIs). Subgroup analyses were performed to explore the impact of indications, tumour locations, tumour stages and the duration of follow-up. A multivariable Poisson regression model was fitted to estimate the incidence rate ratios (IRRs) and 95% CIs of PPI versus H2RA use.

RESULTS

Maintenance PPI users exhibited a slightly elevated risk of CRA compared to the general population (SIR 1.10, 95% CI=1.06 to 1.13) for both men and women. Individuals aged 18-39 (SIR 2.79, 95% CI=1.62 to 4.47) and 40-49 (SIR 2.02, 95% CI=1.65 to 2.45) had significantly higher risks than the general population. Right-sided CRA showed a higher risk compared to the general population (SIR 1.26, 95% CI=1.20 to 1.32). There was no significant difference in the risk of CRA between maintenance PPI users and maintenance H2RA users (IRR 1.05, 95% CI=0.87 to 1.27, p<0.05).

CONCLUSIONS

Maintenance PPI use may be associated with an increased risk of CRA, but a prolonged observation time is needed.

Microbial Symphony: Exploring the Role of the Gut in Osteoarthritis-Related Pain. A Narrative Review

One of the most common musculoskeletal disorders, osteoarthritis (OA), causes worldwide disability, morbidity, and poor quality of life by degenerating articular cartilage, modifying subchondral bone, and inflaming synovial membranes. OA pathogenesis pathways must be understood to generate new preventative and disease-modifying therapies. In recent years, it has been acknowledged that gut microbiota (GM) can significantly contribute to the development of OA. Dysbiosis of GM can disrupt the "symphony" between the host and the GM, leading to a host immunological response that activates the "gut-joint" axis, ultimately worsening OA. This narrative review summarizes research supporting the "gut-joint axis" hypothesis, focusing on the interactions between GM and the immune system in its two main components, innate and adaptive immunity. Furthermore, the pathophysiological sequence of events that link GM imbalance to OA and OA-related pain is broken down and further investigated. We also suggest that diet and prebiotics, probiotics, nutraceuticals, exercise, and fecal microbiota transplantation could improve OA management and represent a new potential therapeutic tool in the light of the scarce panorama of disease-modifying osteoarthritis drugs (DMOADs). Future research is needed to elucidate these complex interactions, prioritizing how a particular change in GM, i.e., a rise or a drop of a specific bacterial strain, correlates with a certain OA subset to pinpoint the associated signaling pathway that leads to OA.

Potential effects of the most prescribed drugs on the microbiota-gut-brain-axis: A review

The link between drug-induced dysbiosis and its influence on brain diseases through gut-residing bacteria and their metabolites, named the microbiota-gut-brain axis (MGBA), remains largely unexplored. This review investigates the effects of commonly prescribed drugs (metformin, statins, proton-pump-inhibitors, NSAIDs, and anti-depressants) on the gut microbiota, comparing the findings with altered bacterial populations in major brain diseases (depression, multiple sclerosis, Parkinson's and Alzheimer's). The report aims to explore whether drugs can influence the development and progression of brain diseases via the MGBA. Central findings indicate that all explored drugs induce dysbiosis. These dysbiosis patterns were associated with brain disorders. The influence on brain diseases varied across different bacterial taxa, possibly mediated by direct effects or through bacterial metabolites. Each drug induced both positive and negative changes in the abundance of bacteria, indicating a counterbalancing effect. Moreover, the above-mentioned drugs exhibited similar effects, suggesting that they may counteract or enhance each other's effects on brain diseases when taken together by comorbid patients. In conclusion, the interplay of bacterial species and their abundances may have a greater impact on brain diseases than individual drugs or bacterial strains. Future research is needed to better understand drug-induced dysbiosis and the implications for brain disease pathogenesis, with the potential to develop more effective therapeutic options for patients with brain-related diseases.

Proton pump Inhibitors and Risk of Enteric Infection in Inflammatory Bowel Disease: A Self-controlled Case Series

BACKGROUND

We tested whether proton pump inhibitors (PPIs) are associated with enteric infections among those with inflammatory bowel disease (IBD), after adequately accounting for baseline differences between PPI users and nonusers.

METHODS

This was a self-controlled case series, with each patient serving as their own control. Ambulatory patients with IBD were included if they were tested for enteric infection by multiplex polymerase chain reaction testing panel (GIPCR) and/or Clostridoides difficile toxin PCR from 2015 to 2019 and received PPIs for some but not all of this period. Rates of enteric infections were compared between the PPI-exposed period vs pre- and post-PPI periods identical in duration to the exposed period. Conditional Poisson regression was used to adjust for time-varying factors.

RESULTS

Two hundred twenty-one IBD patients were included (49% ulcerative colitis, 46% Crohn's disease, and 5% indeterminate colitis). The median PPI duration was 7 months (interquartile range 4 to 11 months). A total of 25 (11%) patients had a positive GIPCR or C. difficile test in the PPI period, 9 (4%) in the pre-PPI period, and 8 (4%) in the post-PPI period. Observed incidence rates for enteric infections were 2.5, 7.4, and 2.2 per 100 person years for the pre-PPI, PPI, and post-PPI periods, respectively (adjusted incidence rate ratios, 2.8; 95% confidence interval [CI] 1.3-6.0) for PPI vs pre-PPI and 2.9 (95% CI, 1.3-6.4) for PPI vs post-PPI). The adjusted absolute excess risk associated with PPIs was 4.9 infections per 100 person years.

CONCLUSIONS

Proton pump inhibitors were associated with a 3-fold increased risk for enteric infection among those with IBD but had a modest absolute risk.

Advancing our understanding of the influence of drug induced changes in the gut microbiome on bone health

The gut microbiome has been implicated in a multitude of human diseases, with emerging evidence linking its microbial diversity to osteoporosis. This review article will explore the molecular mechanisms underlying perturbations in the gut microbiome and their influence on osteoporosis incidence in individuals with chronic diseases. The relationship between gut microbiome diversity and bone density is primarily mediated by microbiome-derived metabolites and signaling molecules. Perturbations in the gut microbiome, induced by chronic diseases can alter bacterial diversity and metabolic profiles, leading to changes in gut permeability and systemic release of metabolites. This cascade of events impacts bone mineralization and consequently bone mineral density through immune cell activation. In addition, we will discuss how orally administered medications, including antimicrobial and non-antimicrobial drugs, can exacerbate or, in some cases, treat osteoporosis. Specifically, we will review the mechanisms by which non-antimicrobial drugs disrupt the gut microbiome's diversity, physiology, and signaling, and how these events influence bone density and osteoporosis incidence. This review aims to provide a comprehensive understanding of the complex interplay between orally administered drugs, the gut microbiome, and osteoporosis, offering new insights into potential therapeutic strategies for preserving bone health.

Green carbon dots derived from Atractylodes macrocephala: A potential nanodrug for treating alcoholic gastric ulcer

Alcoholic gastric ulcer is a common acute gastric injury disease. The drugs currently used in clinical practice not only cannot fundamentally treat gastric injury, but also have serious side effects. There is an urgent demand for the discovery of a mild drug to treat alcoholic gastric ulcers. Herein, the green carbon dots derived from charred Atractylodes macrocephala (CAM-CDs) were acquired and have been proven to be safe and effective in alleviating alcoholic gastric ulcers at an inhibition rate up to 60%. CAM-CDs can markedly attenuate the gastric mucosa damage such as mucosal defect, bleeding and inflammatory cell infiltration by histopathological examination. Serum and tissue inflammatory cytokine measurements, as well as immunohistochemistry results, indicate that its mechanism of gastric mucosal protection may involve the reduction of IL-1β and TNF-α by regulating inflammatory signaling pathway of the NF-κB/NLRP3 axis, as well as elevation of IL-10 levels. CAM-CDs also can reduce oxidative stress markers (MDA), increase PGE2 and mucin secretion (MUC5AC), and it simultaneously exerts slight inhibition of hydrogen potassium ATPase and pepsin activity to protect gastric mucosa, as well as increases the microbial diversity and regulates species composition of gut microbiota in rats with gastric ulcer. Our work provides a new perspective on utilizing carbon-based nanomaterials in the development of new mild drugs.

Meta-analysis of the effects of proton pump inhibitors on the human gut microbiota

Mounting evidence has linked changes in human gut microbiota to proton pump inhibitor (PPI) use. Accordingly, multiple studies have analyzed the gut microbiomes of PPI users, but PPI-microbe interactions are still understudied. Here, we performed a meta-analysis of four studies with available 16S rRNA gene amplicon sequencing data to uncover the potential changes in human gut microbes among PPI users. Despite some differences, we found common features of the PPI-specific microbiota, including a decrease in the Shannon diversity index and the depletion of bacteria from the Ruminococcaceae and Lachnospiraceae families, which are crucial short-chain fatty acid-producers. Through training based on multiple studies, using a random forest classification model, we further verified the representativeness of the six screened gut microbial genera and 20 functional genes as PPI-related biomarkers, with AUC values of 0.748 and 0.879, respectively. Functional analysis of the PPI-associated 16S rRNA microbiome revealed enriched carbohydrate- and energy-associated genes, mostly encoding fructose-1,6-bisphosphatase and pyruvate dehydrogenase, among others. In this study, we have demonstrated alterations in bacterial abundance and functional metabolic potential related to PPI use, as a basis for future studies on PPI-induced adverse effects.

Gastric juice microbiota in pediatric chronic gastritis that clinically tested positive and negative for Helicobacter pylori

Purpose

Helicobacter pylori (HP) infection is an identified risk factor for pediatric chronic gastritis (PCG), but its impact on gastric juice microbiota (GJM) remains to be further elucidated in PCG. This study aimed to analyze and compare the microbial communities and microbial interactive networks of GJM in PCG that clinically tested positive and negative for HP (HP+ and HP-, respectively).

Methods

A total of 45 PCG patients aged from 6 to 16 years were recruited, including 20 HP+ and 25 HP- patients tested by culture and rapid urease test. Gastric juice samples were collected from these PCG patients and subjected to high-throughput amplicon sequencing and subsequent analysis of 16S rRNA genes.

Results

While no significant change in alpha diversity, significant differences in beta diversity were observed between HP+ and HP- PCG. At the genus level, Streptococcus, Helicobacter, and Granulicatella were significantly enriched in HP+ PCG, whereas Campylobacter and Absconditabacteriales (SR1) were significantly enriched in HP- PCG. Network analysis showed that Streptococcus was the only genus positively correlated with Helicobacter (r = 0.497) in the GJM network of overall PCG. Moreover, compared to HP- PCG, HP+ PCG showed a reduction in microbial network connectivity in GJM. Netshift analysis identified driver microbes including Streptococcus and other four genera, which substantially contributed to the GJM network transition from HP- PCG to HP+ PCG. Furthermore, Predicted GJM function analysis indicated up-regulated pathways related to the metabolism of nucleotides, carbohydrates, and L-Lysine, the urea cycle, as well as endotoxin peptidoglycan biosynthesis and maturation in HP+ PCG.

Conclusion

GJM in HP+ PCG exhibited dramatically altered beta diversity, taxonomic structure, and function, with reduced microbial network connectivity, which could be involved in the disease etiology.

Proton Pump Inhibitors and Risk of Chronic Kidney Disease: Evidence from Observational Studies

Previous epidemiological studies have raised the concern that the use of proton pump inhibitors (PPIs) is associated with an increased risk of kidney diseases. To date, no comprehensive meta-analysis has been conducted to assess the association between PPIs and the risk of chronic kidney disease (CKD). Therefore, we conducted a systematic review and meta-analysis to address the association between PPIs and CKD. The primary search was conducted in the most popular databases, such as PubMed, Scopus, and Web of Science. All observational studies evaluated the risk of CKD among PPI users, and non-users were considered for inclusion. Two reviewers conducted data extraction and assessed the risk of bias. Random-effect models were used to calculate pooled effect sizes. A total of 6,829,905 participants from 10 observational studies were included. Compared with non-PPI use, PPI use was significantly associated with an increased risk of CKD (RR 1.72, 95% CI: 1.02–2.87, p = 0.03). This updated meta-analysis showed that PPI was significantly associated with an increased risk of CKD. Association was observed in the same among moderate-quality studies. Until further randomized control trials (RCTs) and biological studies confirm these results, PPI therapy should not stop patients with gastroesophageal reflux disease (GERD). However, caution should be used when prescribing to patients with high-risk kidney disease.

Effect of Antacid Use on Immune Checkpoint Inhibitors in Advanced Solid Cancer Patients: A Systematic Review and Meta-analysis

The influence of antacids use on immune checkpoint inhibitor (ICI) efficacy remains unclear. A systematic review and meta-analysis was performed to evaluate the effect of proton pump inhibitors (PPIs) and histamine-2-receptor antagonists (H2RAs) on ICI efficacy in advanced solid cancer patients. A systematic literature search in PubMed, EMBASE, and Web of Science was performed to retrieve studies investigating the effect of antacid use on ICI efficacy. Overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and immune-related adverse events were measured using hazard ratios (HRs) or odds ratios (ORs). Thirty studies enrolling 16,147 advanced cancer patients receiving ICI treatment were included. The pooled analysis indicated that PPI use was associated with shorter OS (HR=1.40, 95% CI, 1.25-1.57) and PFS (HR=1.34, 95% CI, 1.19-1.52) in advanced cancer patients treated with ICIs. PPI use did not show effect on ORR or immune-related adverse event of advanced cancer patients receiving ICI treatment. OS, PFS, and ORR did not differ between H2RA users and non-H2RA users. In subgroup analyses, PPI use was associated with shorter OS and PFS in NSCLC and urothelial carcinoma patients and in patients treated with anti-programmed cell death 1 or anti-programmed cell death ligand 1 monotherapy. In addition, ICI efficacy was different in the antacid exposure time frame subgroups. In conclusion, PPI use has a negative effect on OS and PFS among advanced cancer patients receiving ICI treatment. PPIs should be cautiously administered among advanced cancer patients treated with ICI. The safety of H2RAs and the influence of H2RAs on ICI efficacy need further investigation.

Proton Pump Inhibitor Pantoprazole Modulates Intestinal Microbiota and Induces TLR4 Signaling and Fibrosis in Mouse Liver

Proton pump inhibitors (PPIs) are one of the most prescribed drugs around the world. PPIs induce microbiota modulation such as obesity both in humans and in animal models. However, since PPIs can induce microbiota modulation despite the absence of a high-fat diet or weight gain, it is an interesting model to correlate microbiota modulation with the establishment of non-alcoholic fatty liver disease (NAFLD). We investigated the effect of pantoprazole treatment on TLR4 signaling and liver histology in C57BL/6J mice for 60 days, trying to correlate microbiota modulation with some aspects of liver injury. We performed glucose (GTT) and insulin (ITT) tolerance tests, serum lipopolysaccharide (LPS) dosage, liver histology, liver and intestine extraction for Western blot and qPCR. Fecal microbiota were investigated via metagenomics. Chronic treatment with pantoprazole induced microbiota modulation and impaired ileum barrier integrity, without an association with insulin resistance. Furthermore, increased circulating LPS and increased Toll-like receptor 4 (TLR4) and TGFβ downstream signaling may have an important role in the development of the observed liver microvesicular steatosis and fibrosis. Finally, this model of PPI-induced changes in microbiota might be useful to investigate liver microvesicular steatosis and fibrosis.

The microbiota in eosinophilic esophagitis: A systematic review

Eosinophilic esophagitis (EoE) is an atopic disease of the esophagus that has shown a significant increase in incidence and prevalence in the last 20 years. The etiology of EoE is unclear, and few studies explore the esophageal microbiota in EoE. The local microbiome has been implicated in the pathogenesis of several allergic and inflammatory diseases, such as asthma and eczema. In this study, we performed a systematic review to evaluate differences in the microbiota profile of patients with EoE compared with controls. MEDLINE, Embase, Cochrane Library, Scopus, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) databases were searched to identify studies investigating the microbiota composition in EoE. Three reviewers screened the articles for eligibility and quality. Seven articles underwent full-text review, and a narrative synthesis was undertaken. The microbiota of the mouth and esophagus are correlated. Patients with active EoE present increased esophageal microbial load and increased abundance in particular species, such as Haemophilus and Aggregatibacter. On the other hand, EoE patients present a decrease in Firmicutes. High microbial load and abundance of Haemophilus are observed in EoE patients, but little evidence exists to demonstrate their influence on inflammation and disease. Understanding microbial signatures in EoE might contribute to the development of novel therapeutic strategies.

Electroacupuncture ameliorates peptic ulcer disease in association with gastroduodenal microbiota modulation in mice

Peptic ulcer disease (PUD) is a common disease and frequently encountered in the clinic. Accumulating evidence suggests that PUD is associated with the gastrointestinal microbiota. Electroacupuncture (EA) is an improved version of acupuncture, which can improve the clinical effect by increasing the stimulation and delivering appropriate electrical pulses to needles. This method has been widely used in the treatment of peptic ulcer disease. However, its effect on gastrointestinal microbiota remains unclear. Therefore, in the present study, the ameliorative effect of EA was evaluated on the gastroduodenal mucosa, and the regulatory effect of the gastroduodenal microbiota was assessed in PUD mice. A total of 48 male Kun Ming mice were randomly divided into the following groups: normal control group (NC), PUD model group (PUD), Shousanli group (LI10), and Zusanli group (ST36) (n=12). The mice in groups LI10 and ST36 were treated with EA at LI10 and ST36, respectively. This intervention was continued for 7 days. Subsequently, we evaluated the morphological changes in the gastric and duodenal mucosa, and specific indices were measured, including the contents of serum dopamine (DA), the trefoil factor (TFF), and the vasoactive intestinal peptide (VIP). In addition, the gastric and duodenal microbiota were assessed via 16S ribosomal DNA sequencing. The results indicated that EA at LI10 or ST36 significantly reduced the injury of the gastroduodenal mucosa in PUD mice. The gastric microbial community structure of the groups LI10 and ST36 was similar to that of the NC group following comparison with the microbial community structure of the PUD model group. Moreover, the abundance of Firmicutes in the stomach was decreased, whereas that of Bacteroidetes was increased, and the abundance of Firmicutes in the duodenum was decreased. Furthermore, the microbial diversity and richness of the gastric microbiota in group LI10 were also significantly increased, and the serum dopamine and trefoil factor levels in group ST36 were significantly increased. Therefore, it is suggested that EA ameliorating PUD is in association with improving the levels of DA and TFF and regulating the relative abundances of Firmicutes and Bacteroidetes in the gastric microbiota.

Management of Helicobacter pylori infection: the Maastricht VI/Florence consensus report

Helicobacter pyloriInfection is formally recognised as an infectious disease, an entity that is now included in the International Classification of Diseases 11th Revision. This in principle leads to the recommendation that all infected patients should receive treatment. In the context of the wide clinical spectrum associated with Helicobacter pylori gastritis, specific issues persist and require regular updates for optimised management.The identification of distinct clinical scenarios, proper testing and adoption of effective strategies for prevention of gastric cancer and other complications are addressed. H. pylori treatment is challenged by the continuously rising antibiotic resistance and demands for susceptibility testing with consideration of novel molecular technologies and careful selection of first line and rescue therapies. The role of H. pylori and antibiotic therapies and their impact on the gut microbiota are also considered.Progress made in the management of H. pylori infection is covered in the present sixth edition of the Maastricht/Florence 2021 Consensus Report, key aspects related to the clinical role of H. pylori infection were re-evaluated and updated. Forty-one experts from 29 countries representing a global community, examined the new data related to H. pylori infection in five working groups: (1) indications/associations, (2) diagnosis, (3) treatment, (4) prevention/gastric cancer and (5) H. pylori and the gut microbiota. The results of the individual working groups were presented for a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in various clinical fields.

A Prescribing Cascade of Proton Pump Inhibitors Following Anticholinergic Medications in Older Adults With Dementia

Introduction: Prescribing cascade refers to use of a medication to treat a drug-related adverse event. Prescribing cascades increase medication use, cost, and risk of adverse events.

Objective: Our objective was to use administrative health data to identify whether use of medications from the anticholinergic cognitive burden scale was associated with proton pump inhibitor (PPI) prescribing consistent with a prescribing cascade in older adults with dementia.

Method: The cohort was comprised of Nova Scotia Seniors’ Pharmacare beneficiaries identified to have dementia and medication dispensation data recorded between 1 April 2010, or cohort entry and 31 March 2015. Anticholinergic medications from the anticholinergic cognitive burden scale (ACB) were abstracted. A look back period of 365 days identified if a PPI had been dispensed preceding anticholinergic dispensation. PPI initiation within 30, 60, 90, or 180 days of the anticholinergic medication was assessed. Demographic description of those dispensed anticholinergic medications or PPIs were reported. Risk factors for the prescribing cascade were investigated with logistic regression and Cox proportional hazards modelling including a sex-stratified analysis.

Results: We identified 28,952 Nova Scotia Seniors’ Pharmacare beneficiaries with dementia and prescription dispensation data. Anticholinergic medications were frequently dispensed with 63.4% of the cohort dispensed at least one prescription for an anticholinergic medication. The prescribing cascade defined as up to 180-days between anticholinergic medication inititation and PPI dispensation, occurred in 1,845 Nova Scotia Seniors’ Pharmacare beneficiaries with dementia (incidence 6.4%). Multivariate regression showed those experiencing the prescribing cascade after initiating any anticholinergic were younger (OR 0.98, 95%CI [0.97–0.98]), less likely to live in an urban location (OR 0.82, 95%CI [0.74–0.91]), or to be men (OR 0.74, 95%CI [0.67–0.82]). Cox regression demonstrated an increased risk of starting a PPI within 180 days when initiating any medication from the ACB (HR 1.38, 95%CI [1.29–1.58]).

Discussion: Regression modelling suggested that anticholinergic medications increased the risk of PPI dispensation consistent with a prescribing cascade in the cohort. The identification of the prescribing cascade in this population of older Nova Scotia Seniors’ Pharmacare Program beneficiaries with dementia using administrative health data highlights how routinely collected health data can be used to identify prescribing cascades.

Influence of concomitant gastric acid suppressants use on the survival of patients with non-small cell lung cancer treated with programmed death-1/ligand-1 inhibitors: A meta-analysis

INTRODUCTION

Influence of concomitant use of gastric acid suppressants (GAS) on survival of non-small cell lung cancer (NSCLC) patients receiving programmed death-1/ligand-1 (PD-1/PD-L1) inhibitors has rarely been comprehensively evaluated. A meta-analysis was performed to systematically evaluate the effect of concomitant GAS in NSCLC patients receiving PD-1/PD-L1inhibitors.

METHODS

Relevant observational studies were identified by search of Medline, Embase, and Web of Science databases from inception to May 26, 2022. A random-effect model which incorporates the possible between-study heterogeneity was used to combine the results.

RESULTS

Ten retrospective and one prospective cohort studies including 5892 patients were patients were included. Influence of concomitant proton pump inhibitors (PPIs) was evaluated in ten studies, and influence of GAS, including PPIs or histamine type-2 receptor antagonists were evaluated in one study. Pooled results showed that concomitant use of GAS was associated with worse progression-free survival (PFS, adjusted hazard ratio [HR]: 1.32, 95% confidence interval [CI]: 1.20 to 1.45, P < 0.001; I² = 0%) and overall survival (OS, adjusted HR: 1.36, 95% CI: 1.26 to 1.48, P < 0.001; I² = 0%) in NSCLC patients taking PD-1/PD-L1inhibitors. Subgroup analyses indicated that the association between concomitant use of GAS and poor survival in NSCLC patients taking PD-L1inhibitors was consistent in univariate and multivariate studies (P values for subgroup difference both > 0.05 for PFS and OS).

CONCLUSIONS

The meta-analysis by summarizing the up-to-date literatures showed that use of GAS, primarily PPIs, may be associated with poor survival outcomes in patients with NSCLC receiving PD-1/PD-L1inhibitors.

Kitchen Diet vs. Industrial Diets-Impact on Intestinal Barrier Parameters among Stroke Patients

Background and aims: Strokes are the second highest cause of death in the world and the most common cause of permanent disability in adults. Intestinal barrier permeability thus contributes to diminished homeostasis within the body, which further affects the healing process and convalescence. Each stroke patient should be administered with ingredients that support the intestinal barrier (e.g., protein and fiber). The aim of this study was to compare the effect of various types of diet (enteral with or without fiber vs. a mixed kitchen diet) on the metabolic activity of intestinal microbiota, namely short chain fatty acids, and gut barrier integrity parameters (zonulin and calprotectin. Methods: Patients (n = 59), after suffering an ischemic stroke, were randomly allocated to three groups receiving: the kitchen diet (n = 32; 1.2 g fiber in 100 mL); Nutrison Energy^® (n = 14; 0.02 g fiber in 100 mL); and Nutrison Diason Energy HP^® (n = 13; 1.8 g fiber in 100 mL). The patients underwent anthropometric measurements and blood samples (for prealbumin measurements), and stool samples (for zonulin and calprotectin determinations) were taken twice, on admission and a week later. Results: Industrial diets enriched with fiber maintained nutritional status and had a beneficial effect on intestinal barrier permeability parameters. Patients fed with kitchen diets demonstrated a decreased number of lymphocytes, hemoglobin, erythrocytes, and increased serum concentration of C-reactive protein, but improved gut barrier markers. Proton pump inhibitors were shown to increase the inflammatory process in gut. Conclusions: Stroke patients should be administered with industrial diets enriched with fiber to improve gut barrier integrity and nutritional parameters.

A Gut Feeling in Amyotrophic Lateral Sclerosis: Microbiome of Mice and Men

Amyotrophic lateral sclerosis (ALS) is a severely debilitating disease characterized by progressive degeneration of motor neurons. ALS etiology and pathophysiology are not well understood. It could be the consequences of complex interactions among host factors, microbiome, and the environmental factors. Recent data suggest the novel roles of intestinal dysfunction and microbiota in ALS etiology and progression. Although microbiome may indeed play a critical role in ALS pathogenesis, studies implicating innate immunity and intestinal changes in early disease pathology are limited. The gastrointestinal symptoms in the ALS patients before their diagnosis are largely ignored in the current medical practice. This review aims to explore existing evidence of gastrointestinal symptoms and progress of microbiome in ALS pathogenesis from human and animal studies. We discuss dietary, metabolites, and possible therapeutic approaches by targeting intestinal function and microbiome. Finally, we evaluate existing evidence and identify gaps in the knowledge for future directions in ALS. It is essential to understanding the microbiome and intestinal pathogenesis that determine when, where, and whether microbiome and metabolites critical to ALS progression. These studies will help us to develop more accurate diagnosis and better treatment not only for this challenging disease, but also for other neurodegenerative diseases.

Murine Model for Measuring Effects of Humanized-Dosing of Antibiotics on the Gut Microbiome

There is a current need for enhancing our insight in the effects of antimicrobial treatment on the composition of human microbiota. Also, the spontaneous restoration of the microbiota after antimicrobial treatment requires better understanding. This is best addressed in well-defined animal models. We here present a model in which immune-competent or neutropenic mice were administered piperacillin-tazobactam (TZP) according to human treatment schedules. Before, during and after the TZP treatment, fecal specimens were longitudinally collected at established intervals over several weeks. Gut microbial taxonomic distribution and abundance were assessed through culture and molecular means during all periods. Non-targeted metabolomics analyses of stool samples using Quadrupole Time of Flight mass spectrometry (QTOF MS) were also applied to determine if a metabolic fingerprint correlated with antibiotic use, immune status, and microbial abundance. TZP treatment led to a 5–10-fold decrease in bacterial fecal viability counts which were not fully restored during post-antibiotic follow up. Two distinct, relatively uniform and reproducible restoration scenarios of microbiota changes were seen in post TZP-treatment mice. Post-antibiotic flora could consist of predominantly Firmicutes or, alternatively, a more diverse mix of taxa. In general, the pre-treatment microbial communities were not fully restored within the screening periods applied. A new species, closely related to Eubacterium siraeum, Mageeibacillus indolicus, and Saccharofermentans acetigenes, became predominant post-treatment in a significant proportion of mice, identified by 16S rRNA gene sequencing. Principal component analysis of QTOF MS of mouse feces successfully distinguished treated from non-treated mice as well as immunocompetent from neutropenic mice. We observe dynamic but distinct and reproducible responses in the mouse gut microbiota during and after TZP treatment and propose the current murine model as a useful tool for defining the more general post-antibiotic effects in the gastro-intestinal ecosystem where humanized antibiotic dosing may ultimately facilitate extrapolation to humans.

Enteric nervous system modulation of luminal pH modifies the microbial environment to promote intestinal health

The enteric nervous system (ENS) controls many aspects of intestinal homeostasis, including parameters that shape the habitat of microbial residents. Previously we showed that zebrafish lacking an ENS, due to deficiency of the sox10 gene, develop intestinal inflammation and bacterial dysbiosis, with an expansion of proinflammatory Vibrio strains. To understand the primary defects resulting in dysbiosis in sox10 mutants, we investigated how the ENS shapes the intestinal environment in the absence of microbiota and associated inflammatory responses. We found that intestinal transit, intestinal permeability, and luminal pH regulation are all aberrant in sox10 mutants, independent of microbially induced inflammation. Treatment with the proton pump inhibitor, omeprazole, corrected the more acidic luminal pH of sox10 mutants to wild type levels. Omeprazole treatment also prevented overabundance of Vibrio and ameliorated inflammation in sox10 mutant intestines. Treatment with the carbonic anhydrase inhibitor, acetazolamide, caused wild type luminal pH to become more acidic, and increased both Vibrio abundance and intestinal inflammation. We conclude that a primary function of the ENS is to regulate luminal pH, which plays a critical role in shaping the resident microbial community and regulating intestinal inflammation.

Association of proton-pump inhibitor use with adverse health outcomes: A systematic umbrella review of meta-analyses of cohort studies and randomised controlled trials

AIMS

The aim was to perform an umbrella review to summarise the existing evidence on proton-pump inhibitor (PPI) use and adverse outcomes and to grade the certainty of evidence.

METHODS

Electronic databases were searched up to July 2021 for meta-analyses of cohort studies and/or randomised controlled trials (RCTs). Summary effect sizes from a random-effects model, between-study heterogeneity, 95% prediction interval, small-study effect, excess significance and credibility ceilings were devised to classify the credibility of evidence from meta-analyses of cohort studies, whereas the GRADE approach was used for meta-analyses of RCTs.

RESULTS

In meta-analyses of cohort studies, 52 of the 91 examined associations were statistically significant (P ≤ .05). Convincing evidence emerged from main analysis for the association between PPI use and risk of all-site fracture and chronic kidney disease in the elderly population. However, none of these associations remained supported by convincing evidence after sensitivity analyses. The use of PPI is also associated with an increased risk of mortality due to COVID-19 infection and other related adverse outcomes, but the quality of evidence was weak. In meta-analyses of RCTs, 38 of the 63 examined associations were statistically significant. However, no associations were supported by high or moderate-quality evidence.

CONCLUSION

This study's findings imply that most putative adverse outcomes associated with PPI use may not be supported by high-quality evidence and are likely to have been affected by underlying confounding factors. Future research is needed to confirm the causal association between PPI use and risk of fracture and chronic kidney disease.

FTACMT study protocol: a multicentre, double-blind, randomised, placebo-controlled trial of faecal microbiota transplantation for autism spectrum disorder

INTRODUCTION

Autism spectrum disorder (ASD) is a complicated diffuse developmental disorder that commonly involves gastrointestinal distress and dysbacteriosis. Emerging lines of evidence have shown faecal microbiota transplantation (FMT) to be a potential therapeutic strategy for improving the clinical outcomes of patients with ASD by re-establishing their intestinal microflora. We are undertaking the first-ever multicentre, double-blind, randomised controlled trial of FMT for the treatment of children with both ASD and gastrointestinal symptoms and will assess the feasibility and efficacy outcomes of this strategy.

METHODS

In total, 318 children with both ASD and gastrointestinal symptoms will be enrolled (from 15 hospitals in China) to receive either FMT intervention (n=212) or a placebo (control, n=106). Children aged 3-6 years will take two capsules two times a day, and those older than 6 years will take three capsules two times a day. Each patient will receive four treatment courses, with each 12-day course being repeated every month. Outcomes will be evaluated at baseline, throughout the period of intervention, and at subsequent follow-ups for 2 months. The primary trial objective is to investigate the remodelling effect of FMT on the intestinal microflora in patients with ASD. The secondary objective focuses on the clinical efficacy and safety of FMT, including its improvement of the clinical response and metabonomics.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the hospital Ethics Committee of each Faecal Transfer for ASD China Multicenter Trial Working Group. The ongoing FMT clinical trial is intended to support the approval of the new technology and its administration. The results of this trial will provide high-quality evidence to inform the future clinical application of this new therapy.

TRIAL REGISTRATION NUMBER

ChiCTR2100043906; Pre-results.

Duodenal Dysbiosis and Relation to the Efficacy of Proton Pump Inhibitors in Functional Dyspepsia

Proton pump inhibitors (PPI) may improve symptoms in functional dyspepsia (FD) through duodenal eosinophil-reducing effects. However, the contribution of the microbiome to FD symptoms and its interaction with PPI remains elusive. Aseptic duodenal brushings and biopsies were performed before and after PPI intake (4 weeks Pantoprazole 40 mg daily, FD-starters and controls) or withdrawal (2 months, FD-stoppers) for 16S-rRNA sequencing. Between- and within-group changes in genera or diversity and associations with symptoms or duodenal factors were analyzed. In total, 30 controls, 28 FD-starters and 19 FD-stoppers were followed. Mucus-associated Porphyromonas was lower in FD-starters vs. controls and correlated with symptoms in FD and duodenal eosinophils in both groups, while Streptococcus correlated with eosinophils in controls. Although clinical and eosinophil-reducing effects of PPI therapy were unrelated to microbiota changes in FD-starters, increased Streptococcus was associated with duodenal PPI effects in controls and remained higher despite withdrawal of long-term PPI therapy in FD-stoppers. Thus, duodenal microbiome analysis demonstrated differential mucus-associated genera, with a potential role of Porphyromonas in FD pathophysiology. While beneficial effects of short-term PPI therapy were not associated with microbial changes in FD-starters, increased Streptococcus and its association with PPIeffects in controls suggest a role for duodenal dysbiosis after long-term PPI therapy.

Survival outcomes of patients with nonsmall cell lung cancer concomitantly receiving proton pump inhibitors and immune checkpoint inhibitors

Recent evidence suggests that gut microbiota dysbiosis adversely affects the efficacy of immune checkpoint inhibitors (ICIs). Our objective was to investigate the association between concomitant use of proton pump inhibitors (PPIs) and ICIs, and poor prognosis in patients with nonsmall cell lung cancer (NSCLC). We conducted a cohort study using a completely enumerated lung cancer cohort from a nationwide healthcare database in South Korea. We identified 2963 patients treated with ICIs as second-line or later therapy for stage ≥IIIB NSCLC. PPI use was ascertained within 30-days before and on the date of ICI initiation, and nonuse was defined as no prescription of PPIs during this period. Using national vital statistics in South Korea, we assessed the risk of all-cause mortality associated with concomitant PPI use through a propensity score-matched Cox proportional hazard model. Among 1646 patients included after 1:1 propensity score-matching, concomitant PPI use was associated with a 28% increased risk of all-cause mortality, compared to nonuse (adjusted hazard ratio [HR] 1.28; 95% confidence intervals [CIs], 1.13-1.46). We observed an increased risk when we restricted the analysis to new users of PPI (adjusted HR = 1.64; 95% CI = 1.25-2.17). Subgroup analysis showed that PPI use was associated with high mortality risk among patients with viral hepatitis (adjusted HR = 2.72; 95% CI = 1.54-4.78; P_interaction  = .048). Our study indicates that PPI use is associated with poor prognosis in NSCLC patients treated with ICIs. Further prospective studies are required to determine the risk-benefit balance of concomitant use of PPIs and ICIs.

The uninvited guests of our microbiome: Helicobacter pylori and Epstein-Barr virus and their role in gastric cancerogenesis

It is well established that human body is an ecosystem for numerous microorganisms: bacteria, fungi, eukaryotic parasites, and viruses. They form a “microbiome” that under conditions of homeostasis remains in a friendly mutual relationship with the host. However, the composition and diversity of this microbe community is dynamic and can be changed under the influence of environmental factors, such as diet, antibiotic therapy, lifestyle, and the host’s genotype and immunity. The result of gut microbiome dysbiosis can lead even to cancer. The aim of this review is the description of the healthy gastrointestinal microbiome and the role of two infectious agents: Gram-negative bacteria Helicobacter pylori and Epstein-Barr virus in the development of gastric cancer in terms of gut dysbiosis. H. pylori is the most important pathogen of gastric microbiome with clear impact on its diversity. Coinfection with Epstein-Barr virus causes chronic gastritis, and the inflammatory process is significantly increased. The process of carcinogenesis begins with chronic inflammation that causes atrophic gastritis, intestinal metaplasia, dysplasia, and finally cancer. It has been proven that chronic inflammatory infection caused by infectious agents increases the risk of stomach cancer. Molecular methods that are progressively used to explore the human microbiome provide hope that this knowledge will be used for future diagnoses and therapy in the state of its dysbiosis and in cases of gastric cancer.

Structural diversity, functional aspects and future therapeutic applications of human gut microbiome

The research on human gut microbiome, regarded as the black box of the human body, is still at the stage of infancy as the functional properties of the complex gut microbiome have not yet been understood. Ongoing metagenomic studies have deciphered that the predominant microbial communities belong to eubacterial phyla Firmicutes, Bacteroidetes, Proteobacteria, Fusobacteria, Cyanobacteria, Verrucomicrobia and archaebacterial phylum Euryarchaeota. The indigenous commensal microbial flora prevents opportunistic pathogenic infection and play undeniable roles in digestion, metabolite and signaling molecule production and controlling host's cellular health, immunity and neuropsychiatric behavior. Besides maintaining intestinal health via short-chain fatty acid (SCFA) production, gut microbes also aid in neuro-immuno-endocrine modulatory molecule production, immune cell differentiation and glucose and lipid metabolism. Interdependence of diet and intestinal microbial diversity suggests the effectiveness of pre- and pro-biotics in maintenance of gut and systemic health. Several companies worldwide have started potentially exploiting the microbial contribution to human health and have translated their use in disease management and therapeutic applications. The present review discusses the vast diversity of microorganisms playing intricate roles in human metabolism. The contribution of the intestinal microbiota to regulate systemic activities including gut-brain-immunity crosstalk has been focused. To the best of our knowledge, this review is the first of its kind to collate and discuss the companies worldwide translating the multi-therapeutic potential of human intestinal microbiota, based on the multi-omics studies, i.e. metagenomics and metabolomics, as ready solutions for several metabolic and systemic disorders.

The gastric microbiota in patients with Crohn's disease; a preliminary study

The gastric microbiota in Crohn's disease (CD) has not been studied. The purpose of the study was to evaluate differences of stomach microbiota between CD patients and controls. DNA was extracted from gastric mucosal and fluid samples, from 24 CD patients and 19 controls. 16S rRNA gene sequencing identified 1511 operational taxonomic units (OTUs), of which 239 passed the low abundance and low variance filters. All but one CD patients were HP negative. Fifteen bacterial phyla were identified in at least one mucosal or fluid site. Of these, Bacteroidota and Firmicutes accounted for 70% of all phyla. Proteobacteria, Actinobacteriota, and Fusobacteriota combined accounted for 27%. There was significant difference in the relative abundance of Bacteroidota, Proteobacteria, Fusobacteriota, and Campilobacterota between CD patients and controls only in gastric corpus samples. In gastric liquid, there was a significant difference only in Actinobacteriota. Pairwise comparison identified 67 differentially abundant OTUs in at least one site. Of these, 13 were present in more than one comparison, and four differentiating OTUs (Neisseriaceae, Neisseria, Absconditabacteriales, and Microbacteriaceae) were identified at all tested sites. The results reveal significant changes in gastric microbial profiles (beta diversity, phylum, and individual taxa levels) between H. pylori-negative CD patients and controls.

The pharmacotherapeutic management of duodenal and gastric ulcers

INTRODUCTION

Although the incidence and prevalence of duodenal and gastric ulcers have been declining, it remains challenging for health care systems. Based on the underlying cause, history, and characteristics of ulcers, management is generally provided by administering proton pump inhibitors (PPIs) or antibiotics.

AREAS COVERED

This article is based on global guidelines and English language literature from the past decade obtained through searches using PubMed, Clinicaltrials.gov, the US FDA, and the Cochrane library. Using a stepwise approach, dose and duration of treatment, drug interactions, warnings and contraindications, adverse effects, and administration points were specified. New drug candidates that may get American and European approvals were also introduced.

EXPERT OPINION

Despite the wide use of PPIs, their development lags behind the clinical need. There is an absolute requirement to develop third-generation PPIs with higher potency and improved pharmacokinetic and safety profiles. Regarding the antibiotic resistance crisis, including those used against H. pylori, conducting more clinical trials and investigating regional antibiotic resistance are warranted. Potassium competitive acid blockers, ilaprazole, and an H. pylori vaccine all show promise for the future.

Effect of an In Vitro Proximal Gastrointestinal Tract on Viability of Commercially Available Equine Probiotics

Probiotics, by definition, are live micro-organisms and should remain viable when they reach the intended site of action which is typically the cecum and/or colon. In humans, probiotics often need enteric protection to survive transit through the proximal gastrointestinal (GI) tract. Typically, equine probiotics do not advertise enteric protection and to the author's knowledge the viability of equine probiotics after exposure to the proximal GI tract has not been evaluated. The objective of this study was to evaluate the effect of an in vitro simulation of the equine proximal GI tract on probiotic viability. We hypothesized that the simulated proximal GI tract would adversely effect microbial viability and that the adverse effects would be partially ameliorated by increasing the gastric pH to 4. A total of 11 products were evaluated of which six had at least one micro-organism that was adversely effected by exposure to the proximal GI tract and four of which had at least one micro-organism that was adversely affected when the gastric pH was increased to 4.0. Results from this study indicate that some micro-organisms in equine probiotics do not appear to be adversely affected by exposure to the equine proximal GI tract.

Microbiological and genomic investigations of invasive Salmonella enterica serovar Panama from a large outbreak in Taiwan

BACKGROUND/PURPOSE

Salmonella Panama was considered an invasive non-typhoidal Salmonella (iNTS) serovar. Comprehensive clinical, microbiological, and genomic studies on S. Panama are scarce. We aimed to characterize the clinical and microbiological characteristics of S. Panama infection. Virulence mechanism of S. Panama and other iNTS serovars were also examined.

METHODS

Based on data from the longitudinal surveillance system for Salmonella deployed in Taiwan since 2004, a case-control study was undertaken to evaluate clinical characteristics of S. Panama infection during an outbreak in 2015-2016. Cellular experiments were conducted to compare pathogenicity of S. Panama and other iNTS with S. Typhimurium.

RESULTS

Most patients (41/44, 93.2%) infected by S. Panama were <5 years old (median, 1.3 years). The case-control study showed that 28 out of the 41 (68.3%) manifested as bacteremia, compared to S. Typhimurium (11.1%). Patients infected by S. Panama had longer durations of fever (P = 0.005) and hospitalization (P < 0.001). Genomic analyses split the isolates into three clades: two clones caused the outbreak, whereas another one accounted for the sporadic infections before 2015. Cellular experiments revealed that S. Panama and other iNTS serovars showed higher monolayer penetration and intracellular survival within macrophages, compared to S. Typhimurium.

CONCLUSION

This study confirmed that S. Panama is a clinically invasive serovar. Different iNTS serovars express common virulence phenotypes, but they may acquire invasiveness through distinct expression or combinations of virulence genes.

JianpiQinghua granule reduced PPI dosage in patients with nonerosive reflux disease: A multicenter, randomized, double-blind, double-dummy, noninferiority study

BACKGROUND

Proton pump inhibitors (PPIs) play an important role in the treatment of nonerosive reflux disease (NERD), but their long-term and excessive uses have been associated with safety concerns. Chinese herbal medicine (CHM) has become a popular alternative treatment for this condition.

METHODS

A total of 204 patients were randomly assigned to the combination group or PPI group (1:1 ratio). They were given JianpiQinghua (JQ) granules (34.8 g) plus omeprazole (10 mg) plus dummy omeprazole (10 mg) or dummy JQ granules (34.8 g) plus omeprazole (20 mg) daily for 4 weeks. The primary endpoints were the rate of sufficient relief and complete resolution of GERD Q at week 4. Metabonomics and the gut microbiota were also assessed.

RESULTS

Complete resolution was observed in 40.8% of patients in the combination group and 26.8% of patients in the PPI group after 4 weeks (FAS analysis, OR, 1.88; 95% CI, 1.03-3.44; p = 0.039). Sufficient relief was observed in 50% of patients in the combination group and 43.30% of patients in the PPI group after 4 weeks (FAS analysis, OR, 1.31; 95% CI, 0.74-2.30; p = 0.35). Three patients had liver dysfunction, one of whom had a mild case and 2 of whom had moderate-to-severe cases in the combination group. Patients in the combination group showed a significant increase in richness and diversity of their gut microbiota compared with those in the PPI group. Metabonomics showed that the combination therapy could correct the glutamate metabolism pathway.

CONCLUSION

Our findings demonstrate the superior efficacy of JQ granules combined with omeprazole (10 mg) vs. omeprazole (20 mg) in terms of symptom relief in patients with NERD.

TRIAL REGISTRATION

ClinicalTrials.gov number NCT02892357. Registered on 14 February 2019.

APB-13 improves the adverse outcomes caused by TGEV infection by correcting the intestinal microbial disorders in piglets

Porcine transmissible gastroenteritis virus (TGEV) is an enteric coronavirus that has caused high morbidity and mortality of piglets worldwide. Previous studies have shown that the TGEV can lead to severe diarrhoea, vomiting and dehydration in 2-week-old piglets and weaned piglets, resulting in a large number of piglet deaths. Antimicrobial peptides have broad-spectrum antimicrobial activity and a strong killing effect on bacteria, especially on the drug-resistant pathogenic bacteria, and it has attracted broad concern. However, there are very few reports on the effect of APB-13 (an antimicrobial peptide) on the intestinal microbes of piglets infected with TGEV. In this study, 16S rRNA gene sequencing was used to compare the microbial phylum and the genus of piglet's enteric microorganism in different experimental groups, and to predict the metabolic function of the microbial flora. At the same time, the apparent digestibility of nutrients, digestive enzyme activity, daily weight gain and survival rate were also measured. TGEV infection could cause the imbalance of intestinal microbes in piglets, and increase of the relative abundance of Proteobacteria, and decrease of the relative abundance of Firmicutes, Bacteroidetes and Actinobacteri. With the addition of APB-13, this problem can be alleviated, which can reduce the relative abundance of Proteobacteria and improve the balance of intestinal microorganisms. At the microbial genus level, after adding APB-13, the relative abundance of Catenibacterium, Enterobacter and Streptococcus in the intestinal tract of piglets infected with TGEV showed significant decrease, while the relative abundance of Lactobacillus and Ruminococcus increased. Finally, we found that APB-13 can significantly increase the activity of digestive enzyme in the intestinal tract of piglet, thereby improving the apparent digestibility of nutrients and the growth performance of piglets. This study demonstrates that APB-13 can alleviate the adverse outcomes caused by TGEV infection by correcting the intestinal microbial disorders.

Risk of peritonitis after gastroscopy in peritoneal dialysis patients

BACKGROUND

Peritonitis is a common and serious complication of peritoneal dialysis (PD). Translocation of gut bacteria to peritoneum is an important mechanism, which may be enhanced by gastrointestinal endoscopy.

METHODS

In this retrospective observational cohort study, we identified 450 gastroscopies performed in PD patients within a single centre between 2014 and 2019. Gastroscopy-related peritonitis was defined by peritonitis within 1 week after endoscopy.

RESULTS

A total of 408 endoscopic episodes in 216 patients were analysed after excluding 42 cases with either pre-existing peritonitis before endoscopy, or concomitant biliary, small bowel or large bowel endoscopy. There were 16 episodes of peritonitis within 1 week of endoscopy (3.9%). One-quarter of cases were polymicrobial (four episodes, 25.0%). Logistic regression model showed that patient's age, number of endoscopic biopsies, and histamine-2 receptor blocker use were independently associated with peritonitis, while prior antibiotics exposure was associated with lower risk of peritonitis, odds ratio 0.23 (95% confidence interval 0.06-0.95; p = 0.04).

CONCLUSION

Peritonitis can complicate gastroscopy in PD patients and occurs more often in elderly or after repeated biopsy procedures.

Impact of the repurposed drug thonzonium bromide on host oral-gut microbiomes

Drug repurposing is a feasible strategy for the development of novel therapeutic applications. However, its potential use for oral treatments and impact on host microbiota remain underexplored. Here, we assessed the influences of topical oral applications of a repurposed FDA-approved drug, thonzonium bromide, on gastrointestinal microbiomes and host tissues in a rat model of dental caries designed to reduce cross-contamination associated with coprophagy. Using this model, we recapitulated the body site microbiota that mirrored the human microbiome profile. Oral microbiota was perturbed by the treatments with specific disruption of Rothia and Veillonella without affecting the global composition of the fecal microbiome. However, disturbances in the oral-gut microbial interactions were identified using nestedness and machine learning, showing increased sharing of oral taxon Sutterella in the gut microbiota. Host-tissue analyses revealed caries reduction on teeth by thonzonium bromide without cytotoxic effects, indicating bioactivity and biocompatibility when used orally. Altogether, we demonstrate how an oral treatment using a repurposed drug causes localized microbial disturbances and therapeutic effects while promoting turnover of specific oral species in the lower gut in vivo.

Effect of Bacillus clausii Capsules in Reducing Adverse Effects Associated with Helicobacter pylori Eradication Therapy: A Randomized, Double-Blind, Controlled Trial

INTRODUCTION

Antibiotic treatment can alter the gut microbiome and cause short-term gastrointestinal adverse effects (AEs). This study assessed the efficacy of lyophilized capsules containing 2 × 109 spores of Bacillus clausii (Enterogermina®; Sanofi Synthelabo) in reducing AEs associated with Helicobacter pylori eradication therapy in Italy.

METHODS

In this randomized, double-blind, single-center, phase IIIB study, 130 adult outpatients with H. pylori infection were assigned to receive one Enterogermina® capsule or placebo three times daily for 2 weeks (1:1). During week 1, all patients received clarithromycin 500 mg, amoxicillin 1 g, and rabeprazole 20 mg twice daily. The primary efficacy outcome was the presence of diarrhea in week 1.

RESULTS

A total of 130 patients were randomized. The incidence of diarrhea in week 1 was 29% in the B. clausii group and 48% in the placebo group [relative risk (RR) 0.61; 95% confidence interval (CI) 0.39-0.97; p = 0.03]. The incidence of diarrhea remained lower with B. clausii than with placebo in week 2 (RR 0.38; 95% CI 0.14-1.02; p = 0.0422). In week 1, the number of days without diarrhea was significantly higher in the B. clausii group than in the placebo group (6.25 vs. 5.86; p = 0.0304). In both groups, the number of days without diarrhea increased significantly (p < 0.0001) from week 1 to week 2. A total of three AEs occurred in two patients in the placebo group, but none were serious.

CONCLUSIONS

Compared with placebo, Enterogermina® reduced the incidence of, and the number of days with, diarrhea in patients receiving H. pylori eradication therapy. Enterogermina® was well tolerated.

Long-term effects of antimicrobial drugs on the composition of the human gut microbiota

INTRODUCTION

Antimicrobial drugs are known to have effects on the human gut microbiota. We studied the long-term temporal relationship between several antimicrobial drug groups and the composition of the human gut microbiota determined in feces samples.

METHODS

Feces samples were obtained from a community-dwelling cohort of middle-aged and elderly individuals (Rotterdam Study). Bacterial DNA was isolated and sequenced using V3/V4 16 S ribosomal RNA sequencing (Illumina MiSeq). The time between the last prescription of several antimicrobial drug groups and the day of sampling was categorized into 0-12, 12-24, 24-48 and >48 months. The effects of the antimicrobial drug groups on the Shannon alpha-diversity (diversity), the Bray-Curtis beta-diversity (community structure), the Firmicutes/Bacteroidetes (F/B) ratio and individual genera were determined.

RESULTS

We studied the gut microbiota of 1413 individuals (57.5% female, median age 62.6 years). The alpha-diversity was significantly lower up to 4 years after prescriptions of macrolides and lincosamides. It was also lower in the first year after the use of beta-lactams. The community structure (beta-diversity) of the microbiota was significantly different up to 4 years for macrolides and lincosamides, the first year for beta-lactams and at least the first year for quinolones. For the F/B ratio, drugs with a high anaerobic activity shifted the ratio toward Firmicutes in the first year whereas other antimicrobial drugs shifted the ratio toward Bacteroidetes.

CONCLUSION

Use of antimicrobial drugs is associated with a shift in the composition of the gut microbiota.These effects differ in strength and duration, depending on the antimicrobial drug group used. These findings should be considered when prescribing antimicrobial drugs.

Helicobacter pylori Related Diseases and Osteoporotic Fractures (Narrative Review)

Osteoporosis (OP) and osteoporotic fractures (OFs) are common multifactorial and heterogenic disorders of increasing incidence. Helicobacter pylori (H.p.) colonizes the stomach approximately in half of the world's population, causes gastroduodenal diseases and is prevalent in numerous extra-digestive diseases known to be associated with OP/OF. The studies regarding relationship between H.p. infection (HPI) and OP/OFs are inconsistent. The current review summarizes the relevant literature on the potential role of HPI in OP, falls and OFs and highlights the reasons for controversies in the publications. In the first section, after a brief overview of HPI biological features, we analyze the studies evaluating the association of HPI and bone status. The second part includes data on the prevalence of OP/OFs in HPI-induced gastroduodenal diseases (peptic ulcer, chronic/atrophic gastritis and cancer) and the effects of acid-suppressive drugs. In the next section, we discuss the possible contribution of HPI-associated extra-digestive diseases and medications to OP/OF, focusing on conditions affecting both bone homeostasis and predisposing to falls. In the last section, we describe clinical implications of accumulated data on HPI as a co-factor of OP/OF and present a feasible five-step algorithm for OP/OF risk assessment and management in regard to HPI, emphasizing the importance of an integrative (but differentiated) holistic approach. Increased awareness about the consequences of HPI linked to OP/OF can aid early detection and management. Further research on the HPI-OP/OF relationship is needed to close current knowledge gaps and improve clinical management of both OP/OF and HPI-related disorders.

Acid-suppressive medications and risk of colorectal cancer: results from three large prospective cohort studies

BACKGROUND

Despite several plausible biological mechanisms linking proton pump inhibitors (PPIs) and H2 receptor antagonists (H2RAs) with colorectal tumorigenesis, their association with risk of colorectal cancer (CRC) has not been adequately assessed in prospective epidemiological studies.

METHODS

We evaluated the association of acid-suppressive medication use with CRC risk among 175,871 (PPI) and 208,831 (H2RA) participants from three large prospective cohort studies. Medication use was assessed at baseline and updated biennially. The association was evaluated using multivariate Cox proportional hazards regression models.

RESULTS

There was no significant association between baseline PPI use (hazard ratio (HR) = 0.89, 95% confidence interval (CI), 0.71-1.12) or PPI use after a lag of 8-10 years (HR = 1.12, 95% CI, 0.78-1.59) with CRC risk. We observed no significant association between H2RA use after a lag of 8-10 years and CRC risk (HR = 1.02, 95% CI, 0.81-1.28), while risk was lower for participants with baseline H2RA use (HR = 0.76, 95% CI, 0.60-0.95). Duration of PPI use or H2RA use was not associated with CRC risk (P-trend = 0.21 and 0.95, respectively).

CONCLUSIONS

Among participants from three large prospective cohorts, use of PPI or H2RA was not associated with higher risk of colorectal cancer.

Potential proton pump inhibitor-related adverse effects

Proton pump inhibitors (PPIs) are one of the most common medications taken by patients worldwide. PPIs are used to treat acid-related disorders, including gastroesophageal reflux disease, peptic ulcer disease, Helicobacter pylori infection, and nonsteroidal anti-inflammatory drug/stress ulceration. For some of these diseases, long-term treatment is necessary. With such prolonged use, concern and investigation into potential adverse effects has increased. In addition, data are available regarding potential anticancer effects of PPIs, especially regarding solid tumors. The aim of this review is to assess the literature on PPIs with regard to common concerns, such as drug-drug interactions, the intestinal microbiome, dementia and central nervous system disease, and osteoporosis, as well as to highlight potential negative and positive impacts of the drug in cancer.

Latest insights into the hot question of proton pump inhibitor safety - a narrative review

Proton pump inhibitors (PPIs) are among the most widely prescribed medications worldwide and their use is continuously increasing. Although they have been shown to combine high therapeutic efficacy and good safety profile in many studies, in last years we have witnessed the publication of many articles reporting the possible association of long-term PPI therapy with important unexpected adverse events and these observations have created alarmism in both patients and physicians. However, the majority of these studies are observational, retrospective and prone to residual confounding. Also, the odds ratio values are generally comprised between 1 and 2 and therefore devoid of strong clinical relevance. As it is unlikely that prospective randomized trials will be ever done to reinforce these associations, we can only attempt to distinguish clear- from unclear-defined adverse events from the available literature. Nowadays we can reasonably exclude cardiovascular diseases, community-acquired pneumonia, all-cause mortality, dementia and bone fractures from PPI-related adverse events. However, physicians should be aware of the existence of possible risks when treating their patients, especially the elderly and frail ones, with long-term PPIs, which should be prescribed only to persons with defined indications and at lowest dose and duration.

Fullerenol Nanoparticles Eradicate Helicobacter pylori via pH-Responsive Peroxidase Activity

Helicobacter pylori (H. pylori) eradication by antibiotics and proton pump inhibitor treatment is limited by the low pH microenvironment in the stomach and can lead to antibiotic resistance. We fabricated fullerenol nanoparticles (FNPs) with varied chemical structures responding to a pinacol rearrangement of vicinal hydroxyl to form carbonyls in low pH environments. An obvious increase in C═O/C-O was induced in low pH and was positively correlated with a peroxidase-like activity. The FNPs exerted an excellent effect on H. pylori eradication in vitro and in vivo because of their peroxidase-like activity. FNP treatment of a H. pylori biofilm revealed that FNPs broke down polysaccharides in cell wall components, resulting in collapse of the bacteria. The cycles of FNPs combining and dissociating with the peroxidase substrate were detected by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and confirmed that FNPs enhance peroxidase-like activity. Further, the isothermal titration calorimetry results showed that FNPs with more C═O/C-O had greater affinity to bind the peroxidase substrates. Therefore, we suggest that varied C═O/C-O serves as a switch to respond to low pH in the stomach to kill H. pylori by inducing a peroxidase-like activity. FNPs can also overcome the challenge of antibiotic resistance to achieve H. pylori eradication in the stomach.

The Exopolysaccharide of Lactobacillus fermentum UCO-979C Is Partially Involved in Its Immunomodulatory Effect and Its Ability to Improve the Resistance against Helicobacter pylori Infection

Lactobacillus fermentum UCO-979C (Lf979C) beneficially modulates the cytokine response of gastric epithelial cells and macrophages after Helicobacter pylori infection in vitro. Nevertheless, no in vivo studies were performed with this strain to confirm its beneficial immunomodulatory effects. This work evaluated whether Lf979C improves protection against H. pylori infection in mice by modulating the innate immune response. In addition, we evaluated whether its exopolysaccharide (EPS) was involved in its beneficial effects. Lf979C significantly reduced TNF-α, IL-8, and MCP-1 and augmented IFN-γ and IL-10 in the gastric mucosa of H. pylori-infected mice. The differential cytokine profile induced by Lf979C in H. pylori-infected mice correlated with an improved reduction in the pathogen gastric colonization and protection against inflammatory damage. The purified EPS of Lf979C reduced IL-8 and enhanced IL-10 levels in the gastric mucosa of infected mice, while no effect was observed for IFN-γ. This work demonstrates for the first time the in vivo ability of Lf979C to increase resistance against H. pylori infection by modulating the gastric innate immune response. In addition, we advanced knowledge of the mechanisms involved in the beneficial effects of Lf979C by demonstrating that its EPS is partially responsible for its immunomodulatory effect.

Microbiome and Gastric Cancer

The late 1800s Louis Pasteur and Robert Koch introduced and popularized the germ theory of disease. At that time, gastric cancer was the most common cause of cancer deaths in most countries making the stomach an early site of microbial research with a focus on gastric luminal and mucosal bacteria and the role of Boas-Oppler bacillus (Lactobacillus) in the diagnosis of gastric cancer. In the 1970s, the research focus evolved to studies of the gastric microbiome in the production of nitrosamines and included development of the Correa cascade. Interest in nitrosamine production peaked in the late 1980s and was replaced by studies of the newly described Helicobacter pylori and studies of its role in gastritis, gastric atrophy, and gastric cancer. The last decade has witnessed a rebirth in interest in the gastric microbiota as part of worldwide interest in the human microbiome. Although fungi were prominent in the studies of gastric microbiology in the nineteenth century, their potential role in disease pathogenesis has yet to be addressed using modern techniques. Overall, current studies of the gastric bacterial microbiome do not provide convincing evidence to expand the role of the gastric microbiome in cancer pathogenesis beyond what is directly attributable to the oncogenic potential of H. pylori and its role in persisting acute-on-chronic inflammation.

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.

Dysbiosis of the gut and lung microbiome has a role in asthma

Worldwide 300 million children and adults are affected by asthma. The development of asthma is influenced by environmental and other exogenous factors synergizing with genetic predisposition, and shaping the lung microbiome especially during birth and in very early life. The healthy lung microbial composition is characterized by a prevalence of bacteria belonging to the phyla Bacteroidetes, Actinobacteria, and Firmicutes. However, viral respiratory infections are associated with an abundance of Proteobacteria with genera Haemophilus and Moraxella in young children and adult asthmatics. This dysbiosis supports the activation of inflammatory pathways and contributes to bronchoconstriction and bronchial hyperresponsiveness. Exogenous factors can affect the natural lung microbiota composition positively (farming environment) or negatively (allergens, air pollutants). It is evident that also gut microbiota dysbiosis has a high influence on asthma pathogenesis. Antibiotics, antiulcer medications, and other drugs severely impair gut as well as lung microbiota. Resulting dysbiosis and reduced microbial diversity dysregulate the bidirectional crosstalk across the gut-lung axis, resulting in hypersensitivity and hyperreactivity to respiratory and food allergens. Efforts are undertaken to reconstitute the microbiota and immune balance by probiotics and engineered bacteria, but results from human studies do not yet support their efficacy in asthma prevention or treatment. Overall, dysbiosis of gut and lung seem to be critical causes of the increased emergence of asthma.

Proton pump inhibitors and histamine-2 receptor antagonists on the risk of pancreatic cancer: a systematic review and meta-analysis

BACKGROUND

Proton pump inhibitors (PPI) and histamine-2 receptor antagonists (H2RA) have been widely used for multiple purposes. Recent studies have suggested an association between these medications and the risk of pancreatic cancer. However, the results have been inconclusive.

AIM

We, therefore, conducted a study to assess the risk of developing pancreatic cancer in patients who used PPI and H2RA.

DESIGN

A systematic review and meta-analysis.

METHODS

A literature search was performed using MEDLINE and EMBASE databases from inception through February 2019. Studies that reported risk ratio comparing the risk of pancreatic cancer in patients who received PPI or H2RA versus those who did not receive treatments were included. Pooled risk ratios (RR) and 95% confidence intervals (CI) were calculated using a random-effect generic inverse variance method. Sensitivity analysis, excluding one study at a time, was performed.

RESULTS

After screening abstracts from the searching methods, seven studies (six case-control studies and one cohort study) were included in the analysis with total 546 199 participants. Compared to patients who did not take medications, the pooled RR of developing pancreatic cancer in patients receiving PPI and H2RA were 1.73 (95% CI: 1.16-2.57) and 1.26 (95% CI: 1.02-1.57), respectively. However, the sensitivity analysis of PPI changed the pooled RR to 1.87 (95% CI: 1.00-3.51) after a study was dropped out. Likewise, H2RA sensitivity analysis also resulted in non-significant pooled RR.

CONCLUSIONS

This meta-analysis did not find the strong evidence for the associations between the use of PPI and H2RA and pancreatic cancer.

The Association between ABCB1 C1236T/C3435T SNPs and H. pylori Infection among Jordanians

Infection with Helicobacter pylori (H. pylori) is very common and affecting about 50% of the worldwide population. Several genetic variations have been implicated in determining the clinical susceptibility to this infection. In the current study, we examined the association between C1236T (rs1045642) and C3435T (rs1045642) single nucleotide polymorphisms (SNPs) in the ABCB1 gene and the prevalence of H. pylori infection among Jordanians. A total of 412 subjects (257 H. pylori-positive cases and 155 H. pylori-negative controls) were recruited and participated in the study, and the genotyping of the ABCB1 gene was performed using RFLP-PCR techniques. A significant association was detected between C1236T and H. pylori infection (p < 0.01). The frequency of CT genotype was significantly higher in the positive cases (40.1%) compared to the controls (21.3%). In addition, the C3435T SNP was weakly associated with H. pylori infection (p = 0.077). Haplotype analysis of C1236T and C3435T SNPs showed that the TT haplotype was present in 22.7% of the positive cases compared to 30.7% of the negative controls (p < 0.05, odds ratio = 0.663, 95% CI: (0.483-0.911)). Consequently, the TT haplotype seems to decrease the risk of H. pylori infection. In conclusion, the current results suggest an association between ABCB1 SNPs and H. pylori infection in the Jordanian population.