Quantifying gastric Helicobacter pylori infection: a comparison of quantitative culture, urease breath testing, and histology

Impact of a Fermented High-Fiber Rye Diet on Helicobacter pylori and Cardio-Metabolic Risk Factors: A Randomized Controlled Trial Among Helicobacter pylori-Positive Chinese Adults

Background: High dietary fiber intake has been associated with reduced risk of Helicobacter pylori infection and co-morbidities such as gastric cancer but also with reduced risk of cardiovascular disease. It has been suggested that fermented rye could affect Helicobacter pylori bacterial load and that high- fiber rye may be superior to wheat for improvement of several cardiometabolic risk factors, but few long-term interventions with high fiber rye foods have been conducted. Objective: To examine the effect of high-fiber wholegrain rye foods with added fermented rye bran vs. refined wheat on Helicobacter pylori infection and cardiometabolic risk markers in a Chinese population with a low habitual consumption of high fiber cereal foods. Design: A parallel dietary intervention was set up and 182 normal- or overweight men and women were randomized to consume wholegrain rye products containing fermented rye bran (FRB) or refined wheat (RW) for 12 weeks. Anthropometric measurements, fasting blood sample collection and ¹³C-urea breath test (¹³C-UBT) were performed at baseline and after 6 and 12 weeks of intervention as well as 12 weeks after the end of the intervention. Results: No difference between diets on Helicobacter pylori bacterial load measured by ¹³C-UBT breath test or in virulence factors of Helicobacter pylori in blood samples were found. Low density lipoprotein cholesterol (LDL-C) and high sensitivity C-reactive protein (hs-CRP) were significantly lower in the FRB group, compared to the RW group after 12 weeks of intervention. The intervention diets did not affect markers of glucose metabolism or insulin sensitivity. Conclusions: While the results of the present study did not support any effect of FRB on Helicobacter pylori bacterial load, beneficial effects on LDL-C and hs-CRP were clearly shown. This suggest that consumption of high fiber rye foods instead of refined wheat could be one strategy for primary prevention of cardiovascular disease. Clinical Trial Registration: The trial was registered at www.clinicaltrials.gov, Identifier: NCT03103386.

Where to Biopsy to Detect Helicobacter pylori and How Many Biopsies Are Needed to Detect Antibiotic Resistance in a Human Stomach

This study aims to determine the gastric distribution, density, and diversity of Helicobacter pylori infection. Subtotal resection of the stomachs of three H. pylori-infected and asymptomatic obese patients were collected after a sleeve gastrectomy. Distribution and density of H. pylori were determined using culture and RT-PCR on multiple gastric sites (88, 176, and 101 biopsies per patient). Diversity of H. pylori strains was studied using antibiotic susceptibility testing, random amplified polymorphism DNA (RAPD) typing and cagA gene detection on single-colony isolates (44, 96, and 49 isolates per patient). H. pylori was detected in nearly all analyzed sites (354/365 biopsies, 97%). Antral density was higher in one patient only. The three stomachs were almost exclusively infected by an antibiotic-susceptible strain. One clarithromycin-resistant isolate in one biopsy was detected in two stomachs (1/44 and 1/49 isolates), while in the third one, eight (8/96 isolates) metronidazole-resistant isolates were detected. DNA typing showed infection with cagA-negative strains for one patient, cagA-positive strains for a second patient and the third patient was infected with two different strains of distinct cagA genotypes. Infection with H. pylori is shown to spread to the whole surface of the stomach, but a possibility of minor sub-population of antibiotic-resistant clones, undetectable in routine practice.

Correlation between Quantitative 13C-Urea Breath Test and Helicobacter pylori Treatment Success in a Population-Based Cohort

Background

There are continual efforts to identify factors which influence the success of first-line therapy for Helicobacter pylori (H. pylori) infection. The ¹³C-urea breath test result (C13-UBT) utilizes H. pylori urease activity and is a highly accurate diagnostic assay. We aimed to determine whether the magnitude of C13-UBT result is related to treatment success.

Methods

Adult patients who underwent a first-time ¹³C-urea breath test between January 2010 and January 2016 were included. In order to isolate a naïve test-and-treat population who were unlikely to have undergone an initial endoscopy-based H. pylori test, we excluded patients > 45 years and those with a previous C13-UBT. Data were extracted from the Clalit Health Services laboratory database.

Results

A total of 94,590 subjects (36.1% male, age 28.5 ± 6.0 years) who underwent a first-time C13-UBT during the study period were included. C13-UBT was positive in 48,509 (51.3%) subjects. A confirmatory posttreatment C13-UBT was performed in 18,375 (37.8%), and eradication was successful in 12,018 (65.4%). The mean C13-UBT recording was 20.6 ± 16.2 DOB in subjects with successful eradication and 19.5 ± 13.1 DOB in subjects with treatment failure (OR, 1.01; 95% CI 1.00-1.01, p < 0.01). Among patients in the upper quintile of C13-UBT measurement, eradication was achieved in 67.6%, compared to 62.6% in the lower quintile (OR, 1.22; 95% CI 1.11-1.35, p < 0.01). Subjects in the top 1 percentile (C13-UBT ≥ 70 DOB) achieved eradication in 75.0%, compared to 65.3% among subjects with C13-UBT < 70 DOB (OR, 1.59; 95% CI 1.05-2.41, p < 0.01).

Conclusions

The superiority in H. pylori eradication observed in subjects with a higher C13-UBT DOB is small but significant. Further studies should examine the physiological and microbiological basis for this finding.

Non-invasive diagnostic tests for Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H pylori) infection has been implicated in a number of malignancies and non-malignant conditions including peptic ulcers, non-ulcer dyspepsia, recurrent peptic ulcer bleeding, unexplained iron deficiency anaemia, idiopathic thrombocytopaenia purpura, and colorectal adenomas. The confirmatory diagnosis of H pylori is by endoscopic biopsy, followed by histopathological examination using haemotoxylin and eosin (H & E) stain or special stains such as Giemsa stain and Warthin-Starry stain. Special stains are more accurate than H & E stain. There is significant uncertainty about the diagnostic accuracy of non-invasive tests for diagnosis of H pylori.

OBJECTIVES

To compare the diagnostic accuracy of urea breath test, serology, and stool antigen test, used alone or in combination, for diagnosis of H pylori infection in symptomatic and asymptomatic people, so that eradication therapy for H pylori can be started.

SEARCH METHODS

We searched MEDLINE, Embase, the Science Citation Index and the National Institute for Health Research Health Technology Assessment Database on 4 March 2016. We screened references in the included studies to identify additional studies. We also conducted citation searches of relevant studies, most recently on 4 December 2016. We did not restrict studies by language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We included diagnostic accuracy studies that evaluated at least one of the index tests (urea breath test using isotopes such as 13C or 14C, serology and stool antigen test) against the reference standard (histopathological examination using H & E stain, special stains or immunohistochemical stain) in people suspected of having H pylori infection.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the references to identify relevant studies and independently extracted data. We assessed the methodological quality of studies using the QUADAS-2 tool. We performed meta-analysis by using the hierarchical summary receiver operating characteristic (HSROC) model to estimate and compare SROC curves. Where appropriate, we used bivariate or univariate logistic regression models to estimate summary sensitivities and specificities.

MAIN RESULTS

We included 101 studies involving 11,003 participants, of which 5839 participants (53.1%) had H pylori infection. The prevalence of H pylori infection in the studies ranged from 15.2% to 94.7%, with a median prevalence of 53.7% (interquartile range 42.0% to 66.5%). Most of the studies (57%) included participants with dyspepsia and 53 studies excluded participants who recently had proton pump inhibitors or antibiotics.There was at least an unclear risk of bias or unclear applicability concern for each study.Of the 101 studies, 15 compared the accuracy of two index tests and two studies compared the accuracy of three index tests. Thirty-four studies (4242 participants) evaluated serology; 29 studies (2988 participants) evaluated stool antigen test; 34 studies (3139 participants) evaluated urea breath test-13C; 21 studies (1810 participants) evaluated urea breath test-14C; and two studies (127 participants) evaluated urea breath test but did not report the isotope used. The thresholds used to define test positivity and the staining techniques used for histopathological examination (reference standard) varied between studies. Due to sparse data for each threshold reported, it was not possible to identify the best threshold for each test.Using data from 99 studies in an indirect test comparison, there was statistical evidence of a difference in diagnostic accuracy between urea breath test-13C, urea breath test-14C, serology and stool antigen test (P = 0.024). The diagnostic odds ratios for urea breath test-13C, urea breath test-14C, serology, and stool antigen test were 153 (95% confidence interval (CI) 73.7 to 316), 105 (95% CI 74.0 to 150), 47.4 (95% CI 25.5 to 88.1) and 45.1 (95% CI 24.2 to 84.1). The sensitivity (95% CI) estimated at a fixed specificity of 0.90 (median from studies across the four tests), was 0.94 (95% CI 0.89 to 0.97) for urea breath test-13C, 0.92 (95% CI 0.89 to 0.94) for urea breath test-14C, 0.84 (95% CI 0.74 to 0.91) for serology, and 0.83 (95% CI 0.73 to 0.90) for stool antigen test. This implies that on average, given a specificity of 0.90 and prevalence of 53.7% (median specificity and prevalence in the studies), out of 1000 people tested for H pylori infection, there will be 46 false positives (people without H pylori infection who will be diagnosed as having H pylori infection). In this hypothetical cohort, urea breath test-13C, urea breath test-14C, serology, and stool antigen test will give 30 (95% CI 15 to 58), 42 (95% CI 30 to 58), 86 (95% CI 50 to 140), and 89 (95% CI 52 to 146) false negatives respectively (people with H pylori infection for whom the diagnosis of H pylori will be missed).Direct comparisons were based on few head-to-head studies. The ratios of diagnostic odds ratios (DORs) were 0.68 (95% CI 0.12 to 3.70; P = 0.56) for urea breath test-13C versus serology (seven studies), and 0.88 (95% CI 0.14 to 5.56; P = 0.84) for urea breath test-13C versus stool antigen test (seven studies). The 95% CIs of these estimates overlap with those of the ratios of DORs from the indirect comparison. Data were limited or unavailable for meta-analysis of other direct comparisons.

AUTHORS' CONCLUSIONS

In people without a history of gastrectomy and those who have not recently had antibiotics or proton ,pump inhibitors, urea breath tests had high diagnostic accuracy while serology and stool antigen tests were less accurate for diagnosis of Helicobacter pylori infection.This is based on an indirect test comparison (with potential for bias due to confounding), as evidence from direct comparisons was limited or unavailable. The thresholds used for these tests were highly variable and we were unable to identify specific thresholds that might be useful in clinical practice.We need further comparative studies of high methodological quality to obtain more reliable evidence of relative accuracy between the tests. Such studies should be conducted prospectively in a representative spectrum of participants and clearly reported to ensure low risk of bias. Most importantly, studies should prespecify and clearly report thresholds used, and should avoid inappropriate exclusions.

Helicobacter pylori chronic gastritis updated Sydney grading in relation to endoscopic findings and H. pylori IgG antibody: diagnostic methods

Helicobacter pylori (Hp) inhabits the stomach of > 50% of humans and has been established as a major etiological factor in the pathogenesis of chronic gastritis, gastric atrophy, peptic ulcer disease, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. The aim of this study was to provide unequivocal information about Hp-associated gastritis grading according to the Sydney grading system and to compare the histopathological features with the endoscopic findings and anti-Hp immunoglobulin (Ig)G serological status. This analytical study was conducted on 157 patients with dyspeptic gastritis. All patients underwent esophagogastroduodenoscopy, and antrum and corpus biopsies were taken. Blood samples were obtained from all participants. Different stains were performed on formalin-fixed, paraffin-embedded tissue blocks that included hematoxylin and eosin and Giemsa stain for histopathological interpretation. The endoscopic findings of gastritis were observed in 120 patients and most of them showed hyperemia (80 patients), whereas seven patients had normal appearing gastric mucosa. Histologically variable numbers of mononuclear inflammatory cellular infiltrates were seen in 150 cases (95.5%). Most of them showed Grade 1 gastritis (80 patients), whereas Grades 2 and 3 were found in 43 and 27 biopsies, respectively. Hp colonization was observed in most of the examined biopsies (93.7%). Hp-IgG seropositivity was found in 80.9% of cases and 19.1% were seronegative. The relationship between endoscopic and histological findings was significant (p < 0.001).

Fiber-enhanced Raman multigas spectroscopy: a versatile tool for environmental gas sensing and breath analysis

Versatile multigas analysis bears high potential for environmental sensing of climate relevant gases and noninvasive early stage diagnosis of disease states in human breath. In this contribution, a fiber-enhanced Raman spectroscopic (FERS) analysis of a suite of climate relevant atmospheric gases is presented, which allowed for reliable quantification of CH4, CO2, and N2O alongside N2 and O2 with just one single measurement. A highly improved analytical sensitivity was achieved, down to a sub-parts per million limit of detection with a high dynamic range of 6 orders of magnitude and within a second measurement time. The high potential of FERS for the detection of disease markers was demonstrated with the analysis of 27 nL of exhaled human breath. The natural isotopes (13)CO2 and (14)N(15)N were quantified at low levels, simultaneously with the major breath components N2, O2, and (12)CO2. The natural abundances of (13)CO2 and (14)N(15)N were experimentally quantified in very good agreement to theoretical values. A fiber adapter assembly and gas filling setup was designed for rapid and automated analysis of multigas compositions and their fluctuations within seconds and without the need for optical readjustment of the sensor arrangement. On the basis of the abilities of such miniaturized FERS system, we expect high potential for the diagnosis of clinically administered (13)C-labeled CO2 in human breath and also foresee high impact for disease detection via biologically vital nitrogen compounds.

Helicobacter pylori eradication: Sequential therapy and Lactobacillus reuteri supplementation

AIM: To evaluate the role of sequential therapy and Lactobacillus reuteri (L. reuteri) supplementation, in the eradication treatment of Helicobacter pylori (H. pylori).

METHODS: H. pylori infection was diagnosed in 90 adult dyspeptic patients. Patients were excluded if previously treated for H. pylori infection or if they were taking a proton pump inhibitor (PPI), H2-receptor antagonist or antibiotics. Patients were assigned to receive one of the following therapies: (1) 7-d triple therapy (PPI plus clarithromycin and amoxicillin or metronidazole) plus L. reuteri supplementation during antibiotic treatment; (2) 7-d triple therapy plus L. reuteri supplementation after antibiotic treatment; (3) sequential regimen (5-d PPI plus amoxicillin therapy followed by a 5-d PPI, clarithromycin and tinidazole) plus L. reuteri supplementation during antibiotic treatment; and (4) sequential regimen plus L. reuteri supplementation after antibiotic treatment. Successful eradication therapy was defined as a negative urea breath test at least 4 wk following treatment.

RESULTS: Ninety adult dyspeptic patients were enrolled, and 83 (30 male, 53 female; mean age 57 ± 13 years) completed the study. Nineteen patients were administered a 7-d triple treatment: 11 with L. reuteri supplementation during and 8 after therapy. Sixty-four patients were administered a sequential regimen: 32 with L. reuteri supplementation during and 32 after therapy. The eradication rate was significantly higher in the sequential group compared with the 7-d triple regimen (88% vs 63%, P = 0.01). No difference was found between two types of PPI. No difference in eradication rates was observed between patients submitted to L. reuteri supplementation during or after antibiotic treatment. Compliance with therapy was excellent in all patients. No difference in adverse effects was observed between the different antibiotic treatments and between patients submitted to L. reuteri supplementation during and after antibiotic treatment. There was a low incidence of adverse effects in all groups of patients with sequential therapy, probably due to the presence of the L. reuteri supplementation.

CONCLUSION: The sequential treatment regimen achieved a significantly higher eradication rate of H. pylori compared with standard 7-d regimen. L. reuteri supplementation could reduce the frequency and the intensity of antibiotic-associated side-effects.

Bacterial load and degree of gastric mucosal inflammation in Helicobacter pylori infection

Helicobacter pylori induces an inflammatory immune response in the gastric mucosa. The degree of gastric mucosal inflammation and its topographic distribution are key factors in the diversity of H. pylori-related complications. Here we summarize substantial evidence reported in the literature concerning the impact of H. pylori density on gastric inflammation, the development of severe complications, and its relation to H. pylori suppression therapy. Most studies demonstrate a significant correlation between H. pylori density and the grade of acute and chronic inflammation, taking into account the limitations of each method for density assessment. Overall, high bacterial loads are associated with increased acute mucosal damage and long-term changes in the gastric mucosa. The influence of H. pylori density reduction on the improvement of gastric mucosal changes was observed in studies using 'clearance' therapies. Mucosal agents provoke a significant, but not persistent, reduction in gastritis activity. Treatments suppressing the density and virulence of H. pylori could become strategies to prevent H. pylori-associated disease in the future.

Age and gender differences in urea breath test results

BACKGROUND

(13) C urea breath test (UBT) results, used for the diagnosis of Helicobacter pylori infection, fluctuate in different age groups. We characterized both the age- and gender-based trends of UBT results, from early childhood through late adulthood.

METHODS

A national H. pylori referral laboratory was screened for all positive UBTs during 2007-2008, determined as a delta over baseline (DOB) ≥ 3·5. Data were analysed with respect to both age and gender.

RESULTS

In the studied period, 61,060 UBTs were performed and 24,237 were positive. After excluding multiple testing for an individual, a total of 21,767 positive results were analysed. The male/female ratio for positive UBTs was 1 : 1·77. DOB results decreased as age increased from a maximum of 38·6 ± 21 at age 3-5 years to 21·1 ± 12 at age 19-30 in females (P < 0·001) and from 30·0 ± 16 at age 6-10 years to 14·7 ± 8 at age 19-30 years in males (P < 0·0001). At this point, the values reached a nadir for both genders. In patients older than 60 years, old test results increased moderately (P < 0·003). In all age groups, except 6-10 years old, females had significantly higher UBT results than males.

CONCLUSIONS

The decrease in mean UBT values already occurs during the first decade of life, and results increase following the sixth decade. Females have significantly higher results than males even in early childhood and throughout old age.

Helicobacter pylori: diagnosis and treatment

PURPOSE OF REVIEW

Multiple diagnostic methods and treatment strategies have been developed to detect and treat the Helicobacter pylori infection. Many of them have stood the test of time; others lost their value with the introduction of new test and treatment modalities. This review focuses on the current diagnostic methods and their clinical implications, as well as on established and novel treatment strategies.

RECENT FINDINGS

The increasing antimicrobial resistance has resulted in a decline of the success rate of recommended eradication regimens. The current guidelines recommend as first-line treatment clarithromycin, amoxicillin or metronidazole, and proton pump inhibitor twice daily, but recent studies have demonstrated an increasing eradication failure with these regimens. Several treatment modifications have been adopted regarding duration and combination of substances.

SUMMARY

The currently recommended first-line treatments are effective and well tolerated. In areas with high antimicrobial resistance rates, new antibiotic combinations and modifications in the sequence of drug administration are proposed as alternative treatment options to standard triple therapy. Future treatment strategies have to focus on regional antimicrobial resistance adopted treatment selection and the development of new antibiotics.

Diagnosis of Helicobacter pylori

Although there are attempts to perform Helicobacter pylori diagnosis directly in vivo using magnification endoscopy, most articles on diagnosis this year concerned non-invasive tests and molecular methods. For urea breath tests, there are attempts to have a quicker and cheaper test and to evaluate its role in cases of premalignant lesions. For stool antigens tests, evaluation of kits using monoclonal antibodies was carried out. Molecular tests have been applied for typing and detection of resistant mutants.