Eradication of Helicobacter pylori increases childhood growth and serum acylated ghrelin levels

The causal effect of Helicobacter pylori infection on coronary heart disease is mediated by the body mass index: a Mendelian randomization study

The association between Helicobacter pylori (H. pylori) infection and coronary heart disease (CHD) remains controversial, with an unclear causal link. This study employed bidirectional Mendelian randomization (MR) method, using H. pylori infection as the exposure, to investigate its causal relationship with CHD diagnosis, prognosis, and potential pathogenesis. H. pylori infection exhibited a causal association with body mass index (BMI) (β = 0.022; 95% CI 0.008-0.036; p = 0.001). Conversely, there was no discernible connection between H. pylori infection and the diagnosis of CHD (OR = 0.991; 95% CI 0.904-1.078; p = 0.842; IEU database; OR = 1.049; 95% CI 0.980-1.118; p = 0.178; FinnGen database) or CHD prognosis (OR = 0.999; 95% CI 0.997-1.001; p = 0.391; IEU database; OR = 1.022; 95% CI 0.922-1.123; p = 0.663; FinnGen database). Reverse MR analysis showed no causal effect of CHD on H. pylori infection. Our findings further support that H. pylori infection exerts a causal effect on CHD incidence, mediated by BMI. Consequently, eradicating or preventing H. pylori infection may provide an indirect clinical benefit for patients with CHD.

Association of Pooled Fecal Microbiota on Height Growth in Children According to Enterotypes

OBJECTIVES

The association between fecal microbiota and height in children has yielded conflicting findings, warranting further investigation into potential differences in fecal bacterial composition between children with short stature and those of standard height based on enterotypes (ETs).

METHODS

According to the height z score for age and gender, the children were categorized into normal-stature (NS; n = 335) and short-stature (SS; n = 152) groups using a z score of -1.15 as a separator value. The human fecal bacterial FASTA/Q files (n = 487) were pooled and analyzed with the QIIME 2 platform with the National Center for Biotechnology Information alignment search tool. According to ETs, the prediction models by the machine learning algorithms were used for explaining SS, and their quality was validated.

RESULTS

The proportion of SS was 16.4% in ET Enterobacteriaceae (ET-E) and 68.1% in Prevotellaceae (ET-P). The Chao1 and Shannon indexes were significantly lower in the SS than in the NS groups only in ET-P. The fecal bacteria related to SS from the prediction models were similar regardless of ETs. However, in network analysis, the negative correlations between fecal bacteria in the NS and SS groups were much higher in the ET-P than in the ET-E. In the metagenome function, fecal bacteria showed an inverse association of biotin and secondary bile acid synthesis and downregulation of insulin/insulin-like growth factor-1-driven phosphoinositide 3-kinase Akt signaling and AMP-kinase signaling in the SS group compared with the NS group in both ETs.

CONCLUSION

The gut microbial compositions in children were associated with height. Strategies to modify and optimize the gut microbiota composition should be investigated for any potential in promoting height in children.

Intestinal flora and linear growth in children

The gut microbiota plays a critical role in human growth and development as well as the regulation of human pathophysiological processes. According to research, the gut microbiota controls the host's growth and development in areas such as nutrition, metabolism, endocrine hormones, and immune modulation. The human gut microbiota has an important role in child and adolescent growth, especially when nutritional conditions are poor. In this review, we focus on recent findings about the gut microbiota's influence on child growth, including the relationship between the gut microbiota and linear growth during pregnancy, infancy, childhood, and adolescence. Furthermore, we also review some mechanisms by which intestinal flora influence the host's linear growth. Although the data supports a link between intestinal flora and linear development in children, our review has limitations that prohibit us from fully verifying the causal relationship between gut flora and linear development in children. Improving the gut microbiota, in conjunction with renutrition techniques, has the potential to ameliorate the growth and development impairments currently associated with chronic illness and malnutrition in children.

Is Helicobacter pylori Anyway Pathogen in Children?

Helicobacter pylori (H. pylori) infection is a continuous challenge for both gastroenterologists and pediatricians. The international guidelines regarding diagnostic and treatment pathways differ between adults and children. The pediatric guidelines are more restrictive because children are rarely affected by serious consequences, particularly in Western countries. Therefore, infected children should be treated only after a careful case-by-case evaluation by a pediatric gastroenterologist. In any case, recent studies are confirming an increasingly all-around pathological role of H. pylori even in asymptomatic children. For these reasons, following the current evidence, we feel that H. pylori-infected children could be treated starting in pre-adolescence, particularly in Eastern countries, because their stomachs have already begun to develop the biomarkers of gastric damage. Therefore, we believe that H. pylori is anyway pathogen in children. Nevertheless, the possible beneficial role of H. pylori in humans has not yet been conclusively disproved.

Effects of Helicobacter pylori Infection on Ghrelin and Insulin-like Growth Factor 1 Secretion in Children with Idiopathic Short Stature

BACKGROUND

A diagnosis of "idiopathic short stature" (ISS) in a child means that the cause of the disease has not been established, although there are certainly some unknown factors that contributed to its occurrence. Ghrelin and leptin are important in controlling food intake; ghrelin is also a growth hormone (GH) stimulator. Both enterohormones are produced in the stomach and their secretion may be affected by a Helicobacter pylori (H. pylori) infection.

METHODS

Our study included a group of 61 children (53 prepubertal and 8 peripubertal) with ISS, without any gastrointestinal tract symptoms but in whom the histopathological evaluation of stomach tissue was made during gastroscopy to diagnose H. pylori infection. In each child, fasting ghrelin, leptin and IGF-1 concentrations, and GH levels in two stimulation tests were assessed.

RESULTS

H. pylori infection was confirmed in 24.6% of the children. Ghrelin and IGF-1 concentrations were significantly lower in H. pylori-positive than H. pylori-negative children (this was more noticeable in prepubertal subgroups), however there was not a discrepancy in regards to GH concentrations in stimulation tests, leptin levels or the nutritional state between groups.

CONCLUSIONS

Short children, infected by H. pylori seem to have lower ghrelin and IGF-1 concentrations than children without infection, this may be the reason for a worse growth rate in this subgroup.

Helicobacter pylori-Related Extraintestinal Manifestations—Myth or Reality

It is well documented that Helicobacter pylori (H. pylori) can cause both gastrointestinal and extraintestinal manifestations. The latter one represents a major burden in terms of diagnosis and treatment. H. pylori-associated systemic subclinical inflammation is mostly responsible for the development of extraintestinal manifestations, and its early eradication might result in preventing all adverse events related to their occurrence. Thus, it was suggested that H. pylori might be associated with iron deficiency anemia, thrombocytopenia (immune thrombocytopenic purpura), Schonlein Henoch purpura, failure to thrive, vitamin B12 deficiency, diabetes mellitus, body mass index, cardiovascular diseases, as well as certain neurological conditions. Nevertheless, studies showed both pros and cons in terms of the role of H. pylori in the development of previously mentioned clinical entity underlining the crucial need for further studies on these topics. Although most of these extraintestinal manifestations occur during adulthood, we must not forget that H. pylori infection is acquired mainly during childhood, and thus its early diagnosis and eradication might represent the cornerstone in the prevention of H. pylori-induced inflammatory status and consequently of all related extraintestinal conditions.

Effects of β-Carotin and Green Tea Powder Diets on Alleviating the Symptoms of Gouty Arthritis and Improving Gut Microbiota in C57BL/6 Mice

As a chronic metabolic disease caused by disorders of purine metabolism, gout has shown increasing incidence rate worldwide. Considering that gout is not easily treated and cured, further studies are explored to prevent gout development through diet modification. Both β-carotin and green tea powder are rich in dietary fiber, which helps maintain the balance of gut microbiota in humans. The aim of this study was to investigate the effects of β-carotin and green tea powder diet on the prevention of gouty arthritis in relation to the bacterial structure of gut microbiota in mice. We successfully induced gouty arthritis in C57BL/6 mice by injecting monosodium urate (MSU) crystals and feeding high-fat diet (HFD), and further investigated the effects of additional β-carotin and green tea powder in the diets of mice on the prevention of gouty arthritis in mice. Our results showed that diet of β-carotin and green tea powder reduced the joint swelling and pain in mice with gout, reduced the levels of serum uric acid (UA) and three types of pro-inflammatory cytokines, i.e., interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), improved the gut microbiota profile, and reduced the metabolic levels of purines and pyrimidines. In conclusion, our study provided evidence to support the application of β-carotin and green tea powder diet as a dietary adjustment method to prevent and treat gouty arthritis.

Association between Helicobacter pylori infection and growth outcomes in children: A meta-analysis

BACKGROUND

Multiple studies have reported the association between Helicobacter pylori (H. pylori) infection and children's growth. The results of these studies are controversial. Our meta-analysis aimed to evaluate the association between H. pylori infection and growth outcomes in children.

METHODS

We searched PubMed, Embase, Web of Science, and Cochrane Library, as well as two Chinese databases, Wanfang, and CNKI from inception to September 2019. Odds ratios (ORs) and standardized mean differences (SMDs) with their 95% confidence interval (95% CI) were selected as the effect size. We assessed pooled data using a random-effects model. Subgroup and sensitivity analyses were conducted.

RESULTS

In total, 29 studies provided data from 9384 subjects. The meta-analysis results indicated a significant association of H. pylori infection with ponderal growth disorders (OR: 2.47; 95% CI: 1.13, 5.37; p = 0.02) and linear growth disorders (OR =1.76; 95% CI: 1.15, 2.69, p = 0.01). H. pylori infection has an adverse impact on children's height-for-age Z (HAZ) scores (SMD = -0.41; 95% CI: -0.69, -0.13; p < 0.01). Pooling SMDs by other outcomes (height, weight, BMI, weight-for-age and BMI-for-age Z scores, weight-for-age percentile scores, and linear and ponderal growth velocity with/without infection and eradication/non-eradication) all indicated no significant association.

CONCLUSION

The current evidence supports the hypothesis that H. pylori infection is associated with growth outcomes in children, mainly HAZ scores. Clinicians might consider H. pylori infection in investigating linear growth disorders in children.

Gut Microbiota: The Missing Link Between Helicobacter pylori Infection and Metabolic Disorders?

Helicobacter pylori (H. pylori) is a gram-negative bacterium that infects approximately 4.4 billion individuals worldwide. Although the majority of infected individuals remain asymptomatic, this bacterium colonizes the gastric mucosa causing the development of various clinical conditions as peptic ulcers, chronic gastritis and gastric adenocarcinomas and mucosa-associated lymphoid tissue lymphomas, but complications are not limited to gastric ones. Extradigestive pathologies, including metabolic disturbances such as diabetes, obesity and nonalcoholic fatty liver disease, have also been associated with H. pylori infection. However, the underlying mechanisms connecting H. pylori with extragastric metabolic diseases needs to be clarified. Notably, the latest studies on the topic have confirmed that H. pylori infection modulates gut microbiota in humans. Damage in the gut bacterial community (dysbiosis) has been widely related to metabolic dysregulation by affecting adiposity, host energy balance, carbohydrate metabolism, and hormonal modulation, among others. Taking into account that Type 2 diabetic patients are more prone to be H. pylori positive, gut microbiota emerges as putative key factor responsible for this interaction. In this regard, the therapy of choice for H. pylori eradication, based on proton pump inhibitor combined with two or more antibiotics, also alters gut microbiota composition, but consequences on metabolic health of the patients has been scarcely explored. Recent studies from our group showed that, despite decreasing gut bacterial diversity, conventional H. pylori eradication therapy is related to positive changes in glucose and lipid profiles. The mechanistic insights explaining these effects should also be addressed in future research. This review will deal with the role of gut microbiota as the linking factor between H. pylori infection and metabolic diseases, and discussed the impact that gut bacterial modulation by H. pylori eradication treatment can also have in host's metabolism. For this purpose, new evidence from the latest human studies published in more recent years will be analyzed.

Helicobacter pylori Infection: Clinical, Endoscopic, and Histological Findings in Lebanese Pediatric Patients

BACKGROUND

Helicobacter pylori (H. pylori) is a common and universally distributed bacterial infection. However, in children, active gastritis and ulcer are rarely seen.

OBJECTIVES

The aims of this study were to establish the prevalence of H. pylori infection and to compare the clinical, endoscopic, and histopathological findings between infected and noninfected pediatric patients at Makassed General Hospital.

METHODS

Patients aged between 1 month and 17 years who underwent upper gastrointestinal endoscopy from January 2011 to January 2017 were included. The diagnosis of H. pylori was confirmed by a CLO test and/or its presence on biopsy specimens. Demographic data, clinical characteristics, endoscopic and histopathological findings, and gastritis score were recorded retrospectively.

RESULTS

During the study period, 651 children underwent upper gastrointestinal endoscopy. The main indication was abdominal pain (61%). The prevalence of H. pylori infection was 16.5%. The infection was most commonly seen among children aged between 6 and 10 years (43%). A large number of family members were associated with increased risk of infection (4.8 ± 1.5 versus 5.2 ± 1.8; p < 0.05). Epigastric pain was more associated with H. pylori (61.3% versus 14.6% in noninfected patients; p < 0.05). Nodular gastritis was commonly seen in infected patients (41.5% vs. 7.9%; p < 0.05). Mild and moderate gastritis was seen more in infected versus noninfected patients (mild: 53.8% vs. 14%; moderate: 27.4% vs. 2.4%, respectively).

CONCLUSION

Although epigastric pain was associated with H. pylori, other diagnoses should be considered since the infection are rarely symptomatic in children. Antral nodularity was associated with H. pylori infection; however, its absence does not preclude the diagnosis.

Gut Microbiota Dysbiosis in Functional Dyspepsia

Functional dyspepsia (FD) is one of the most prevalent chronic functional gastrointestinal disorders. Several distinct pathophysiological mechanisms, including gastro duodenal motor disorders, visceral hypersensitivity, brain-gut interactions, duodenal subtle inflammation, and genetic susceptibility, have been implicated in the pathogenesis of the disease, so far. However, emerging evidence suggests that both quantitative and qualitative disturbances of the gastrointestinal microbiota may also be implicated. In this context, several studies have demonstrated differences of the commensal bacterial community between patients with FD and healthy controls, while others have shown that intestinal dysbiosis might associate with disease’s symptoms severity. Elucidating these complex interactions constituting the microbiota and host crosstalk, may eventually lead to the discovery of novel, targeted therapeutic approaches that may be efficacious in treating the multiple aspects of the disorder. In this review, we summarize the data of the latest research with focus on the association between gut microbiota alterations and host regarding the pathogenesis of FD.

Association between infection and delayed growth in children: A meta-analysis

Helicobacter pylori (H. pylori) infection is associated with extra-gastrointestinal diseases in children. The present study aimed to investigate the potential association between H. pylori infection and growth in children. The PubMed, Exerpta Medica dataBASE, Cochrane Library and Chinese Biomedical Literature Database databases were comprehensively searched for relevant publications dated between January 1st 1994 and January 1st 2019. Delayed childhood growth was defined according to the age-appropriate criteria in the World Health Organization Child Growth Charts (2006 edition). The odds ratios (ORs) and 95% CIs were pooled using the fixed-effects model and subgroup and sensitivity analyses were performed using Review Manager (version 5.3; Cochrane) and STATA (version 12.0; StataCorp LP) software. A total of 15 observational studies comprising 4,199 subjects were included in the present study. A higher frequency of delayed growth was observed in H. pylori-positive children compared with that in H. pylori-negative children (OR, 1.51; 95% CI, 1.28-1.78), particularly for linear growth (OR, 1.63; 95% CI, 1.32-2.00). The aforementioned association was only observed when H. pylori infection was detected using ¹³C-urea breath tests (OR, 1.72; 95% CI, 1.22-2.40) or serum IgG antibodies targeted against H. pylori (OR, 1.81; 95% CI, 1.35-2.44). H. pylori infection was also associated with delayed childhood growth in studies with a H. pylori prevalence of ≤30% (OR, 1.71; 95% CI, 1.31-2.23) or >30% but not >50% (OR, 1.43; 95% CI, 1.10-1.86). The association between infection and growth was only statistically significant in the cross-sectional (OR, 1.43; 95% CI, 1.18-1.73) and case-control (OR, 1.81; 95% CI, 1.23-2.67) studies. No significant heterogeneity among studies was identified in the present analysis. According to Begg's and Egger's linear regression methods for funnel plots and quantification assessments, no publication bias was identified. The trim and fill method further suggested that H. pylori-positive children were prone to delayed linear growth. Therefore, the present study suggested that preventing and detecting H. pylori infection in children may be critical to ensure normal growth and development during childhood.

Levels of the Novel Endogenous Antagonist of Ghrelin Receptor, Liver-Enriched Antimicrobial Peptide-2, in Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a debilitating, chronic, inflammatory, autoimmune disease associated with cachexia. The substitutive therapy of gut hormone ghrelin has been pointed at as a potential countermeasure for the management of metabolic and inflammatory complications in RA. The recent discovery of liver-expressed antimicrobial peptide 2 (LEAP2) as an endogenous inverse agonist/antagonist of the ghrelin receptor makes feasible the development of a more rational pharmacological approach. This work aimed to assess the serum LEAP2 levels, in a cohort of RA patients, in comparison with healthy individuals and determine its correlation with inflammatory parameters. LEAP2 levels were determined by a commercial ELISA kit, plasma C-reactive protein (CRP) levels were evaluated using immunoturbidimetry, and serum levels of inflammatory mediators, namely IL-6, IL-8, IL-1β, MIP1α, MCP1, and LCN2, were measured by XMap multiplex assay. LEAP2 serum levels were significantly increased in RA patients (n = 101) compared with control subjects (n = 26). Furthermore, the LEAP2 levels significantly correlated with CRP and inflammatory cytokines, but not with BMI. These data reveal LEAP2 as a new potential RA biomarker and indicated the pharmacological control of LEAP2 levels as a novel approach for the treatment of diseases with alterations on the ghrelin levels, such as rheumatoid cachexia.

Early Gut Fungal and Bacterial Microbiota and Childhood Growth

Introduction: Childhood growth is a sensitive marker of health. Animal studies show increased height and weight velocity in the presence of fungal as well as antibiotic supplement in feed. Human studies on early gut microbiota and anthropometrics have mainly focused on bacteria only and overweight, with diverging results. We thus aimed to investigate the associations between childhood growth [height and body mass index (BMI)] and early fungal and bacterial gut microbiota. Methods: In a population-based cohort, a subset of 278 pregnant mothers was randomized to drink milk with or without probiotic bacteria during and after pregnancy. We obtained fecal samples in offspring at four time points between 0 and 2 years and anthropometric measurements 0 and 9 years. By quantitative PCR and 16S/ITS rRNA gene sequencing, children's gut microbiota abundance and diversity were analyzed against height standard deviation score (SDS) and BMI-SDS and presented as effect estimate (β) of linear mixed models. Results: From 278 included children (149 girls), 1,015 fecal samples were collected. Maternal probiotic administration did not affect childhood growth, and the groups were pooled. Fungal abundance at 2 years was positively associated with height-SDS at 2-9 years (β = 0.11 height-SDS; 95% CI, 0.00, 0.22) but not with BMI-SDS. Also, higher fungal abundance at 1 year was associated with a lower BMI-SDS at 0-1 year (β = -0.09 BMI-SDS; 95% CI, -0.18, -0.00), and both bacterial abundance and bacterial alpha diversity at 1 year were associated with lower BMI-SDS at 0-1 year (β = -0.13 BMI-SDS; 95% CI, -0.22, -0.04; and β = -0.19 BMI-SDS; 95% CI, -0.39, -0.00, respectively). Conclusions: In this prospective cohort following 0-9-year-old children, we observed that higher gut fungal abundances at 2 years were associated with taller children between 2 and 9 years. Also, higher gut fungal and bacterial abundances and higher gut bacterial diversity at 1 year were associated with lower BMI in the first year of life. The results may indicate interactions between early gut fungal microbiota and the human growth-regulating physiology, previously not reported. Clinical Trial Registration: Clinicaltrials.gov, NCT00159523.

Maternal H. pylori seropositivity is associated with gestational hypertension but is irrelevant to fetal growth and development in early childhood

BACKGROUND

Helicobacter pylori infection is known to alter growth-related hormones and affect growth in young children. However, it is still unknown whether maternal H. pylori infection has an impact on the levels of cord blood growth-related hormones and whether this can predict intrauterine growth restriction and poor physical and neurodevelopmental outcomes in children. This study aimed to examine associations between maternal H. pylori infection and pregnancy-related adverse events, fetal growth and early childhood development.

METHODS

In this prospective cohort study, we recruited singleton pregnant women without major medical illnesses from January 2014 to January 2015. Seropositivity for H. pylori was defined as > 12 U/ml of anti-H. pylori IgG in maternal serum. Demographic data and pregnancy-related medical issues of the cohort were documented. Cord blood levels of insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3), insulin, and ghrelin were determined using ELISA. The growth of the included neonates was monitored annually for up to 3 years, and cognitive development was assessed using the comprehensive developmental inventory for infants and toddlers (CDIIT) test 3 years after birth.

RESULTS

Of the 106 enrolled women, 25 (23.6%) were H. pylori-seropositive. Maternal H. pylori seropositivity was correlated with a higher risk of developing gestational hypertension (GH) (12% vs. 1.2%, p = 0.04) and lower cord blood levels of IGF-1 (< 35 ng/ml, 70.0% vs. 40.7%, p = 0.02) and IGFBP-3 (< 1120 ng/ml, 100.0% vs. 76.3%, p = 0.02) compared with the seronegative women. No significant impacts on birth weight, childhood growth and cognitive development were found to be correlated with maternal H. pylori seropositivity during pregnancy.

CONCLUSIONS

Maternal H. pylori infection during pregnancy was more likely to lead to the development of GH, but was not correlated with fetal and childhood growth and development. In addition to close monitoring of hypertension, H. pylori eradication can be considered for mothers with H. pylori infection.

Helicobacter pylori among symptomatic Egyptian children: prevalence, risk factors, and effect on growth

AIM

This study was carried out to determine the prevalence and predictors of Helicobacter pylori (H. pylori) infection among symptomatic children and the effect on growth.

METHODS

A cross-sectional study was conducted in the Outpatient Clinics of the Gastroenterology Unit of the Pediatric Hospital, Cairo University. A total of 630 children complaining of any symptoms or signs suspicious of H. pylori infection were enrolled. Weight and height were measured for each child, and the standard deviation scores (Z-scores) for weight-for-age (WAZ), weight-for-height (WHZ), and height-for-age (HAZ) were calculated. H. pylori was diagnosed using a stool antigen test.

RESULTS

The overall prevalence of infection was 64.6%. Socio-demographic variables significantly associated with H. pylori were residence in Upper Egypt (P = 0.013) and rural areas (P = 0.004), illiteracy of mothers (P = 0.017), household crowding index ≥ 3 (P = 0.011), absence of pure water supply (P = 0.005), and eating from street vendors (P < 0.001). Values of WAZ [median, interquartile range (IQR) in infected = - 1.3(- 2.7 to - 0.4) and non-infected = - 0.7(- 2.1 to - 0.1), P < 0.001], HAZ (P = 0.036), and WHZ (P = 0.005) were significantly lower in children infected with H. pylori. After performing a backward logistic regression analysis, eating from street vendors (OR = 1.879, 95% CI 1.346-2.625, P < 0.001), absence of pure water supply (OR = 1.725, 95% CI 1.162-2.561, P = 0.007), and overcrowding (OR = 1.547, 95% CI 1.100-2.177, P = 0.012) remained the significant predictors of H. pylori infection.

CONCLUSION

A high prevalence of H. pylori infection among symptomatic children was detected. The extra-digestive effects of H. pylori were revealed in the form of affection of growth parameters and reduced levels of serum hemoglobin, iron, and ferritin.

Helicobacter pylori infection in children: an overview of diagnostic methods

Children differ from adults regarding Helicobacter pylori (H. pylori) infection in many terms. H. pylori infection represents a key factor in the pathogenesis of duodenal ulcer and chronic gastritis in children. H. pylori infection causes some extraintestinal diseases as well as gastrointestinal diseases. Although, among these illnesses in children, symptoms like recurrent abdominal pain are not specific. Moreover, the role of the pathogen in the growth faltering, iron deficiency anemia, and asthma still remains controversial. A reliable method to detect H. pylori infection is a crucial issue, sand is still a matter of active debate. The tests applied for H. pylori diagnosis are grouped as either invasive or non-invasive methods. Invasive methods consist of endoscopic evaluation, the rapid urease test (RUT), histology, and bacterial culture. Non-invasive tests include the urea breath test (UBT), stool antigen test (SAT), serology, and molecular diagnostic approaches. Use of endoscopy is a pre-requisite for all invasive methods and poses difficulties in children as it is a difficult procedure and requires patient's cooperation. For this reason, the non-invasive tests have been commonly used in children, although their accuracy is not very reliable in some cases. Invasive tests may be opted to confirm the diagnosis as and when needed. This review presents the diagnostic tests used to detect H. pylori infection in children.

The need for a patient-tailored Helicobacter pylori eradication protocol prior to bariatric surgery

Objective High-quality data indicating the advantages of preoperative Helicobacter pylori screening and eradication as well the clinical outcomes of patients with and without H. pylori after bariatric surgery are lacking. Methods In total, 96 morbidly obese patients with H. pylori preparing for bariatric surgery were retrospectively reviewed. Results Of 96 biopsy specimens, 73 (76%) were positive for H. pylori on initial Giemsa staining. These patients were treated with the standard 7-day antibiotic treatment protocol corrected by the individual patient's creatinine clearance rate and body mass index and received a 30% higher dose because of their H. pylori positivity. A linear correlation was found between the effective antibiotic dose and the BMI with a recurrence rate of only 2.1% (2/96 patients). The preoperative percent estimated weight loss before surgery (17%) and in the first year of follow-up (68%-88%) was statistically equal between H. pylori-positive and -negative patients. Two early postoperative infectious complications and two postoperative surgical complications occurred in the preoperatively H. pylori-positive patients. Conclusions A patient-tailored H. pylori eradication protocol prior to bariatric surgery is mandatory to improve the eradication rate and reduce the incidence of postoperative complications in mostly asymptomatic H. pylori-positive bariatric candidates.

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.

Helicobacter pylori infection and serum leptin, obestatin, and ghrelin levels in Mexican schoolchildren

BackgroundThere is little information about the possible role of Helicobacter pylori infection on appetite-regulating peptides in children. This study evaluated the association between H. pylori infection and serum levels of ghrelin, leptin, and obestatin in schoolchildren.MethodsOne hundred seventy-eight schoolchildren, students at boarding schools in Mexico City, participated. H. pylori infection status was determined every 6 months for 1 year by a breath test using ¹³C-urea; schoolchildren with consistently positive or negative results were selected to participate. Age, sex, and body mass index (BMI) were recorded. Serum concentrations of total ghrelin, leptin, and obestatin via specific enzyme-linked immunosorbent assays were determined.ResultsSchoolchildren with H. pylori infection had lower concentration of leptin, -0.54 pg/ml (95% CI: -0.98 to -0.09), compared to the schoolchildren without infection, after adjustment by age, gender, and BMI. And the children with the infection had a median of obestatin lower in 0.99 ng/ml (95% CI: -1.93 to -0.06) compared with the uninfected children after adjustment by BMI.ConclusionAssociation was found between H. pylori infection and decreased serum concentrations of leptin and obestatin. These results suggest that in schoolchildren, H. pylori infection affects the levels of hormones implicated in regulating appetite and energy homeostasis.

Joint ESPGHAN/NASPGHAN Guidelines for the Management of Helicobacter pylori in Children and Adolescents (Update 2016)

BACKGROUND

Because of the changing epidemiology of Helicobacter pylori infection and low efficacy of currently recommended therapies, an update of the European Society for Paediatric Gastroenterology Hepatology and Nutrition/North American Society for Pediatric Gastroenterology, Hepatology and Nutrition recommendations for the diagnosis and management of H pylori infection in children and adolescents is required.

METHODS

A systematic review of the literature (time period: 2009-2014) was performed. Representatives of both societies evaluated the quality of evidence using GRADE (Grading of Recommendation Assessment, Development, and Evaluation) to formulate recommendations, which were voted upon and finalized using a Delphi process and face-to-face meeting.

RESULTS

The consensus group recommended that invasive diagnostic testing for H pylori be performed only when treatment will be offered if tests are positive. To reach the aim of a 90% eradication rate with initial therapy, antibiotics should be tailored according to susceptibility testing. Therapy should be administered for 14 days, emphasizing strict adherence. Clarithromycin-containing regimens should be restricted to children infected with susceptible strains. When antibiotic susceptibility profiles are not known, high-dose triple therapy with proton pump inhibitor, amoxicillin, and metronidazole for 14 days or bismuth-based quadruple therapy is recommended. Success of therapy should be monitored after 4 to 8 weeks by reliable noninvasive tests.

CONCLUSIONS

The primary goal of clinical investigation is to identify the cause of upper gastrointestinal symptoms rather than H pylori infection. Therefore, we recommend against a test and treat strategy. Decreasing eradication rates with previously recommended treatments call for changes to first-line therapies and broader availability of culture or molecular-based testing to tailor treatment to the individual child.

Association of obesity with Helicobacter pylori infection: A retrospective study

AIM

To explore the association between Helicobacter pylori (H. pylori) infection and obesity/weight gain in a Chinese population.

METHODS

Our primary outcome was the change in body mass index (BMI). The generalized linear models were used to explore the association between H. pylori infection and the change of BMI, and the logistic regression models were used to explore the association between H. pylori infection and obesity.

RESULTS

A total of 3039 subjects were recruited and analyzed, of which 12.8% were obese. The prevalence of H. pylori infection was 53.9% (1639/3039) overall and 54.6% (212/388) in the obese subjects. The change of BMI in the H. pylori (+) group was not significantly higher than that in the H. pylori (-) group after adjustment for potential confounding factors [RR = 0.988, 95%CI: 0.924-1.057, P = 0.729]. The prevalence of obesity decreased 1.1% in the H. pylori (+) group and 0.5% in the H. pylori (-) group. The RR of H. pylori infection for obesity was 0.831 (95%CI: 0.577-1.197, P = 0.321) after the adjustment.

CONCLUSION

H. pylori infection was not associated with overweight/obesity observed from the retrospective study in this Chinese population.

Helicobacter Pylori Infection in Texas Hispanic and Non-Hispanic White Men: Implications for Gastric Cancer Risk Disparities

Chronic Helicobacter pylori ( H. pylori) infection is a major gastric adenocarcinoma (GA) risk factor. GA disproportionately affects U.S. Hispanics compared with non-Hispanic Whites (NHWs). Since H. pylori infection studies in Hispanics are few, infection rates in Hispanic and NHW men in Bexar County were compared, and relationships with ethnicity and obesity examined. Age- and zip code-matched participants from a community-dwelling cohort were randomly selected. Sera from 284 men were analyzed by enzyme immunoassay for H. pylori antibodies. Adjusted risk ratio estimation for matched data was conducted to identify differences. Hispanics had a markedly higher prevalence of infection (30.3%) than NHWs (9.2%). Matched risk ratio (mRR) analyses revealed a strong association between H. pylori seropositivity and Hispanic ethnicity (mRR = 3.31; 95% CI [1.91, 5.73], adjusted by BMI, smoking status, and family history of cancer (mRR range = 3.28-3.89). BMI mRRs (range = 1.19-1.22) were significant in all models. In this cohort, Hispanic men had higher H. pylori infection rates than NHWs, and parallel the disproportionately higher rates of GA; obesity contributes to this higher prevalence. Future studies should address country of origin, acculturation, and other factors influencing obesity to further elucidate risk of GA in Hispanic populations.

Why were Sardinians the shortest Europeans? A journey through genes, infections, nutrition, and sex

Since ancient times the Mediterranean island of Sardinia has been known for harboring a population with an average body height shorter than almost every other ethnic group in Europe. After over a century of investigations, the cause(s) at the origin of this uniqueness are not yet clear. The shorter stature of Sardinians appears to have been documented since prehistoric times, as revealed by the analysis of skeletal remains discovered in archaeological sites on the island. Recently, a number of genetic, hormonal, environmental, infective and nutritional factors have been put forward to explain this unique anthropometric feature, which persisted for a long time, even when environmental and living conditions improved around 1960. Although some of the putative factors are supported by sound empirical evidence, weaker support is available for others. The recent advent of whole genome analysis techniques shed new light on specific variants at the origin of this short stature. However, the marked geographical variability of stature across time and space within the island, and the well-known presence of pockets of short height in the population of the southern districts, are still puzzling findings that have attracted the interest of anthropologists and geneticists. The purpose of this review is to focus on the state-of-the-art research on stature, as well as the factors that made Sardinians the shortest among Europeans.

Effects of Helicobacter pylori eradication on insulin resistance and metabolic parameters: a systematic review and meta-analysis

INTRODUCTION

Previous studies have shown a close relationship between Helicobacter pylori (H. pylori), insulin resistance, and altered metabolic parameters. However, the effects of H. pylori eradication on these conditions remain controversial. We carried out a systematic review and meta-analysis to evaluate the effects of H. pylori eradication on insulin resistance and metabolic parameters.

METHODS

We searched CENTRAL, MEDLINE, and EMBASE databases from their inception to July 2016. Insulin resistance (HOMA-IR), body weight (BW), BMI, waist circumference, triglycerides (TG), high-density and low-density lipoprotein-cholesterol (HDL-C and LDL-C), and fasting blood glucose (FBG) were compared between patients with and without H. pylori eradication using a random-effects model. We reported pooled mean differences (MD) and 95% confidence intervals (CI) for the change in outcomes.

RESULTS

Data from five studies showed no difference in HOMA-IR after H. pylori eradication (pooled MD=-0.52, 95% CI: -1.47 to 0.42). Eradication significantly increased BMI (MD=0.36, 95% CI: 0.11-0.60) and BW (MD=1.1, 95% CI: 0.8-1.5), but had no significant effects on TG, LDL-C, HDL-C, or FBG.

CONCLUSION

H. pylori eradication does not improve insulin resistance, TG, HDL-C, LDL-C, or FBG, but may increase BW and BMI. Further studies are needed to clarify the effect of H. pylori eradication on metabolism.

Helicobacter pylori Infection and Children's Growth: An Overview

OBJECTIVES

Helicobacter pylori infection is acquired in early childhood, yet its role in children's health is still not fully clear. In this narrative review, we focused on the association between H pylori infection and children's growth.

METHODS

A literature search of the Ovid MEDLINE (till June 2015) and EMBASE (till August 2015) databases was performed using the terms "Helicobacter pylori, growth, body height, growth disorders and child development." Original studies that addressed the association between H pylori infection or eradication and children's growth were reviewed and the risk of bias of each study was assessed.

RESULTS

The existing evidence is based on observational studies (N = 48) and suggests that H pylori infection may adversely influence children's growth; findings were more consistent across studies with low risk of bias. Regarding linear growth, observational studies have repeatedly linked between H pylori infection and slower or diminished linear growth; yet, it is not known whether this association is causal. The association between H pylori infection and ponderal growth has been less consistent. Scarce evidence exists on the effect of H pylori eradication on children's skeletal growth and weight gain, but there is an indication that H pylori eradication may benefit nutritional status.

CONCLUSIONS

H pylori infection may impair children's growth. Additional studies, especially clinical trials, are needed to elucidate the role of H pylori eradication in children's growth, and the mechanisms that may be involved in such.

Comparison of Gene Expression Between Pediatric and Adult Gastric Mucosa with Helicobacter pylori Infection

BACKGROUND

Although Helicobacter pylori infection among adults is a major risk factor for the development of gastric cancer and initial infection with H. pylori may occur before 5 years of age, the direct effects of H. pylori infection since childhood on gastric mucosa are unknown. The aim of this study was to evaluate gene expression in the H. pylori-infected gastric mucosa of children.

METHODS

Gastric mucosal samples were obtained from 24 patients (12 adults and 12 children) who had undergone endoscopic evaluation of chronic abdominal complaints and were examined by the adult and pediatric gastroenterologists at Juntendo University Hospital. Six adult and pediatric patients with and six without H. pylori infection were enrolled. Their gastric mucosal samples obtained from the antrum and corpus were used for microarray, real-time polymerase chain reaction, and immunohistochemical analyses to examine the expression of inflammatory carcinogenic molecules.

RESULTS

The expression of inflammatory molecules was upregulated in the H. pylori-infected gastric mucosa from both adults and children. The expression of olfactomedin-4 was only upregulated in adult patients, while that of pim-2, regenerating islet-derived 3 alpha, lipocalin-2, and C-X-C motif chemokine ligand 13 was equally upregulated in the infected gastric mucosa of both adults and children.

CONCLUSIONS

Because several carcinogenic molecules are upregulated in H. pylori-infected gastric mucosa even in children, early eradication therapy from childhood may be beneficial to decrease the incidence of gastric cancer. Although increased expression of olfactomedin-4 can be important in suppressing gastric cancer in adults, the increase was not detected in children.

Impact of Helicobacter pylori infection on serum and gastric tissue nucleobindin 2/nesfatin-1 levels

AIM: To investigate the impact of Helicobacter pylori (H. pylori) infection on serum and gastric tissue levels of nucleobindin2 (NUCB2)/nesfatin-1 in humans.

METHODS: Serum and mucosal samples were collected from 83 asymptomatic volunteers who received gastroscopy and had H. pylori infection confirmed by ¹³C breath test, rapid urease test and Warth-Starry staining. The subjects were divided into an H. pylori positive group and an H. pylori negative group. Serum NUCB2/nesfatin-1 concentration was measured by enzyme-linked immunosorbent assay (ELISA) and the expression of NUCB2 mRNA in gastric mucosa was detected by real-time quantitative polymerase chain reaction.

RESULTS: Serum NUCB2/nesfatin-1 concentrations in the H. pylori positive and negative groups did not differ significantly (2.298 ng/mL ± 0.275 ng/mL vs 2.267 ng/mL ± 0.201 ng/mL, P > 0.05). The expression level of NUCB2 mRNA in the H. pylori positive group was significantly higher than that in the H. pylori negative group (1.336 ± 0.324 vs 0.914 ± 0.171, P < 0.01).

CONCLUSION: H. pylori infection induces the upregulation of NUCB2 mRNA in the gastric mucosa, but has no effect on serum NUCB2/nesfatin-1 concentration.

Metabolic Interaction of Helicobacter pylori Infection and Gut Microbiota

As a barrier, gut commensal microbiota can protect against potential pathogenic microbes in the gastrointestinal tract. Crosstalk between gut microbes and immune cells promotes human intestinal homeostasis. Dysbiosis of gut microbiota has been implicated in the development of many human metabolic disorders like obesity, hepatic steatohepatitis, and insulin resistance in type 2 diabetes (T2D). Certain microbes, such as butyrate-producing bacteria, are lower in T2D patients. The transfer of intestinal microbiota from lean donors increases insulin sensitivity in individuals with metabolic syndrome, but the exact pathogenesis remains unclear. H. pylori in the human stomach cause chronic gastritis, peptic ulcers, and gastric cancers. H. pylori infection also induces insulin resistance and has been defined as a predisposing factor to T2D development. Gastric and fecal microbiota may have been changed in H. pylori-infected persons and mice to promote gastric inflammation and specific diseases. However, the interaction of H. pylori and gut microbiota in regulating host metabolism also remains unknown. Further studies aim to identify the H. pylori-microbiota-host metabolism axis and to test if H. pylori eradication or modification of gut microbiota can improve the control of human metabolic disorders.

Elderly women who received Helicobacter pylori-eradicating therapy have reduced risk of low skeletal muscle mass

BACKGROUND

Sarcopenia is associated with adverse outcomes such as physical disability, poorer quality of life, and death. Helicobacter pylori (HP) eradication increases ghrelin secretion, which may be a possible treatment for sarcopenia. We investigated whether HP eradication reduces the risk of low muscle mass (LMM), which is an integral component of sarcopenia.

MATERIALS AND METHODS

Healthy, asymptomatic women aged ≥60 years who participated in a health screening program were enrolled. Subjects with a history of HP eradication were compared with those who were HP IgG(+), but had not received HP-eradicating therapy. Body composition was measured by multifrequency bioelectrical impedance analysis. LMM was defined as body muscle mass 2 standard deviations below the mean muscle mass of healthy women aged 20-39 years from the same program. Multivariable analysis was used to identify sarcopenia risk factors.

RESULTS

Three hundred seventy-two women had received HP eradication, while 689 HP IgG(+) women had not. The prevalence of LMM was significantly lower in those who received HP eradication (13.7% vs 21.6%, P=0.002). Multivariable analysis identified risk factors for LMM as age, white blood cell count, serum total protein concentration, and the metabolic syndrome. HP eradication (odds ratio: 0.632, 95% confidence interval: 0.440-0.824, P=0.013) was a significant preventive factor, and exercise (odds ratio: 0.710, 95% confidence interval: 0.504-1.002, P=0.051) had a preventive tendency.

CONCLUSION

HP eradication might reduce LMM risk. This finding should be confirmed in prospective longitudinal studies to determine the long-term effects of HP eradication on sarcopenia.

The relationship between Helicobacter pylori seropositivity and COPD

RATIONALE

Chronic systemic infections such as those with Helicobacter pylori (H. pylori) may contribute to the evolution and progression of chronic obstructive pulmonary disease (COPD). Using data from the Lung Health Study (LHS), we determined the relationship of H. pylori infection with the severity and progression of COPD.

METHODS

Using an immunoassay, we measured H. pylori immunoglobulin G (IgG) antibody titres in serum samples of 4765 patients with mild-to-moderate COPD. We then determined their relationship with the individual's FEV1 and the rate of decline in FEV1 and mortality over 11 years using multiple regression analysis.

RESULTS

Approximately 18% of the patients were seropositive to H. pylori and these individuals demonstrated lower FEV1 (L) values at every study visit compared with individuals who were seronegative for H. pylori (p value=0.00012). However, patients with seropositivity to H. pylori were on average 0.012 m shorter than those with seronegativity (p value=0.0015). The significant relationship between FEV1 and H. pylori seropositivity disappeared when FEV1 per cent predicted (FEV1pp) was used (p value=0.45). H. pylori seropositive individuals had greater circulating C reactive protein (CRP) levels compared with H. pylori seronegative individuals (p value=0.012), and had increased risk of cardiovascular mortality (relative risk 1.61, p=0.05).

CONCLUSIONS

H. pylori infection was associated with reduced lung function that is most likely due to the effect of the bacterium on lung growth earlier in life. It is also associated with systemic inflammation and increased risk of cardiovascular mortality in patients with COPD.

TRIAL REGISTRATION NUMBERS

NCT00000568 and NCT00000569.

Effect of Helicobacter pylori infection on gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a common chronic disease of the digestive system. In recent years, due to the better understanding of Helicobacter pylori (H. pylori) and the wide clinical application of proton pump inhibitors, the rate of H. pylori infection is declining, while the incidence of GERD is increasing. This phenomenon suggests a possible relationship between H. pylori infection and the incidence of GERD. The pathogenesis of GERD is related to the dysfunction of the protective esophageal barrier, esophageal motility, gastric acidity and gastric emptying, and H. pylori infection may affect these factors to exert an impact on the incidence of GERD.

Prevention of Helicobacter pylori infection in childhood

Helicobacter pylori (H. pylori) infection is one of the most common infections worldwide. Although infection rates are falling in the developed and developing countries, H. pylori is still widespread in the world. This article has reviewed the important publications on H. pylori in childhood with a focus on its evolving transmission route and the source of infection and preventive strategies in childhood, PubMed was searched up to identify eligible studies. Relevant publications were searched using the following.

Review article: Associations between Helicobacter pylori and obesity--an ecological study

BACKGROUND

There is emerging debate over the effect of Helicobacter pylori infection on body mass index (BMI). A recent study demonstrated that individuals who underwent H. pylori eradication developed significant weight gain as compared to subjects with untreated H. pylori colonisation.

AIM

To elucidate the association between H. pylori colonisation and the prevalence of overweight and obesity in developed countries.

METHODS

The literature was searched for publications reporting data on H. pylori prevalence rates and obesity prevalence rates. Studies selected reported H. pylori prevalence in random population samples with sample sizes of more than 100 subjects in developed countries (GDP >25,000 US$/person/year). Corresponding BMI distributions for corresponding countries and regions were identified. Nonparametric tests were used to compare the association between H. pylori and overweight and obesity rates.

RESULTS

Forty-nine studies with data from 10 European countries, Japan, the US and Australia were identified. The mean H. pylori rate was 44.1% (range 17-75%), the mean rates for obesity and overweight were 46.6 (± 16)% and 14.2 (± 8.9)%. The rate of obesity and overweight were inversely and significantly (r = 0.29, P < 0.001) correlated with the prevalence of H. pylori infection.

CONCLUSIONS

There is an inverse correlation between H. pylori prevalence and rate of overweight/obesity in countries of the developed world. Thus, the gradual decrease of the H. pylori colonisation that has been observed in recent decades (or factors associated with decrease of) could be causally related to the obesity endemic observed in the Western world.

Metabolic consequences of Helicobacter pylori infection and eradication

Helicobacter pylori (H. pylori) is still the most prevalent infection of the world. Colonization of the stomach by this agent will invariably induce chronic gastritis which is a low-grade inflammatory state leading to local complications (peptic ulcer, gastric cancer, lymphoma) and remote manifestations. While H. pylori does not enter circulation, these extragastric manifestations are probably mediated by the cytokines and acute phase proteins produced by the inflammed mucosa. The epidemiologic link between the H. pylori infection and metabolic changes is inconstant and controversial. Growth delay was described mainly in low-income regions with high prevalence of the infection, where probably other nutritional and social factors contribute to it. The timely eradication of the infection will lead to a more healthy development of the young population, along with preventing peptic ulcers and gastric cancer An increase of total, low density lipoprotein and high density liporotein cholesterol levels in some infected people creates an atherogenic lipid profile which could promote atherosclerosis with its complications, myocardial infarction, stroke and peripheral vascular disease. Well designed and adequately powered long-term studies are required to see whether eradication of the infection will prevent these conditions. In case of glucose metabolism, the most consistent association was found between H. pylori and insulin resistance: again, proof that eradication prevents this common metabolic disturbance is expected. The results of eradication with standard regimens in diabetics are significantly worse than in non-diabetic patients, thus, more active regimens must be found to obtain better results. Successful eradication itself led to an increase of body mass index and cholesterol levels in some populations, while in others no such changes were encountered. Uncertainities of the metabolic consequences of H. pylori infection must be clarified in the future.

Brain-gut axis in the pathogenesis of Helicobacter pylori infection

Helicobacter pylori (H. pylori) infection is the main pathogenic factor for upper digestive tract organic diseases. In addition to direct cytotoxic and proinflammatory effects, H. pylori infection may also induce abnormalities indirectly by affecting the brain-gut axis, similar to other microorganisms present in the alimentary tract. The brain-gut axis integrates the central, peripheral, enteric and autonomic nervous systems, as well as the endocrine and immunological systems, with gastrointestinal functions and environmental stimuli, including gastric and intestinal microbiota. The bidirectional relationship between H. pylori infection and the brain-gut axis influences both the contagion process and the host’s neuroendocrine-immunological reaction to it, resulting in alterations in cognitive functions, food intake and appetite, immunological response, and modification of symptom sensitivity thresholds. Furthermore, disturbances in the upper and lower digestive tract permeability, motility and secretion can occur, mainly as a form of irritable bowel syndrome. Many of these abnormalities disappear following H. pylori eradication. H. pylori may have direct neurotoxic effects that lead to alteration of the brain-gut axis through the activation of neurogenic inflammatory processes, or by microelement deficiency secondary to functional and morphological changes in the digestive tract. In digestive tissue, H. pylori can alter signaling in the brain-gut axis by mast cells, the main brain-gut axis effector, as H. pylori infection is associated with decreased mast cell infiltration in the digestive tract. Nevertheless, unequivocal data concerning the direct and immediate effect of H. pylori infection on the brain-gut axis are still lacking. Therefore, further studies evaluating the clinical importance of these host-bacteria interactions will improve our understanding of H. pylori infection pathophysiology and suggest new therapeutic approaches.

Helicobacter pylori infection and extragastric disorders in children: a critical update

Helicobacter pylori (H. pylori) is a highly prevalent, serious and chronic infection that has been associated causally with a diverse spectrum of extragastric disorders including iron deficiency anemia, chronic idiopathic thrombocytopenic purpura, growth retardation, and diabetes mellitus. The inverse relation of H. pylori prevalence and the increase in allergies, as reported from epidemiological studies, has stimulated research for elucidating potential underlying pathophysiological mechanisms. Although H. pylori is most frequently acquired during childhood in both developed and developing countries, clinicians are less familiar with the pediatric literature in the field. A better understanding of the H. pylori disease spectrum in childhood should lead to clearer recommendations about testing for and treating H. pylori infection in children who are more likely to develop clinical sequelae. A further clinical challenge is whether the progressive decrease of H. pylori in the last decades, abetted by modern clinical practices, may have other health consequences.

Helicobacter pylori infection in obesity and its clinical outcome after bariatric surgery

The present review summarizes the prevalence and active clinical problems in obese patients with Helicobacter pylori (H. pylori) infection, as well as the outcomes after bariatric surgery in this patient population. The involvement of H. pylori in the pathophysiology of obesity is still debated. It may be that the infection is protective against obesity, because of the gastritis-induced decrease in production and secretion of the orexigenic hormone ghrelin. However, recent epidemiological studies have failed to show an association between H. pylori infection and reduced body mass index. H. pylori infection might represent a limiting factor in the access to bariatric bypass surgery, even if high-quality evidence indicating the advantages of preoperative H. pylori screening and eradication is lacking. The clinical management of infection is complicated by the lower eradication rates with standard therapeutic regimens reported in obese patients than in the normal-weight population. Prospective clinical studies to ameliorate both H. pylori eradication rates and control the clinical outcomes of H. pylori infection after different bariatric procedures are warranted.

Unintended consequences of Helicobacter pylori infection in children in developing countries: iron deficiency, diarrhea, and growth retardation

Helicobacter pylori infection is predominantly acquired early in life. The prevalence of the infection in childhood is low in developed countries, whereas in developing countries most children are infected by 10 y of age. In poor resource settings, where malnutrition, parasitic/enteropathogen and H. pylori infection co-exist in young children, H. pylori might have potentially more diverse clinical outcomes. This paper reviews the impact of childhood H. pylori infection in developing countries that should now be the urgent focus of future research. The extra-gastric manifestations in early H. pylori infection in infants in poor resource settings might be a consequence of the infection associated initial hypochlorhydria. The potential role of H. pylori infection on iron deficiency, growth impairment, diarrheal disease, malabsorption and cognitive function is discussed in this review.

What do we know about benefits of H. pylori treatment in childhood?

Policy analysis shows that H. pylori test and treat strategies targeting adults at moderate to high risk of H. pylori-induced disease is likely to be cost-effective for preventing digestive diseases responsible for a large global disease burden. Little is known, however, about health benefits to children from eliminating this infection. We conducted a systematic review of the evidence regarding health benefits to children from treatment to eliminate H. pylori infection.   We systematically searched Ovid MEDLINE for pertinent review articles published through 2012. We excluded reviews focused on treatment efficacy and scrutinized reference lists of selected reviews to identify additional eligible reviews. Fifteen reviews met specified inclusion criteria. Overall, they show that few reported studies investigating pediatric health effects of treatment for H. pylori infection were well designed with adequate statistical power. Thus, there is insufficient evidence for drawing conclusions about health benefits to children from treatment to eliminate H. pylori infection.