Inverse correlation between Helicobacter pylori colonization and obesity in a cohort of inner city children

Obesity, abdominal obesity, metabolic obesity phenotypes, and Helicobacter pylori infection: results from NHANES 1999-2000

BACKGROUND

Recent studies on the association between Helicobacter pylori (H. pylori) infection and obesity have reported conflicting results. Therefore, the purpose of our study was to investigate the association of obesity, abdominal obesity, and metabolic obesity phenotypes with H. pylori infection.

METHODS

A cross-sectional study of 1568 participants aged 20 to 85 was conducted using the National Health and Nutrition Examination Survey (NHANES) cycle 1999-2000. Logistic regression models were employed to evaluate the association of general obesity as defined by body mass index (BMI), abdominal obesity as defined by waist circumference (WC) and waist-height ratio (WHtR), and metabolic obesity phenotypes with H. pylori seropositivity. Subgroup analyses stratified by age were conducted to explore age-specific differences in this association.

RESULTS

After grouping individuals according to their WHtR, the prevalence rate of WHtR ≥ 0.5 in H. pylori-seropositive participants was significantly higher than that in H. pylori-seronegative participants (79.75 vs. 68.39, P < 0.001). The prevalence of H. pylori seropositivity in non-abdominal obesity and abdominal obesity defined by WHtR was 24.97% and 31.80%, respectively (P < 0.001). In the subgroup analysis, the adjusted association between abdominal obesity, as defined by the WHtR, and H. pylori seropositivity was significant in subjects aged < 50 years (OR = 2.23; 95% CI, 1.24-4.01; P = 0.01) but not in subjects aged ≥ 50 years (OR = 0.84; 95% CI, 0.35-1.99; P = 0.66). Subjects older than 50 years old had an OR (95% CI) for metabolically healthy obesity of 0.04 (0.01-0.35) compared with the control group. H. pylori seropositivity was consistently not associated with obesity as defined by BMI.

CONCLUSIONS

Abdominal obesity, as defined by the WHtR, was associated with H. pylori infection in subjects aged ≤ 50 years.

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

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

Association between Helicobacter pylori antibody-positive status and extragastric diseases in Japanese junior high school students

BACKGROUND

Helicobacter pylori (H. pylori) infection causes various extragastric diseases. Its transmission route has still not been clarified. However, no large-scale studies have examined the extragastric diseases caused by H. pylori in adolescents. This study aimed to examine the association of H. pylori infection with anemia, serum cholesterol levels, physique, and birth delivery method (vaginal or cesarean) in a large number of Japanese adolescents.

METHODS

From 2016 to 2018, we screened 2,399 adolescents (aged 13-15 years) in their second and third years of junior high school using an enzyme-linked immunosorbent assay-based antibody test. Red blood cells, hemoglobin, hematocrit, total cholesterol, high-density lipoprotein (HDL) cholesterol, and serum antibody levels were measured.

RESULTS

Hemoglobin and hematocrit levels were significantly lower in the H. pylori antibody-positive group than in the H. pylori antibody-negative group in both sexes (boys: P = 0.0004 and 0.0022; girls: P = 0.0019 and 0.0005, respectively). Total cholesterol and non-HDL cholesterol levels were significantly higher in the H. pylori-positive group than in the H. pylori-negative group among boys (P = 0.0370 and 0.0293 respectively). There was no significant difference in body mass index percentile and birth delivery method between the H. pylori-positive and H. pylori-negative groups in both boys and girls.

CONCLUSIONS

Among Japanese junior high school students, H. pylori antibody-positive status was associated with anemia in both sexes while total cholesterol and non-HDL cholesterol levels were associated among boys. There was no association between H. pylori antibody status, body mass index percentile, and birth-delivery method.

Effect of Helicobacter Pylori Infection on Nutritional Status in Polish Teenagers

Purpose

Data on an association between Helicobacter pylori (H. pylori) and nutritional status in children are conflicting. We designed a large-sampled prospective community-based study to examine the differences in average body indices among Polish teenagers depending on their H. pylori status.

Methods

From September 2008 to June 2015, 3067 second junior high school students aged between 13 and 17 years (mean age: 14.5) from 11 randomly selected schools from Grudziadz, Poland, were recruited. For the cohort, ¹³C urea breath test for current H. pylori infection was performed and data on anthropometric measurements and sociodemographic characteristics were collected. Z scores of height for age (HAZ), weight for age (WAZ), and BMI for age (BMIZ) were calculated.

Results

The H. pylori colonisation rate was 23.6% with no gender difference. Compared to noninfected, H. pylori infected had significantly lower mean WAZ (0.0085) and BMIZ scores (p = 0.0246). Univariate linear regression models showed that living in the old town district and consumption of tap water were negative predictors of HAZ, living in the old town district, using collective catering facilities, and H. pylori infection were negative predictors of WAZ, and using collective catering facilities and H. pylori infection were negative predictors of BMIZ. In the multiple regression analyses, living in the old town district (p = 0.0039), using collective catering facilities (p < 0.0001), and H. pylori infection (p = 0.0269) were confirmed to be independently associated with lower WAZ, whereas using collective catering facilities (p < 0.0001) and H. pylori infection (p = 0.0265) were confirmed to be independently associated also with lower BMIZ.

Conclusion

Our finding confirms the evidence on independent negative influence of H. pylori infection on nutritional status in Polish teenagers.

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.

Lack of association between Helicobacter pylori infection and childhood overweight/obesity

BACKGROUND

The reduction in the prevalence of Helicobacter pylori (H. pylori) infection in developed countries coincides with the increasing incidence of obesity and might be a contributing factor to the obesity epidemic. We aimed to evaluate the association between H. pylori infection and childhood overweight/ obesity in Israeli children.

MATERIAL AND METHODS

Patients diagnosed with H. pylori infection by endoscopy, histology, and a positive culture, between January 2013 and August 2018, were identified and compared with H. pylori-negative children, of the same age and gender, undergoing endoscopy for the same indications during the same time period. Data collected included the following: age, gender, height, weight, BMI, BMI percentile, and the indication for endoscopy. Patients with missing anthropometric data or having a disease affecting growth were excluded.

RESULTS

We included 146 H. pylori-positive children and 146 age- and gender-matched H. pylori-negative patients. 63.7% (186/292) were female, mean age 13.1 ± 3.7. Overweight (BMI between the 85th-95th percentile) and obesity (BMI > 95th percentile) were present in 56/292 (19.2%). Among the H. pylori-positive children, 11.6% were overweight, 7.5% obese, among the H. pylori-negative children, 10.3% were overweight, 8.9% obese, demonstrating no differences between the groups. The main indication for endoscopy was abdominal/ epigastric pain in 79.8% (233/292). The percent of children with a BMI ≥ 85% did not differ by gender age or the indication for endoscopy.

CONCLUSIONS

No association between H. pylori infection and childhood overweight/ obesity was demonstrated. This is in contrasts with previous pediatric studies demonstrating an inverse correlation.

Persistent infection of Helicobacter pylori affects weight loss in obese population compared with persistent negative: A case-control study based on healthy Chinese

BACKGROUND

The relationship between Helicobacter pylori (H pylori) and body mass index (BMI) is still inconclusive. Not only the high rate of H pylori infection but also the increasing higher BMI levels are endangering Chinese today.

METHODS

The aim of this research was to evaluate the association between different situations of H pylori infection and BMI values or levels in Chinese healthy population. A total of 39 091 individuals aged from 18 years to 80 years, performed healthy examination including a ¹³ C/¹⁴ C urease breath test (¹³ C/¹⁴ C-UBT), were included. Among them, 30 224 individuals only had one time of health examination, and 8867 had two or more times. A case-cohort data of 8752 with an interval time more than 6 months, collected by the first and the last time, were established from the latter. BMI groups are classified according to the China recommendation: low weight (<18.5 kg/m² ), normal weight (18.5 ~ 23.9 kg/m² ), overweight (24.0 ~ 27.9 kg/m² ), and obesity (≥28.0 kg/m² ).

RESULTS

The rate of H pylori infection among low weight, normal weight, overweight, and obesity was 43.2%, 44.7%, 46.4%, and 48.0%, respectively (P = .000). H pylori infection increased the risk of higher level of BMI (OR = 1.077, 95% confidence interval = 1.036-1.119, χ²  = 14.048, P = .000) with adjustments for sex and age. In the case-control study, the rate of persistent negative, persistent infection, new infection, and eradicated infection was 39.5%, 25.8%, 15.8%, and 18.9%, respectively, with a median interval time of 13 months. The mean obesity BMI descend values in the persistent negative subgroup were lower than those in the persistent infection subgroup (-0.21 ± 1.19 kg/m² vs -0.003 ± 1.01 kg/m² , P = .021). But the change of BMI classifications had no difference between the subgroups of H pylori infection in different BMI levels.

CONCLUSIONS

H pylori infection was positively correlated with higher BMI levels. And H pylori persistent infection had a negative effect on the fall of BMI values in Chinese obese population.

Helicobacter pylori in relation to asthma and allergy modified by abdominal obesity: The HUNT study in Norway

Objective

It is unknown whether the decreasing prevalence of H. pylori infections is associated with the increase in obesity and asthma and allergy. In this study, we assessed if obesity plays an intermediate role between H. pylori infections and allergy.

Design

A population-based, nested case-control study of 10,005 participants within the second Nord-Trøndelag Health Study (HUNT2), Norway, was performed in 1995-1997. The presence of H. pylori was tested by an enzyme immunoassay Pyloriset EIA-IgG, and weight, height, and waist circumference were measured. Body mass index (BMI) and waist circumference were used as measures of general and abdominal obesity, respectively. Self-reported asthma and allergic diseases were collected through questionnaires. The odds ratios of H. pylori relative to asthma and allergic diseases were estimated by logistic regression models stratified by waist circumference categories.

Results

H. pylori infection was present in 31%, ever asthma was reported in 10.4% and allergic rhinitis in 16.2%. The mean BMI was 26.4 ​kg/m² and the mean waist circumference was 86.6 ​cm. H. pylori infection was neither associated with asthma nor allergic diseases. However, when stratified by waist circumference, H. pylori infection was associated with 30-40% reduced odds of asthma and 25% reduced odds of allergic diseases in individuals with abdominal obesity (waist circumference ≥86 ​cm in women and ≥96 ​cm in men).

Conclusion

H. pylori infection is associated with reduced risk of asthma and allergy in individuals with abdominal obesity, suggesting a possible causal pathway from reduced H. pylori infections through obesity to increased risk of asthma and allergy.

Helicobacter pylori infection is positively associated with an increased BMI, irrespective of socioeconomic status and other confounders: a cohort study

BACKGROUND

Data on the association of Helicobacter pylori infection and BMI are conflicting. The fact that both H. pylori infection and BMI are associated with low socioeconomic status (SES) makes this relationship difficult to characterize.

MATERIALS AND METHODS

We aimed to evaluate the association between BMI and H. pylori infection after adjusting for multiple covariates. We analyzed a cohort of 235 107 individuals aged 18 years or older, who performed a C urease breath test (C-UBT), from 2007 to 2014. Data on BMI, age, sex, SES, ethnicity, and medications were extracted from a nationwide population-based database. BMIs were classified according to the WHO recommendations: underweight (<18.5 kg/m), normal weight (18.5-24.9 kg/m), overweight (25-29.9 kg/m), obese class I (30-34.9 kg/m), and obese class II or more (>35 kg/m).

STUDY RESULTS

The positivity rate for H. pylori among underweight, normal weight, overweight, and obese class I and class II or more was 55.6, 58.5, 63.0, 64.5, and 65.5%, respectively (P<0.001, Plinear trend 0.007). The association between BMI and H. pylori infection was significant across all SES, sex, ethnicity, and age categories. After adjusting for age, sex, ethnicity, and SES, being overweight and obese class I and class II or more were associated significantly with H. pylori positivity: odds ratio 1.13 [95% confidence interval (CI): 1.11-1.15], 1.14 (95% CI: 1.11-1.17), and 1.15 (95% CI: 1.11-1.19), respectively, P value less than 0.001 for all.

CONCLUSION

Among individuals who were referred to a C-UBT by primary care physician, after adjusting for multiple covariates including SES, we found a positive association between H. pylori infection and an increased BMI.

Helicobacter pylori colonization and obesity - a Mendelian randomization study

Obesity is associated with substantial morbidity, costs, and decreased life expectancy, and continues to rise worldwide. While etiological understanding is needed for prevention, epidemiological studies indicated that colonization with Helicobacter pylori (H. pylori) may affect body mass index (BMI), but with inconsistent results. Here, we examine the relationship between H. pylori colonization and BMI/obesity. Cross-sectional analyses were performed in two independent population-based cohorts of elderly from the Netherlands and Germany (n = 13,044). Genetic risk scores were conducted based on genetic loci associated with either H. pylori colonization or BMI/obesity. We performed a bi-directional Mendelian randomization. Meta-analysis of cross-sectional data revealed no association between anti-H. pylori IgG titer and BMI, nor of H. pylori positivity and BMI. Anti-H. pylori IgG titer was negatively associated with obesity (OR 0.99972; 95% CI 0.99946-0.99997, p = 0.03) and with obesity classes (Beta −6.91 •10⁻⁵; 95% CI −1.38•10⁻⁴, −5.49•10⁻⁷, p = 0.048), but the magnitude of these effects was limited. Mendelian randomization showed no causal relation between H. pylori genetic risk score and BMI/obesity, nor between BMI or obesity genetic risk scores and H. pylori positivity. This study provides no evidence for a clinically relevant association between H. pylori and BMI/obesity.

Body mass index at adolescence and risk of noncardia gastric cancer in a cohort of 1.79 million men and women

BACKGROUND

This study assessed adolescent predictors of noncardia gastric cancer (NCGC) with a focus on the body mass index (BMI) in late adolescence.

METHODS

This study analyzed a cohort of 1,087,358 Israeli Jewish males and 707,212 Israeli Jewish females who underwent a compulsory physical examination between the ages of 16 and 19 years from 1967 to 2002. By linkage to the national cancer registry, participants were followed for NCGC through December 31, 2012. With a median follow-up of 23 years, 515 NCGC cases occurred (379 men and 136 women), and the median age was 47.0 years (interquartile range, 39.3-53.4 years). Multivariate-adjusted Cox regression was used to estimate hazard ratios (HRs) for NCGC according to the US Centers for Disease Control and Prevention BMI percentiles at the baseline (normal weight, 5th to <85th percentile; overweight, 85th to <95th percentile; and obesity, ≥95th percentile) as well as the country of birth, residential socioeconomic status (SES), and education.

RESULTS

In comparison with normal weight, adolescent obesity, but not overweight, was associated in both men and women with the risk of subsequent NCGC (unadjusted HR, 1.95; 95% confidence interval [CI], 1.25-3.06; adjusted HR, 1.78; 95% CI, 1.12-2.83). Immigration from the former Soviet Union (FSU), a low education level, and a low residential SES were also associated with the risk for NCGC with adjusted HRs of 2.67 (95% CI, 1.86-3.83), 1.85 (95% CI, 1.53-2.25), and 1.48 (95% CI, 1.13-1.93), respectively.

CONCLUSIONS

The findings suggest that adolescent obesity, but not overweight, is associated with an increased risk for NCGC. Immigration from the FSU, a low residential SES, and a low education level are also significantly associated with the risk for NCGC. Cancer 2018;124:356-63. © 2017 American Cancer Society.

Gastric microbiota: tracing the culprit

The gastric environment has been long time considered bacteria-free, but the discovery of Helicobacter pylori (H. pylori) in 1982 superseded this conception. Over the last decades new diagnostic methods have been developed, starting with culture-dependent and advancing to culture-independent ones. These modern techniques provide new insight into the composition and influence of this ecosystem on the entire gastrointestinal tract. H. pylori is no longer considered the only microorganism in the stomach, other non-H. pylori microbial species may populate the same environment and exercise their role. Current knowledge suggests possible links of these bacteria with gastroduodenal diseases, such as peptic ulcer and gastric cancer but most of them need further scientific evidence. This review summarizes current information on these complex interrelations between gastric microbial communities and host in health and disease.

Review: Prevalence and dynamics of Helicobacter pylori infection during childhood

INTRODUCTION

Long-term persistent Helicobacter pylori infection has been associated with ulceropeptic disease and gastric cancer. Although H. pylori is predominantly acquired early in life, a clear understanding of infection dynamics during childhood has been obfuscated by the diversity of populations evaluated, study designs, and methods used.

AIM

Update understanding of true prevalence of H. pylori infection during childhood, based on a critical analysis of the literature published in the past 5 years.

METHODS

Comprehensive review and meta-analysis of original studies published from 2011 to 2016.

RESULTS

A MEDLINE^® /PubMed^® search on May 1, 2016, using the terms pylori and children, and subsequent exclusion, based on abstract review using predefined criteria, resulted in 261 citations. An Embase^® search with the same criteria added an additional 8 citations. In healthy children, meta-analysis estimated an overall seroprevalence rate of 33% (95% CI: 27%-38%). Seven healthy cohort studies using noninvasive direct detection methods showed infection prevalence estimates ranging from 20% to 50% in children ≤5 and 38% to 79% in children >5 years. The probability of infection persistence after a first positive sample ranged from 49% to 95%. Model estimates of cross-sectional direct detection studies in asymptomatic children indicated a prevalence of 37% (95% CI: 30%-44%). Seroprevalence, but not direct detection rates increased with age; both decreased with increasing income. The model estimate based on cross-sectional studies in symptomatic children was 39% (95% CI: 35%-43%).

CONCLUSIONS

The prevalence of H. pylori infection varied widely in the studies included here; nevertheless, model estimates by detection type were similar, suggesting that overall, one-third of children worldwide are or have been infected. The few cohort and longitudinal studies available show variability, but most studies, show infection rates over 30%. Rather surprisingly, overall infection prevalence in symptomatic children was only slightly higher, around 40%. Studies including only one positive stool sample should be interpreted with caution as spontaneous clearance can occur.

Inverse Correlation between Helicobacter pylori Colonization and Pediatric Overweight: A Preliminary Study

BACKGROUND

Helicobacter pylori, one of the most common bacterial pathogens in humans, is generally acquired during childhood. The inverse correlation between H. pylori colonization and obesity that was found in adults has not been investigated in depth in children. Our aim was to assess the correlation between overweight and obesity and H. pylori colonization in a pediatric population.

METHODS

H. pylori colonization in 70 symptomatic children was determined after antral biopsies during esophagogastroduodenoscopy. Data on anthropometric measurements, sociodemographic characteristics, and medical history were recorded.

RESULTS

The participants' mean age was 12.41 ± 3.16 years, 58% were females, and 24% were obese or overweight (BMI >85th percentile). The H. pylori colonization rate was 31%. There were no significant differences between the H. pylori-infected and H. pylori-noninfected groups in terms of age, gender, or clinical and sociodemographic characteristics. Nevertheless, the prevalence of overweight and obesity was significantly lower in children with H. pylori colonization compared to children with normal histology (31% in the noninfected group compared to 11% in the infected group, p = 0.04). The mean fat percentage was 24.3 ± 8.8 and 19.4 ± 6.9, respectively (p = 0.02).

CONCLUSIONS

The findings of this prospective study are in agreement with previous studies and demonstrate an inverse relationship between H. pylori colonization and overweight or obesity among symptomatic children. A larger prospective, multiethnic investigation is warranted to more definitively determine the extent of this association.

Helicobacter pylori infection is not associated with failure to thrive: a case control study

Purpose

The long-term impact of Helicobacter pylori infection is complex, and concerns about the need for eradication exist. We conducted this case control study to investigate the association between H. pylori infection and failure to thrive (FTT).

Patients and methods

From January 2009 to December 2011, 53 children with FTT group and matched children with the same sex and age and similar socioeconomic status without FTT (control group) were enrolled. A questionnaire was administered to the parents/guardian, and a ¹³C-urea breath test was performed to detect H. pylori infection.

Results

We found that the total prevalence of H. pylori infection was 29.2% and that there was no association between FTT and H. pylori infection (FTT group: 32%; control group: 26.4%; P=0.67). Short stature was more common in the FTT group and abdominal pain in the control group (FTT group: 37.7%; control group: 11.3%; P=0.003). In a comparison between the H. pylori-positive and -negative groups, abdominal pain (87.1% vs 64%; P=0.032) and the frequency of endoscopy (74.2% vs 32%; P<0.001) were significantly more common in the H. pylori-positive group.

Conclusion

We found that children with H. pylori infection are at an increased risk for abdominal pain and that FTT is not associated with H. pylori infection. The decision for eradication should be evaluated carefully and individualized.

Functional dyspepsia and dyspepsia associated with Helicobacter pylori infection: Do they have different clinical characteristics?

BACKGROUND

Helicobacter pylori causes motor, secretory, and inflammatory gastrointestinal disorders and therefore the term "functional" has been questioned when referring to dyspepsia associated with this bacterium. Patients with dyspepsia and Helicobacter pylori infection could have clinical characteristics that differentiate them a priori from those with true functional dyspepsia.

AIMS

To determine whether there are clinical differences between patients with functional dyspepsia and Helicobacter pylori-associated dyspepsia that enable their a priori identification and to know the prevalence of Helicobacter pylori infection in patients with functional dyspepsia.

PATIENTS AND METHODS

A total of 578 patients with dyspepsia with no significant lesions detectable through endoscopy were divided into 2 groups according to the presence of Helicobacter pylori. The clinical characteristics, medical history, comorbidities, and use of health resources were compared between the two groups. A sub-analysis pairing the groups by age and sex in a 1:1 ratio was carried out to reduce bias.

RESULTS

A total of 336 patients infected with Helicobacter pylori were compared with 242 non-infected patients. The prevalence of infection in the patients with dyspeptic symptoms and no endoscopically detectable lesions was 58%. The initial analysis showed that the cases with dyspepsia and Helicobacter pylori infection were more frequently associated with overweight, obesity, high blood pressure, diabetes mellitus, and metabolic syndrome, but the paired analysis nullified all these differences.

CONCLUSIONS

The patients with dyspepsia infected with Helicobacter pylori had similar clinical characteristics to the non-infected patients and could not be differentiated a priori. The prevalence of Helicobacter pylori infection in patients with functional dyspepsia was 58% and increased with age.

Systems-wide analyses of mucosal immune responses to Helicobacter pylori at the interface between pathogenicity and symbiosis

Helicobacter pylori is the dominant member of the gastric microbiota in over half of the human population of which 5-15% develop gastritis or gastric malignancies. Immune responses to H. pylori are characterized by mixed T helper cell, cytotoxic T cell and NK cell responses. The presence of Tregs is essential for the control of gastritis and together with regulatory CX3CR1+ mononuclear phagocytes and immune-evasion strategies they enable life-long persistence of H. pylori. This H. pylori-induced regulatory environment might contribute to its cross-protective effect in inflammatory bowel disease and obesity. Here we review host-microbe interactions, the development of pro- and anti-inflammatory immune responses and how the latter contribute to H. pylori's role as beneficial member of the gut microbiota. Furthermore, we present the integration of existing and new data into a computational/mathematical model and its use for the investigation of immunological mechanisms underlying initiation, progression and outcomes of H. pylori infection.

Are probiotics useful in Helicobacter pylori eradication?

Helicobacter pylori (H. pylori) is considered an etiologic factor for the development of peptic ulcer disease, gastric adenocarcinoma, and MALT lymphoma. Therapeutic schemes to eradicate the bacteria are based on double antibiotic therapy and proton pump inhibitor. Despite many therapeutic improvements in H. pylori eradication treatment, it is still associated with high infection rate also in developed countries. Bacterial resistance and adverse events occurrence are among most frequent causes for anti- H. pylori treatment failure. Several studies have reported that certain probiotic strains can exhibit inhibitory activity against H. pylori bacteria. In addition, some probiotic strains can reduce the occurrence of side effects due to antibiotic therapy and consequently increase the H. pylori eradication rate. The results of the prospective double-blind placebo-controlled studies suggest that specific probiotics, such as S. boulardii and L. johnsonni La1 probably can diminish the bacterial load, but not completely eradicate the H. pylori bacteria. Furthermore, it seems that supplementation with S. boulardii is a useful concomitant therapy in the standard H. pylori eradication treatment protocol and most probably increases eradication rate. L. reuteri is equally effective, but more positive studies are needed. Finally, probiotic strains, such as S. boulardii, L. reuteri and L. GG, decrease gastrointestinal antibiotic associated adverse effects.

Helicobacter pylori Infection in Pediatrics

This review includes the main pediatric studies published from April 2014 to March 2015. The host response of Treg cells with increases in FOXP3 and TGF-β1 combined with a reduction in IFN-γ by Teff cells may contribute to Helicobacter pylori susceptibility in children. Genotypic variability in H. pylori strains influences the clinical manifestation of the infection. Helicobacter pylori infection is associated with variables indicative of a crowded environment and poor living conditions, while breast-feeding has a protective effect. Intrafamilial infection, especially from mother to children and from sibling to sibling, is the dominant transmission route. Studies showed conflicting results regarding the association between H. pylori infection and iron deficiency anemia. One study suggests that H. pylori eradication plays a role in the management of chronic immune thrombocytopenic purpura in H. pylori-infected children and adolescents. The prevalence of H. pylori was higher in chronic urticaria patients than in controls and, following H. pylori eradication, urticarial symptoms disappeared. An inverse relationship between H. pylori infection and allergic disease was reported. Antibiotic resistance and insufficient compliance to treatment limit the efficacy of eradication therapy. Sequential therapy had no advantage over standard triple therapy. In countries where H. pylori infection is prevalent, studies focusing on virulence factors and antibiotic susceptibility may provide anticipation of the prognosis and may be helpful to reduce morbidity and mortality.