Helicobacter pylori and functional dyspepsia: An unsolved issue?

MODERN APPROACH TO DYSPEPSIA

Dyspepsia is a disorder characterized by dyspeptic symptoms which are located in the epigastrium and related to digestion of food in the initial part of the digestive system. In functional dyspepsia, unlike organic dyspepsia, there is no underlying organic disease that would cause dyspeptic symptoms. Immune and mucosal function changes, gastric dysmotility, different composition of the gastrointestinal microbiota, and altered central nervous system processing are considered responsible for the onset of the disorder. The diagnosis is based on history, clinical presentation, and exclusion of other organic diseases of the gastrointestinal tract manifested by dyspeptic symptoms. Therapy includes eradication of Helicobacter pylori infection, proton pump inhibitors, prokinetics, neuromodulators, and herbal preparations. Unfortunately, in some patients, this therapy leads to little or no improvement. The prevalence of functional dyspepsia is increasing. It has become one of the more common gastroenterological diagnoses. In order to reduce the costs associated with the diagnosis and treatment of the disorder itself, its mechanisms need to be fully elucidated and thus enable finding appropriate therapy for all patient subgroups.

The Usefulness of Symptom-based Subtypes of Functional Dyspepsia for Predicting Underlying Pathophysiologic Mechanisms and Choosing Appropriate Therapeutic Agents

Functional dyspepsia (FD) is considered to be a heterogeneous disorder with different pathophysiological mechanisms or pathogenetic factors. In addition to traditional mechanisms, novel concepts regarding pathophysiologic mechanisms of FD have been proposed. Candidates of therapeutic agents based on novel concepts have also been suggested. FD is a symptom complex and currently diagnosed by symptom-based Rome criteria. In the Rome criteria, symptom-based subtypes of FD including postprandial distress syndrome and epigastric pain syndrome are recommended to be used, based on the assumption that each subtype is more homogenous in terms of underlying pathophysiologic mechanisms than FD as a whole. In this review, the usefulness of symptombased subtypes of FD for predicting underlying pathophysiologic mechanisms and choosing appropriate therapeutic agents was evaluated. Although several classic pathophysiologic mechanisms are suggested to be associated with individual dyspeptic symptoms, symptom-based subtypes of FD are not specific for a certain pathogenetic factor or pathophysiologic mechanism, and may be frequently associated with multiple pathophysiologic abnormalities. Novel concepts on the pathophysiology of FD show complex interactions between pathophysiologic mechanisms and pathogenetic factors, and prediction of underlying mechanisms of individual patients simply by the symptom pattern or symptom-based subtypes may not be accurate in a considerable proportion of cases. Therefore, subtyping by the Rome criteria appears to have limited value to guide therapeutic strategy, suggesting that the addition of objective parameters or subclassification reflecting physiologic or pathologic tests may be necessary for the targeted therapeutic approaches, particularly when therapeutic agents targeting novel mechanisms are available.

Relationship Between Helicobacter pylori Infection, Serum Vitamin D3 Level and Spontaneous Abortion

Background

The effects of vitamin D3 (VD3) on pregnancy outcomes remain obscure. Thus, this study aims to investigate the relationship between maternal H. pylori infection, low VD3 level, and spontaneous abortion.

Methods

This research is conducted in Shahid Ali Qader Consultant Clinic in Sulaimaniyah city in which 100 women with a history of abortion and 100 women with no history of miscarriage were included. Serum detection of anti-H. pyloriIgG, IgA, and VD3 were done using enzyme-linked immunosorbent assay (ELISA) technique.

Results

The mean of VD3, H. pylori IgG, and IgAin patients and control group cases was determined and analyzed statistically.

Conclusion

H. pylori infection and VD3 play a significant role in early pregnancy loss. Blood group A and O are more prone to spontaneous abortion.

The Comparison of Levofloxacin- and Clarithromycin-Based Bismuth Quadruple Therapy Regimens in Helicobacter pylori Eradication

OBJECTIVE

The aim of the current study was to compare the efficacy of quadruple therapy including levofloxacin and clarithromycin for Helicobacter pylori eradication.

METHODS

This clinical trial study was conducted on 189 patients with H. pylori infection who underwent gastroscopy and stomach biopsy in Shahid Beheshti Hospital, Kashan, Iran. After classification of patients, one group was treated with bismuth subcitrate (120 mg, 2 tablet/12 h), omeprazole (20 mg/12 h), amoxicillin (1 g/12 h), and clarithromycin (500 mg/12 h) and other group with bismuth subcitrate (120 mg, 2 tablet/12 h), omeprazole (20 mg/12h), amoxicillin (1 g/12 h), and levofloxacin (500 mg/12 h) for 2 weeks. After the end of the antibiotic treatment, omeprazole therapy was continued for 4 weeks. Two weeks after discontinuation of omeprazole, fecal antigen test was performed for both the groups to confirm the eradication of H. pylori infection.

FINDINGS

The success of H. pylori eradication in the levofloxacin and clarithromycin groups was observed in 78 (89.7%) and 71 (69.6%) patients, respectively (P < 0.01). A significant difference was also seen between the two groups in terms of side effects and its incidence (P < 0.01), so that the incidence of side effect types in the clarithromycin group was more than the levofloxacin group except muscular pain and fatigue (P < 0.01).

CONCLUSION

Levofloxacin-based quadruple regimen therapy was superior to clarithromycin-based quadruple regimens regarding H. pylori eradication and side effects. Therefore, the levofloxacin-based regimen can be considered as an effective treatment for the first-line anti-H. pylori therapy.

Vonoprazan and Helicobacter pylori Treatment: A Lesson From Japan or a Limited Geographic Phenomenon?

Within a short time after the discovery of Helicobacter pylori, its critical role in many gastroduodenal disorders became evident. Many in vitro and in vivo data have proven that infection should be treated in order to avoid lasting colonization which may lead to problematic gastroduodenal diseases. Probiotics, preventive and therapeutic vaccines and antibiotic therapy are the main options proposed to cure these disorders. 25 years ago, triple therapy including a traditional proton pump inhibitor (PPI) and two antibiotics (amoxicillin and clarithromycin or metronidazole) was defined as the best therapy formulation for the H. pylori infection. With the strongly decreased effectiveness of this scheme, many empirical therapeutic regimens have been developed. However, the prevalence of resistance is increasing worldwide and reveals important geographic differences and even the most recent and effective regimens show some critical points. Therefore, efficacy of vonoprazan-based therapy in regions with low rate of clarithromycin resistance may be limited. In this review, we attempt to open a new window to overcome the problem of antibiotic resistance to H. pylori. In fact, we focused our attention on the possibility that conventional PPI may be replaced by vonoprazan, thus giving rise to the beginning of a new era characterized by an improved therapeutic option for H. pylori infection. Therefore, we hypothesize that switching to vonoprazan as a novel acid blocker for H. pylori treatment might allow an unexpected reassessment of the triple therapy, at least in regions with low rate of clarithromycin resistance. Nevertheless, this optimistic view of the problem could be disproved by the possible failure of vonoprazan based therapeutic regimens outside of Japan in geographic areas characterized by different rates of antibiotic resistances.

A comparison of techniques to address the frequency of Helicobacter pylori positive dyspeptic patient

Objectives

The study was aimed to compare the diagnostic techniques, for the detection of Helicobacter pylori infection, available in low-income countries, where molecular testing is not available or inaccessible to anyone.

Results

Of total enrolled patient, with the mean age of 41.4 ± 13.33 years, 24 (14 female; 10 male) were diagnosed to have been infected. The diagnosis was established based upon the gold standard test [either two of three tests: Rapid Urease Test (RUT), culture and histological examinations]. Of clinical presentation, the epigastric pain (75%) was the commonest; nevertheless, the endoscopic findings had shown an equivocal specificity since the larger percentile (58.3%) reported as normal findings, in a presumed dyspepsia. Based on the premise—with calculated sensitivity, specificity, and predictive values; the accuracy order observed as histology > RUT > serology > stool antigen test, in H. pylori detection from the clinical samples. The accuracy order of the diagnostic test may vary depending upon the laboratory settings and study population. Therefore, in reference to low-income countries, the clinicians must resort any available positive test so that the supporting positive rudiments would be an ancillary in augmenting the diagnostic accuracy.

Certain Dietary Habits Contribute to the Functional Dyspepsia in South China Rural Area

BACKGROUND Functional dyspepsia (FD) refers to a group of upper gastrointestinal syndromes, subdivided into two types: postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS). The etiology of FD remains unclear; however, unhealthy dietary habit is one potential underlying cause. We aim to explore the association of poor dietary habits with FD and its subtypes. MATERIAL AND METHODS A validated epidemiological questionnaire was designed to investigate dietary habits and gastrointestinal syndromes. Citizens in the Baotun community of Dongguan were invited to complete the study questionnaire. All participants were asked to undergo a physical examination and a blinded physician interview. The study was conducted from June 2015 to June 2016. FD was diagnosed using ROME III criteria. The association between investigated dietary habits and dyspeptic symptoms were explored. RESULTS There were 1,304 adult residents recruited for the study survey; 165 residents had existing organic dyspepsia (OD), 203 residents were diagnosed with FD, and the other 936 participants, who were without dyspeptic symptoms or functional gastrointestinal diseases, were regarded as the control group. Subtype diagnosis indicated 61 participants had EPS, 66 participants had PDS, and 76 participants had coexisting EPS and PDS. Unhealthy dietary habits were more prevalent in the FD group than in the control groups (75.86% versus 37.50%; p<0.001). FD was found to be associated with irregular mealtime, dining out, fatty food, sweet food, and coffee (p<0.05). The impact of each dietary factor varied with FD subtypes. CONCLUSIONS Certain types of dietary habits were positively correlated with the prevalence of FD. FD subtypes showed relatively different associations with dietary factors.

Noninvasive molecular analysis of Helicobacter pylori: Is it time for tailored first-line therapy?

The main problem of Helicobacter pylori (H. pylori) infection management is linked to antibiotic resistances. This phenomenon has grown in the last decade, inducing a dramatic decline in conventional regimen effectiveness. The causes of resistance are point mutations in bacterial DNA, which interfere with antibiotic mechanism of action, especially clarithromycin and levofloxacin. Therefore, international guidelines have recently discouraged their use in areas with a relevant resistance percentage, suggesting first-line schedules with expected high eradication rates, i.e., bismuth containing or non-bismuth quadruple therapies. These regimens require the daily assumption of a large number of tablets. Consequently, a complete adherence is expected only in subjects who may be motivated by the presence of major disorders. However, an incomplete adherence to antibiotic therapies may lead to resistance onset, since sub-inhibitory concentrations could stimulate the selection of resistant mutants. Of note, a recent meta-analysis suggests that susceptibility tests may be more useful for the choice of first than second-line or rescue treatment. Additionally, susceptibility guided therapy has been demonstrated to be highly effective and superior to empiric treatments by both meta-analyses and recent clinical studies. Conventional susceptibility test is represented by culture and antibiogram. However, the method is not available everywhere mainly for methodology-related factors and fails to detect hetero-resistances. Polymerase chain reaction (PCR)-based, culture-free techniques on gastric biopsy samples are accurate in finding even minimal traces of genotypic resistant strains and hetero-resistant status by the identification of specific point mutations. The need for an invasive endoscopic procedure has been the most important limit to their spread. A further step has, moreover, been the detection of point mutations in bacterial DNA fecal samples. Few studies on clarithromycin susceptibility have shown an overall high sensitivity and specificity when compared with culture or PCR on gastric biopsies. On these bases, two commercial tests are now available although they have shown some controversial findings. A novel PCR method showed a full concordance between tissue and stool results in a preliminary experience. In conclusion, despite poor validation, there is increasing evidence of a potential availability of noninvasive investigations able to detect H. pylori resistances to antibiotics. These kinds of analysis are currently at a very early phase of development and caution should be paid about their clinical application. Only further studies aimed to evaluate their sensitivity and specificity will afford novel data for solid considerations. Nevertheless, noninvasive molecular tests may improve patient compliance, time/cost of infection management and therapeutic outcome. Moreover, the potential risk of a future increase of resistance to quadruple regimens as a consequence of their use on large scale and incomplete patient adherence could be avoided.

Effects of Proton Pump Inhibitors on the Gastric Mucosa-Associated Microbiota in Dyspeptic Patients

Besides being part of anti-Helicobacter pylori treatment regimens, proton pump inhibitors (PPIs) are increasingly being used to treat dyspepsia. However, little is known about the effects of PPIs on the human gastric microbiota, especially those related to H. pylori infection. The goal of this study was to characterize the stomach microbial communities in patients with dyspepsia and to investigate their relationships with PPI use and H. pylori status. Using 16S rRNA gene pyrosequencing, we analyzed the mucosa-associated microbial populations of 24 patients, of whom 12 were treated with the PPI omeprazole and 9 (5 treated and 4 untreated) were positive for H. pylori infection. The Proteobacteria, Firmicutes, Bacteroidetes, Fusobacteria, and Actinobacteria phyla accounted for 98% of all of the sequences, with Helicobacter, Streptococcus, and Prevotella ranking among the 10 most abundant genera. H. pylori infection or PPI treatment did not significantly influence gastric microbial species composition in dyspeptic patients. Principal-coordinate analysis of weighted UniFrac distances in these communities revealed clear but significant separation according to H. pylori status only. However, in PPI-treated patients, Firmicutes, particularly Streptococcaceae, were significantly increased in relative abundance compared to those in untreated patients. Consistently, Streptococcus was also found to significantly increase in relation to PPI treatment, and this increase seemed to occur independently of H. pylori infection. Our results suggest that Streptococcus may be a key indicator of PPI-induced gastric microbial composition changes in dyspeptic patients. Whether the gastric microbiota alteration contributes to dyspepsia needs further investigation.

IMPORTANCE

Although PPIs have become a popular treatment choice, a growing number of dyspeptic patients may be treated unnecessarily. We found that patients treated with omeprazole showed gastric microbial communities that were different from those of untreated patients. These differences regarded the abundances of specific taxa. By understanding the relationships between PPIs and members of the gastric microbiota, it will be possible to envisage new strategies for better managing patients with dyspepsia.

Effects of Lactobacillus gasseri OLL2716 on Helicobacter pylori-Associated Dyspepsia: A Multicenter Randomized Double-Blind Controlled Trial

Some Lactobacillus spp. suppress Helicobacter pylori in the stomach and have potential therapeutic applications for the treatment of gastrointestinal conditions. In this study, the effects of Lactobacillus strains on functional dyspepsia associated with H. pylori infection were examined. Volunteers were screened using the ¹³C-urea breath test (UBT) and H. pylori stool test, and 131 participants who met the selection criteria (mean age: 48.9 years) were randomly given L. gasseri OLL2716-containing yogurt or placebo yogurt once daily for 12 weeks. Gastrointestinal symptoms (epigastric pain, bloating, postprandial fullness, nausea, and heartburn) and the levels of serum pepsinogen (PG), ¹³C-UBT, and H. pylori stool antigen were assessed. No significant differences were observed between the groups in UBT results, H. pylori stool antigens, or the serum PGI/II ratio. In the L. gasseri group, postprandial fullness was significantly lower at the end of the trial compared to the initial level (p < 0.05) and significantly fewer patients had a VAS score of >10 for bloating compared to the placebo group (p < 0.05). Dietary supplementation with L. gasseri OLL2716-containing yogurt may effectively suppress dyspeptic symptoms in H. pylori-infected patients. This study was registered at the University Hospital Medical Network Clinical Trial Registry (UMIN000016746).

Functional dyspepsia: new insights into pathogenesis and therapy

One in 10 people suffer from functional dyspepsia (FD), a clinical syndrome comprising chronic bothersome early satiety, or postprandial fullness, or epigastric pain or burning. Postprandial distress syndrome (PDS, comprising early satiety and/or postprandial fullness) and epigastric pain syndrome (EPS) are increasingly accepted as valid clinical entities, based on new insights into the pathophysiology and the results of clinical trials. Diagnosis is based on the clinical history, and exclusion of peptic ulcer and cancer by endoscopy. Evidence is accumulating FD and gastroesophageal ref lux disease are part of the same disease spectrum in a major subset. The causes of FD remain to be established, but accumulating data suggest infections and possibly food may play an important role in subsets. FD does not equate with no pathology; duodenal eosinophilia is now an accepted association, and Helicobacter pylori infection is considered to be causally linked to dyspepsia although only a minority will respond to eradication. In those with EPS, acid suppression therapy is a first line therapy; consider a H2 blocker even if proton pump inhibitor fails. In PDS, a prokinetic is preferred. Second line therapy includes administration of a tricyclic antidepressant in low doses, or mirtazapine, but not a selective serotonin reuptake inhibitor.

Changing prevalence of Helicobacter pylori infection and peptic ulcer among dyspeptic Sardinian patients

Over the past 50 years, the prevalence of Helicobacter pylori infection has fallen as standards of living improved. The changes in the prevalence of infection and its manifestations (peptic ulcer disease and gastric mucosal lesions) were investigated in a large cohort of Sardinians undergoing upper endoscopy for dyspepsia. A retrospective observational study was conducted involving patients undergoing endoscopy for dyspepsia from 1995 to 2013. H. pylori status was assessed by histology plus the rapid urease test or 13C-UBT. Gastric mucosal lesions were evaluated histologically. Data including non-steroidal anti-inflammatory drugs (NSAIDs) use and the presence of peptic ulcers were collected. The prevalence of H. pylori was calculated for each quartile and for each birth cohort from 1910 to 2000. 11,202 records were retrieved for the analysis (62.9% women). The overall prevalence of H. pylori infection was 43.8% (M: 46.6% vs. F: 42.0%; P = 0.0001). A dramatic decrease in the prevalence of infection occurred over the 19-year observation period. The birth cohort effect was evident in each category (quartile) reflecting the continuous decline in H. pylori acquisition. Over time, the prevalence of peptic ulcers also declined, resulting in an increase in the proportion of H. pylori negative/NSAID positive and H. pylori negative/NSAID negative peptic ulcers. The prevalence of gastric mucosal changes also declined despite aging. The decline in H. pylori prevalence over time likely reflects the improvement in socioeconomic conditions in Sardinia such that H. pylori infection and its clinical outcomes including peptic ulcer are becoming less frequent even among dyspeptic patients.