Endocrine impact of Helicobacter pylori: Focus on ghrelin and ghrelin o-acyltransferase

Causal relationships of Helicobacter pylori and related gastrointestinal diseases on Type 2 diabetes: Univariable and Multivariable Mendelian randomization

BACKGROUND

Previous observational studies have demonstrated a connection between the risk of Type 2 diabetes mellitus (T2DM) and gastrointestinal problems brought on by Helicobacter pylori (H. pylori) infection. However, little is understood about how these factors impact on T2DM.

METHOD

This study used data from the GWAS database on H. pylori antibodies, gastroduodenal ulcers, chronic gastritis, gastric cancer, T2DM and information on potential mediators: obesity, glycosylated hemoglobin (HbA1c) and blood glucose levels. Using univariate Mendelian randomization (MR) and multivariate MR (MVMR) analyses to evaluate the relationship between H. pylori and associated gastrointestinal diseases with the risk of developing of T2DM and explore the presence of mediators to ascertain the probable mechanisms.

RESULTS

Genetic evidence suggests that H. pylori IgG antibody (P = 0.006, b = 0.0945, OR = 1.0995, 95% CI = 1.023-1.176), H. pylori GroEL antibody (P = 0.028, OR = 1.033, 95% CI = 1.004-1.064), gastroduodenal ulcers (P = 0.019, OR = 1.036, 95% CI = 1.006-1.068) and chronic gastritis (P = 0.005, OR = 1.042, 95% CI = 1.012-1.074) are all linked to an increased risk of T2DM, additionally, H. pylori IgG antibody is associated with obesity (P = 0.034, OR = 1.03, 95% CI = 1.002-1.055). The results of MVMR showed that the pathogenic relationship between H. pylori GroEL antibody and gastroduodenal ulcer in T2DM is mediated by blood glucose level and obesity, respectively.

CONCLUSION

Our study found that H. pylori IgG antibody, H. pylori GroEL antibody, gastroduodenal ulcer and chronic gastritis are all related to t T2DM, and blood glucose level and obesity mediate the development of H. pylori GroEL antibody and gastroduodenal ulcer on T2DM, respectively. These findings may inform new prevention and intervention strategies for T2DM.

Gut peptide changes in patients with obstructive jaundice undergoing biliary drainage: A prospective case control study

BACKGROUND

Biliary obstruction is a relatively common condition that affects approximately 5 in 1000 people annually. Malnutrition is very common in patients with biliary obstruction and since it is associated with significant morbidity and mortality, it is important to identify factors and mechanisms involved in its development.

AIM

To determine the influence of obstructive jaundice on the hormones controlling appetite and nutritive status.

METHODS

This was a prospective case control study performed in a tertiary center in Zagreb, Croatia. Patients with biliary obstruction undergoing internal biliary drainage from September 2012 until August 2013 were enrolled. After excluding patients who developed procedure related complications or were lost in the follow-up, out of initial 73 patients, 55 patients were included in the analysis, including 34 with benign and 21 with malignant disease. Meanwhile, 40 non-jaundiced controls were also included. Appetite, nutritional status, and serum ghrelin, cholecystokinin (CCK), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α) were determined at admission, 48 h and 28 d after internal biliary drainage. Chi square test was used for categorical variables. Continuous variables were analysed for normality by Kolmogorov–Smirnov test and relevant non-parametric (Mann-Whitney, Kruskal-Wallis, and Friedman) or parametric (t-test and analysis of variance) tests were used.

RESULTS

Patients with obstructive jaundice were significantly malnourished compared to controls, regardless of disease etiology. Plasma ghrelin and CCK levels were significantly higher in patients with obstructive jaundice. Serum bilirubin concentrations were negatively correlated with ghrelin levels and positively correlated with TNF-α, but had no correlation with CCK concentrations. After internal biliary drainage, a significant improvement of nutritional status was observed although serum concentrations of ghrelin, IL-6, and TNF-α remained significantly elevated even 28 d after the procedure. CCK levels in patients without malnutrition remained elevated 28 d after the procedure, but in patients with malnutrition, CCK levels decreased to levels comparable with those in the control group. We have not established any correlation between appetite and serum levels of ghrelin, CCK, IL-6, and TNF-α before and after biliary drainage.

CONCLUSION

Possible abnormalities in ghrelin and CCK regulation may be associated with the development of malnutrition during the inflammatory response in patients with biliary obstruction.

Rapamycin Attenuates Anxiety and Depressive Behavior Induced by Helicobacter pylori in Association with Reduced Circulating Levels of Ghrelin

Background. Helicobacter pylori (H. pylori) infection is closely associated with depression and development of neuroinflammation. The aim of this study is to explore the relationship between H. pylori, depression, and circulating levels of ghrelin. Methods. Mice were randomly divided into three groups: healthy control group (gavaged sterile saline and injected with saline, $n=8$ ); H. pylori+saline group (gavaged H. pylori and injected with saline, $n=8$ ); and H. pylori+rapa group (gavaged H. pylori and injected with rapamycin, $n=8$ ). Open field test (OFT), sucrose preference test (SPT), forced swim test (FST), and tail suspension test (TST) were used for anxiety and depressive behavior test. Western blotting was utilized to assess mTOR, p-mTOR, and GSMD expression, and serum ghrelin levels were estimated using ELISA. Results. In the OFT, the control mice moved more and exhibited a increase in crossing number relative to the H. pylori+saline mice (all $P<0.05$ ). Increased quantity of fecal boli can be indicative of increased anxiety and emotionality of the subject animal. H. pylori+saline mice exhibited an increase in fecal boli when compared to control mice and H. pylori+rapa mice ( $P<0.05$ ). H. pylori infected mice decreasing the expression of ghrelin. The protein levels of p-mTOR/mTOR in the gastric antrum mTOR signaling activation and low-level ghrelin in H. pylori-infect mice compared to those in control mice (all P <0.001). Compared with single H. pylori infection, mTOR inhibitors increased the ghrelin secretion of H. pylori infection to a certain extent ( $P<0.05$ ). The protein levels of GSDMD expression significantly increase in hippocampus of H. pylori-infected mice ( $P<0.001$ ). Rapamycin treatment inhibited expression of GSDMD in H. pylori-infected mice ( $P<0.05$ ). Conclusions. H. pylori infection is associated with increased expression of mTOR and decreased circulating levels of ghrelin. Elevated pyroptosis in the brain and anxiety- and depressed-like behaviors occur when ghrelin levels are suppressed.

Factors associated with gastro-duodenal ulcer in compensated type 2 diabetic patients: a Romanian single-center study

INTRODUCTION

Helicobacter pylori infection is accepted as the leading cause of chronic gastritis, ulcer disease and gastric cancer, with an important impact on health care burden, especially in countries with a high prevalence of infection. The aim of the study was to investigate the influence of H. pylori infection, medication, associated medical conditions or social habits on endoscopic ulcer occurrence in the compensated type 2 diabetic population.

MATERIAL AND METHODS

Two hundred and sixty type 2 diabetic patients investigated on endoscopy (57 patients with peptic ulcer and 203 controls) with a complete set of biopsies, demographic and medical data were enrolled.

RESULTS

On univariate regression analysis, H. pylori infection (42.1% vs. 35.5%, p = 0.359) or a history of peptic ulcer (61.4% vs. 61.6%, p = 0.981) was not a predictor for ulcer on endoscopy in the diabetic population, and heartburn was more frequent in diabetics without ulcer (21.2% vs. 8.8%, p = 0.033). Anemia was the best predictor for ulcer on endoscopy in both diabetics with (p < 0.001, OR = 4.77, 95% CI: 2.02-11.28) and without (p = 0.027, OR = 2.76, 95% CI: 1.10-6.91) chronic proton pump inhibitor (PPI) therapy. In diabetic patients on PPI more than 1 month anticoagulants - acenocoumarol or low-weight molecular heparin (p = 0.038, OR = 2.37, 95% CI: 1.04-5.40), low-dose aspirin 75-125 mg/day (p = 0.029, OR = 2.61, 95% CI: 1.08-6.28) and alcohol consumption (p = 0.015, OR = 2.70, 95% CI: 1.19-6.13) were predictors for ulcer on endoscopy.

CONCLUSIONS

In diabetic patients, anemia is the most important predictor for ulcer on endoscopy, but not H. pylori or digestive symptoms, while low-dose aspirin or anticoagulant therapy and alcohol consumption are the most important predictors for ulcer in diabetics on chronic proton pump inhibitor therapy.

Anti-diabetics and antimicrobials: Harmony of mutual interplay

Diabetes is one of the four major non-communicable diseases, and appointed by the world health organization as the seventh leading cause of death worldwide. The scientists have turned over every rock in the corners of medical sciences in order to come up with better understanding and hence more effective treatments of diabetes. The continuous research on the subject has elucidated the role of immune disorders and inflammation as definitive factors in the trajectory of diabetes, assuring that blood glucose adjustments would result in a relief in the systemic stress leading to minimizing inflammation. On a parallel basis, microbial infections usually take advantage of immunity disorders and propagate creating a pro-inflammatory environment, all of which can be reversed by antimicrobial treatment. Standing at the crossroads between diabetes, immunity and infection, we aim in this review at projecting the interplay between immunity and diabetes, shedding the light on the overlapping playgrounds for the activity of some antimicrobial and anti-diabetic agents. Furthermore, we focused on the anti-diabetic drugs that can confer antimicrobial or anti-virulence activities.

Detrimental relevance of Helicobacter pylori infection with sarcopenia

BACKGROUND

Helicobacter pylori (H. pylori), Gram negative microaerophilic bacteria, is a well-known pathogen of many gastrointestinal diseases. But several emerging evidences suggest it role in numerous other extra-gastric diseases. The current study investigates the relationship between H. pylori infection and sarcopenia, a clinical condition characterized by the loss of mass and function of skeletal muscle. A total of 3453 eligible participants from the Third National Health and Nutrition Examination Survey (NHANES III), the United States, were enrolled. Based on the serum laboratory results, subjects were categorized into three groups: normal (without evidence of any H. pylori infection), anti-H. pylori IgG positive [H. pylori (+)], and concurrent anti-H. pylori IgG and anti-cytotoxin-associated gene A IgG positive [CagA (+)]. Sarcopenia was determined as having a skeletal muscle index (SMI) value that is more than 1 standard deviation away from the mean value of sex-specific, healthy young adults between 20 and 39 years old. Risk of sarcopenia and its components are compared between subgroups.

RESULTS

Odds ratios (OR) for confirmed diagnosis of sarcopenia were higher in H. pylori (+) (OR = 2.052, 95% CI 1.697-2.481, p < 0.001) and CagA (+) (OR = 1.585, 95% CI 1.278-1.965, p < 0.001) groups. Moreover, negative beta regression coefficient of SMI were shown in H. pylori (+) (β: - 0.023, p < 0.001) and CagA (+) (β: - 0.017, p < 0.001). Sub-analyses which categorized participants by gender revealed that absolute value of beta regression coefficient for SMI were higher in female in H. pylori (+) subgroup (β: - 1.745 in male and - 2.942 in female, p were both < 0.001), and the CagA (+) subgroup (β: - 1.407 in male and - 2.159 in female, p were both < 0.001).

CONCLUSIONS

Positive serum H. pylori infectious markers including anti-H. pylori antibody and CagA seropositivity are correlated with sarcopenia and low muscle quantity. Therefore, H. pylori eradication therapy may bring benefits to sarcopenia patients with concurrent active H. pylori infection.

Contribution of Ghrelin to the Pathogenesis of Growth Hormone Deficiency

In this review we described the interactions between ghrelin and the growth hormone (GH)-insulin-like growth factor 1 (IGF-1) axis in children and adults with growth hormone deficiency (GHD). A possible involvement of these interactions in the pathogenesis of unexplained cases of GHD was suggested. Current research provides more and more details to the knowledge on the circadian rhythm of ghrelin. We gathered reports on the decreasing effect of Helicobacter pylori-related chronic gastritis on the number of ghrelin immunopositive cells and the consequent decrease in ghrelin serum concentration. The gastrointestinal tract microflora modification of the ghrelin action, by the mechanism of molecular mimicry, was also stressed. Moreover, the mutual relationships between ghrelin and the TSH-FT4/FT3 axis in growth and metabolic processes are described. It is to be recalled that FT4 and FT3 exert a permissive impact on IGF-1 action and, in turn, GH, in reaction mediated by IGF-1, enhances the monodeiodination of FT4 to FT3. Finally, we discussed the latest attempts to use the GH secretagogue receptor (GHS-R) analogues for possible diagnostic and therapeutic purposes.

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.

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.

The Interaction of Helicobacter pylori Infection and Type 2 Diabetes Mellitus

Helicobacter pylori is one of the most common human pathogens that can cause gastrointestinal (GI) disorders, including simple gastritis, gastric ulcer, and malignant gastritis. In some cases, such as immunodeficiency and underlying diseases, it can be problematic as opportunistic infections. Diabetes mellitus (type 2) (T2DM) is one of the H. pylori underlying diseases. Since GI problems are observed in diabetic patients, it is necessary to treat H. pylori infection. In this review, we aimed to evaluate the possible relationship between H. pylori and T2DM according to epidemiological surveys of 70 studies retrieved from databases, including Scopus, PubMed, and Google Scholar about the relationship between H. pylori and T2DM, and discuss the reported background mechanisms of this correlation. According to the results of our study, the different studies have shown that H. pylori is more prevalent in Type 2 diabetic patients than healthy individuals or nondiabetic patients. The reason is development of H. pylori infection-induced inflammation and production of inflammatory cytokines as well as different hormonal imbalance by this bacterium, which are associated with diabetes mellitus. On the other hand, by tracing anti-H. pylori antibodies in patients with diabetes mellitus and occurrence of symptoms such as digestive problems in >75% of these patients, it can be concluded that there is a relationship between this bacterium and T2DM. Considering the evidence, it is crucially important that the probability of infection with H. pylori is evaluated in patients with T2DM so that medical process of the patient is followed with higher cautious.

Helicobacter pylori infection increases risk of incident metabolic syndrome and diabetes: A cohort study

Emerging studies have shed light on the association between Helicobacter pylori (HP) infection and cardiometabolic risk. However, there is no evidence to support a causal link for the relationship in the general population. Our aim was to determine whether HP infection is associated with the risks of incident type II diabetes mellitus (DM) in a population-based cohort consisting of adults from the general population. A total of 69235 adults enrolled in the study obtained health examinations at the Tri-Service General Hospital in Taiwan from 2010 to 2016. HP infection detection was performed by rapid urease tests (RUTs), and endoscopic examinations were used to diagnose gastroesophageal reflux disease (GERD), gastric ulcers (GUs) and duodenal ulcers (DUs). Cross-sectional and longitudinal analyses were performed to examine the association between HP infection and cardiometabolic diseases using logistic regression and Cox regression in a large population-based study. HP infection was significantly associated with the presence of metabolic syndrome (MetS) (OR = 1.26, 95%CI: 1.00-1.57) and DM (OR = 1.59, 95%CI: 1.17-2.17) only in male subjects, and abnormal endoscopic findings were also correlated with cardiometabolic diseases. Our findings demonstrated that participants with HP infection had an elevated risk of developing incident DM (HR = 1.54, 95%CI: 1.11-2.13). In addition, endoscopic findings of a DU (HR = 1.63, 95%CI: 1.02-2.63), rather than GERD or a GU, were also predictive of incident DM. In this cohort, HP infection was a statistically significant predictor of incident DM among male population.

Possible association of ghrelin/obestatin balance with cardiometabolic risk in obese subjects with Helicobacter pylori

OBJECTIVES

Helicobacter pylori (H. pylori) is a common gastric infection associated with extragastric conditions. The association between H. pylori infection and obesity is unclear. H. pylori may affect gut hormones involved in food intake and energy expenditure. The aim of this study is to evaluate ghrelin/obestatin balance and leptin in obese subjects with H. pylori infection.

METHODS

Sixty healthy volunteers were divided into: obese and non-obese groups. Each group was divided into H. Pylori positive or H. pylori negative. Anthropometric parameters, H. pylori status, serum glucose, insulin level, and lipid profile were estimated with calculation of Homeostasis Model Assessment Insulin Resistance (HOMA-IR). Serum levels of ghrelin, obestatin, and leptin were evaluated.

RESULTS

Significant increase was found in serum glucose, insulin and HOMA-IR ratio in obese subjects with positive H. pylori as compared to other groups. H. pylori positive obese subjects showed significantly increased ghrelin, ghrelin/obestatin balance, and leptin with a significant decrease in obestatin as compared to negative subjects. Ghrelin/obestatin ratio positively correlated with weight, body mass index, waist, glucose, insulin, HOMA-IR, leptin, cholesterol, triglycerides, low density cholesterol and also with H. pylori antigen in the same group.

CONCLUSIONS

It can be concluded that ghrelin, obestatin, and leptin are affected by presence of H. pylori seropositivity in obese subjects. The higher ghrelin levels and ghrelin/obestatin ratio with lowered obestatin could be considered as a gastro-protective effect against inflammation induced by H. pylori.

Enteroendocrine cells-sensory sentinels of the intestinal environment and orchestrators of mucosal immunity

The intestinal epithelium must balance efficient absorption of nutrients with partitioning commensals and pathogens from the bodies' largest immune system. If this crucial barrier fails, inappropriate immune responses can result in inflammatory bowel disease or chronic infection. Enteroendocrine cells represent 1% of this epithelium and have classically been studied for their detection of nutrients and release of peptide hormones to mediate digestion. Intriguingly, enteroendocrine cells are the key sensors of microbial metabolites, can release cytokines in response to pathogen associated molecules and peptide hormone receptors are expressed on numerous intestinal immune cells; thus enteroendocrine cells are uniquely equipped to be crucial and novel orchestrators of intestinal inflammation. In this review, we introduce enteroendocrine chemosensory roles, summarize studies correlating enteroendocrine perturbations with intestinal inflammation and describe the mechanistic interactions by which enteroendocrine and mucosal immune cells interact during disease; highlighting this immunoendocrine axis as a key aspect of innate immunity.

Helicobacter pylori Infection in Children: Nutritional Status and Associations with Serum Leptin, Ghrelin, and IGF-1 Levels

BACKGROUND

Helicobacter pylori is associated with gastrointestinal diseases such as gastritis, peptic ulcers, malignancy and lymphoma, and extra-gastrointestinal conditions. H. pylori infection is negatively associated with children's growth. Chronic inflammation of the stomach that results in the loss of appetite and, dysregulation of neuroendocrine hormones such as leptin, and ghrelin are the probable reasons of this negative association. The objective of this study is to determine the serum levels of leptin, ghrelin, and IGF-1 in H. pylori-infected children and their relations with growth.

MATERIALS AND METHODS

A hundred and sixty-one school children aged between 6 and 14 years were selected randomly from five primary schools representing a cross section of population. Demographic and sociocultural characteristics, and anthropometric measurements were recorded. Serum H. pylori IgG, insulin-like growth factor-1, leptin, and ghrelin levels were measured in all children. The children were grouped according to the nutritional status and Helicobacter pylori seropositivity. Nutritional indices were compared among groups in association with serum leptin, ghrelin, and insulin-like growth factor-1 levels.

RESULTS

H. pylori IgG positivity was found in 34.2%, and 14.9% of children were malnourished. H. pylori seropositivity was significantly higher in older ages (10.32 ± 2.26 vs 9.53 ± 2.36 years, p = .036), and body weight and height Z scores were significantly lower in H. pylori-seropositive children (-0.33 ± 1.08 vs 0.04 ± 1.26, p = .044 and 0.13 ± 0.92 vs 0.23 ± 0.91, p = .018 respectively). H. pylori seropositivity was found to be an independent risk factor for shorter body height (p = .01). Serum leptin, ghrelin, and IGF-1 levels were not associated with H. pylori IgG seropositivity (0.35 vs 0.55 ng/mL, p = .3; 3267.4 ± 753.0 vs 2808.3 ± 911.4 pg/mL, p = .06; 470 ± 176 vs 521 ± 179 ng/mL, p = .32, respectively).

CONCLUSIONS

Children infected with H. pylori are prone to short stature. This effect seems to be independent of neuroendocrine hormones.

Increase in plasma acyl ghrelin levels is associated with abatement of dyspepsia following Helicobacter pylori eradication

BACKGROUND

Ghrelin has been indicated as one of the etiological factors in functional dyspepsia (FD).

METHODS

We analyzed 179 patients with FD (based on the Rome III criteria) and 103 asymptomatic healthy individuals (controls) who had undergone endoscopy at Seoul National University Bundang Hospital from February 2011 to June 2014. FD patients were classified into three groups by means of a self-reported questionnaire: patients with postprandial distress syndrome (PDS; n = 49), patients with epigastric pain syndrome (EPS; n = 45), and patients with a combination of these two types (mixed group; n = 85). The fasting blood levels of acyl ghrelin and desacyl ghrelin and messenger RNA (mRNA) expression of preproghrelin in the fundic mucosa were measured by ELISAs and reverse transcription quantitative real-time PCR, respectively. One year after participant enrollment, they were measured again in 79 participants and the changes in the values were compared according to Helicobacter pylori eradication or symptom response.

RESULTS

Plasma acyl ghrelin level was lower in the PDS group than in the control and EPS groups (control group 14.1 fmol/mL, PDS group 8.9 fmol/mL, EPS group 13.8 fmol/mL, mixed group 11.3 fmol/mL; P = 0.003 and P = 0.012, respectively). One year after the eradication of H. pylori, plasma acyl ghrelin level was increased and gastric preproghrelin mRNA expression was upregulated (P = 0.004 and P < 0.001, respectively). Patients with abatement of symptoms demonstrated an increase in plasma acyl ghrelin level (from 11.51 to 21.00 fmol/L, P = 0.040).

CONCLUSIONS

Our results suggest that plasma acyl ghrelin plays a role in the development of PDS. H. pylori eradication upregulates preproghrelin mRNA expression and increases plasma acyl ghrelin level, contributing to the abatement of PDS symptoms.

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.

Implication of Cytotoxic Helicobacter pylori Infection in Autoimmune Diabetes

Background. Type 1 diabetes (T1D) and type 2 diabetes (T2D) have been linked to Helicobacter pylori infection, although results are conflicting. No previous study addressed a possible link between H. pylori infection and latent autoimmune diabetes in adults (LADA). In this study, a correlation among H. pylori infection and the risk of autoimmune diabetes in comparison with T2D was investigated. Methods. Sera from 234 LADA patients, 105 patients with late-onset T1D, and 156 patients with T2D were analyzed for anti-H. pylori and the cytotoxin-associated antigen (CagA) IgG antibodies. Results. H. pylori seroprevalence was comparable in LADA (52%), late-onset T1D (45%), and T2D (49%) with no gender differences. The seroprevalence of CagA IgG was significantly higher in autoimmune diabetes (late-onset T1D: 45%, LADA: 40%) compared to T2D (25%; p < 0.028). Conclusions. Although H. pylori seroprevalence was similar in LADA, T1D, and T2D, anti-CagA positivity was significantly increased among patients with autoimmune diabetes, suggesting that more virulent H. pylori strains might be a trigger for immune mechanisms involved in their pathogenesis.

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

BACKGROUND

Recently, publications in adults and children have documented a potential role of Helicobacter pylori (H. pylori) in decreasing the likelihood of obesity. The present study compares the prevalence of H. pylori colonization between obese (body mass index [BMI] ≥ 95th percentile) and healthy weight (BMI ≥ 5th to <85th percentiles) children seen at an inner city medical center in the United States.

METHODS

This retrospective study reviewed clinical features, BMI, and gastric histology of consecutive children aged 1-18 years undergoing an esophagogastroduodenoscopy. BMI percentile was calculated for age and gender. Helicobacter pylori colonization was determined by histopathologic identification of the organism. Multiple logistic regression was employed to measure the association between BMI and H. pylori colonization, controlling for baseline age, gender, and presenting symptoms.

RESULTS

Among 340 patients (51.5% female, mean age of 10.5 ± 4.7 years), 98 (29%) were obese and 173 (51%) were healthy weight. The H. pylori colonization rate of the entire cohort was 18.5% (95% CI = 14.7-23.0%). Among obese children, 10% had H. pylori colonization compared to 21% of the healthy weight children (RR = 2.1, 95% CI = 1.1-4.0). Conversely, 39% of noncolonized children, but only 21% of the infected children, were obese (RR = 1.8, 95% CI = 1.1-3.3). Multivariate analysis revealed that being colonized with H. pylori is associated with a 50% reduction in the odds of being obese (adjusted OR = 0.5, 95% CI = 0.2-1.0).

CONCLUSIONS

Our findings in a North American cohort are in agreement with studies from Asia and Europe suggesting that H. pylori infection decreases the prevalence of obesity in children. Further work to characterize the extent and nature of this relationship is warranted.

Obesity and related risk factors in gastric cardia adenocarcinoma

Over recent decades, the incidence of cancers of the gastroesophageal junction, including gastric cardia tumors, has increased markedly. This is a trend that has been well documented, especially in studies from the USA and northern Europe that have also demonstrated a concomitant rise in the ratio of cardia to distal gastric cancers. The rise in the prevalence of gastric cardia adenocarcinoma has been paralleled by the worldwide obesity epidemic, with almost all epidemiological studies reporting increased body mass index and obesity increase the risk of cardia cancer development. However, the strength of this association is less marked than the link between obesity and esophageal adenocarcinoma, and the mechanisms remain poorly understood. Other possible confounders of the relationship between obesity and cardia cancer include the decline in Helicobacter pylori infection and the widespread use of proton pump inhibitors, although these have rarely been controlled for in case-control and cohort studies investigating associations between obesity and cardia cancer. We review these epidemiological trends and discuss proposed mechanisms for the association, drawing attention to controversies over the difficulty of defining cardia cancer. The relative paucity of high-quality epidemiological studies from other regions of the world should prompt further investigation of this issue, especially in populations undergoing rapid socioeconomic change.

Helicobacter pylori infection and insulin resistance in diabetic and nondiabetic population

Helicobacter pylori (HP) is a common worldwide infection with known gastrointestinal and nongastrointestinal complications. One of the gastrointestinal side effects posed for this organism is its role in diabetes and increased insulin resistance. The aim of this study was to evaluate the association between HP and insulin resistance in type 2 diabetic patients and nondiabetics. This cross-sectional study was carried out from May to December 2013 on 211 diabetic patients referred to diabetes clinic of Shahid Beheshti Hospital of Qom and 218 patients without diabetes. HP was evaluated using serology method and insulin resistance was calculated using HOMA-IR. The prevalence of H. pylori infection was 55.8% and 44.2% in diabetics and nondiabetics (P = 0.001). The study population was divided into two HP positive and negative groups. Among nondiabetics, insulin resistance degree was 3.01 ± 2.12 and 2.74 ± 2.18 in HP+ and HP- patients, respectively (P = 0.704). Oppositely, insulin resistance was significantly higher in diabetic HP+ patients rather than seronegative ones (4.484 ± 2.781 versus 3.160 ± 2.327, P = 0.013). In diabetic patients, in addition to higher prevalence of HP, it causes a higher degree of insulin resistance.

Helicobacter pylori infection and diabetes: Is it a myth or fact?

Helicobacter pylori (H. pylori) is one of the most common human bacterial pathogens, and infection causes a wide array of gastric disorders, including simple gastritis, peptic ulcers and gastric malignancies. Gastrointestinal inflammation caused by H. pylori can influence the absorption of glucose and lipids, which are also abnormal in diabetes mellitus. Type 2 diabetes mellitus (T2DM), formerly known as non-insulin-dependent diabetes mellitus or adult-onset diabetes, is a metabolic disorder that is characterized by high levels of blood glucose resulting from insulin resistance and relative insulin deficiency. It is an emerging pandemic and is rapidly becoming a serious threat to public health. Emerging data now indicate a strong relationship between H. pylori infection and the incidence of T2DM. The mechanisms underlying the pathogenesis of diabetes are complex, involving insulin resistance, chronic inflammation, insulin secretion deficiency as a result of pancreas β-cell dysfunction, glucotoxicity, and lipotoxicity. H. pylori infection is known to be involved in the pathogenesis of insulin resistance, and the growing awareness of its role in diabetes is important for the early detection of glucose dysregulation and prevention of T2DM in high-risk communities. This review probes the possible relationship between H. pylori and diabetes according to epidemiological surveys and discusses putative mechanisms underlying this correlation.

Digestive function of the stomach

The core function of the human stomach is as an aid to digestion. The four key components of gastric digestive function are its function as a reservoir, acid secretion, enzyme secretion and its role in gastrointestinal motility. The reservoir capacity of the stomach allows it to increase its volume significantly while internal pressure increases only slightly. Acid secretion is a very important non-immunological defence against invading pathogens as well as being an important mechanism for vertebrates to have more complex diets. Stimulation of acid secretion involves the translocation of H+/K+-ATPases to the apical membrane of the parietal cell. The stomach is also an important endocrine organ producing an array of peptide hormones important for both enteric and non-enteric physiology including ghrelin and leptin. In addition to the reservoir function, the stomach also plays an important motility role as a pump, which anatomically is provided by the distal two thirds of the corpus, the antrum and the pylorus. This article examines those four functions and the role that they play in normal physiologic function and examines how they may play a role in pathologic states.

Scintigraphic methods to evaluate alterations of gastric and esophageal functions in female obesity

OBJECTIVE

Altered gastrointestinal function has frequently been observed in obese patients. The aim of this study was to investigate the frequency of gastro-esophageal reflux (GER) and to determine the alterations of gastric emptying and esophageal transit by scintigraphic methods in obese patients.

METHODS

Scintigraphic studies of 50 obese female non-diabetic patients who had not received any treatment for weight control were retrospectively reviewed. Mean Body Mass Index (BMI) was 34.96±3.04 kg/m(2) (range:32-39 kg/m(2)). All subjects were submitted to scintigraphic evaluation of esophageal transit, gastro-esophageal reflux, gastric emptying and presence of Helicobacter pylori infection. The data of obese patients were compared with those of sex-age matched 30 non-obese cases who were selected from our clinical archive.

RESULTS

In obese group, seventeen (34%) patients were found to be GER positive scintigraphically; mean gastric emptying time (t½) was 59.18±30.8 min and the mean esophageal transit time was 8.9±7.2 s. Frequency of positive GER scintigraphy and the mean value of esophageal transit time were significantly higher in obese patients than non-obese control subjects. Gastric emptying time and esophageal transit time values were significantly longer in GER positive obese patients than GER negative ones. There was no statistically significant difference in the frequency of positive C14 urea breath test between obese and non-obese subjects and there were also no statistically significant correlations between BMI, GER, esophageal transit time and gastric emptying time.

CONCLUSION

In our study, 42 of the 50 obese patients had esophago-gastric motility alterations. The significance of these alterations in obesity is not fully understood, but it is believed that these changes could be because of potential contributing factors in the development or maintenance of obesity or changes in eating habits.

CONFLICT OF INTEREST

None declared.

Helicobacter pylori infection associates with a mucosal downregulation of ghrelin, negative regulator of Th1-cell responses

BACKGROUND

Helicobacter pylori (Hp)-related gastritis is characterized by a predominant T helper (Th)1/Th17 cell immunity. Ghrelin (GR) has immunoregulatory properties and inhibits experimental Th cell-dependent pathology.

AIMS

To evaluate whether Hp infection associates with changes in GR expression and whether GR negatively regulates Th1/Th17 cytokines during Hp infection.

METHODS

GR expression was evaluated by real-time PCR in gastric biopsies taken from Hp-infected and Hp-uninfected patients and in gastric biopsies of Hp-negative subjects cultured with or without H. pylori culture supernatant. To examine whether GR regulates Hp-induced cytokine production, H. pylori-infected gastric biopsies were stimulated with GR, and interleukin (IL)-12, interferon (IFN)-γ and IL-4 transcripts were evaluated by real-time PCR. IL-12 and IFN-γ were also analyzed in lamina propria mononuclear cells (LPMCs) extracted from Hp-infected gastric biopsies and cultured with GR.

RESULTS

GR RNA transcripts were reduced in biopsies from Hp-infected patients. Treatment of Hp-negative gastric biopsies with Hp culture supernatant reduced GR RNA expression. GR dose-dependently inhibited RNA expression of IL-12 and IFN-γ but not IL-4 in ex vivo cultures of mucosal explants and in cultures of gastric LPMCs from Hp-positive patients.

CONCLUSIONS

GR is downregulated in the gastric mucosa of H. pylori-infected patients. Such a defect could contribute to sustain the ongoing Th1-cell response.

Gastric acid, calcium absorption, and their impact on bone health

Calcium balance is essential for a multitude of physiological processes, ranging from cell signaling to maintenance of bone health. Adequate intestinal absorption of calcium is a major factor for maintaining systemic calcium homeostasis. Recent observations indicate that a reduction of gastric acidity may impair effective calcium uptake through the intestine. This article reviews the physiology of gastric acid secretion, intestinal calcium absorption, and their respective neuroendocrine regulation and explores the physiological basis of a potential link between these individual systems.

Serum ghrelin is inversely associated with risk of subsequent oesophageal squamous cell carcinoma

BACKGROUND

Gastric atrophy, as determined by a low serum pepsinogen I:II ratio, may be associated with an increased risk of oesophageal squamous cell carcinoma (OSCC). Ghrelin, a hormone which, is also produced in the gastric fundic glands may be a marker of gastric atrophy, but its association with OSCC is not known.

METHODS

To examine the relationship between baseline serum ghrelin concentration and subsequent risk of OSCC, the authors conducted a nested case-control study within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) study. 82 cases of OSCC were matched (1:1) by age and date of blood draw to controls from the ATBC study. Serum ghrelin was measured by radioimmunoassay. ORs and 95% CIs were calculated using conditional logistic regression with adjustment for potential confounders.

RESULTS

For individuals in the lowest quartile of serum ghrelin, compared to those in the highest, the multivariate OR of subsequent OSCC was 6.83 (95% CI 1.46 to 31.84). These associations were dose dependent (p value for trend =0.005 for both), and independent of the effects of low pepsinogen I:II ratio and Helicobacter pylori infection. The significance of these associations remained even for individuals developing OSCC up to 10 years after baseline ghrelin measurement, although they become attenuated after 10 years.

CONCLUSION

Lower baseline concentrations of serum ghrelin were associated with an increase in risk of OSCC. Further studies are needed to confirm this finding in other populations and to explore the role of ghrelin in the aetiology of OSCC.

Correlation between Helicobacter pylori infection and hemoglobin A1c expression

Helicobacter pylori (H. pylori) is a gram-negative bacterium that is closely related with the pathogenesis of chronic gastritis, peptic ulcer, gastric carcinoma as well as many extra-gastrointestinal tract diseases such as coronary heart disease, iron deficiency anemia, idiopathic thrombocytopenic purpura, and diabetes mellitus (DM). Hemoglobin A1c (HbA1c) level is useful in diagnosing and monitoring DM. Recent studies showed that H. pylori is involved in the up-regulation of HbA1c level in DM patients through modulating the expression of leptin and ghrelin, whose interactions affect obesity, insulin sensitivity, glucose homeostasis and DM. Further studies on the association between H. pylori infection and HbA1c will certainly provide new prospects for early diagnosis and treatment of H. pylori-related DM and its complications.

Ghrelin - a pleiotropic hormone secreted from endocrine x/a-like cells of the stomach

The gastric X/A-like endocrine cell receives growing attention due to its peptide products with ghrelin being the best characterized. This peptide hormone was identified a decade ago as a stimulator of food intake and to date remains the only known peripherally produced and centrally acting orexigenic hormone. In addition, subsequent studies identified numerous other functions of this peptide including the stimulation of gastrointestinal motility, the maintenance of energy homeostasis and an impact on reproduction. Moreover, ghrelin is also involved in the response to stress and assumed to play a role in coping functions and exert a modulatory action on immune pathways. Our knowledge on the regulation of ghrelin has markedly advanced during the past years by the identification of the ghrelin acylating enzyme, ghrelin-O-acyltransferase, and by the description of changes in expression, activation, and release under different metabolic as well as physically and psychically challenging conditions. However, our insight on regulatory processes of ghrelin at the cellular and subcellular levels is still very limited and warrants further investigation.

Role of SST, CORT and ghrelin and its receptors at the endocrine pancreas

Somatostatin (SST), cortistatin (CORT), and its receptors (sst1-5), and ghrelin and its receptors (GHS-R) are two highly interrelated neuropeptide systems with a broad range of overlapping biological actions at central, cardiovascular, and immune levels among others. Besides their potent regulatory role on GH release, its endocrine actions are highlighted by SST/CORT and ghrelin influence on insulin secretion, glucose homeostasis, and insulin resistance. Interestingly, most components of these systems are expressed at the endocrine pancreas and are actively involved in the modulation of pancreatic islet function and, consequently influence glucose homeostasis. In addition, some of them also participate in islet survival and regeneration. Furthermore, under severe metabolic condition as well as in endocrine pathologies, their expression profile is severely deregulated. These findings suggest that SST/CORT and ghrelin systems could play a relevant role in pancreatic function under metabolic and endocrine pathologies. Accordingly, these systems have been therapeutically targeted for the prevention or amelioration of certain metabolic conditions (obesity) as well as for tumor growth inhibition and/or hormonal regulation in endocrine pathologies (neuroendocrine tumors). This review focuses on the interrelationship between SST/CORT and ghrelin systems and their role in severe metabolic conditions and some endocrine disorders.

Stress-related alterations of acyl and desacyl ghrelin circulating levels: mechanisms and functional implications

Ghrelin is the only known peripherally produced and centrally acting peptide hormone that stimulates food intake and digestive functions. Ghrelin circulates as acylated and desacylated forms and recently the acylating enzyme, ghrelin-O-acyltransferase (GOAT) and the de-acylating enzyme, thioesterase 1/lysophospholipase 1 have been identified adding new layers of complexity to the regulation of ghrelin. Stress is known to alter gastrointestinal motility and food intake and was recently shown to modify circulating ghrelin and GOAT levels with differential responses related to the type of stressors including a reduction induced by physical stressors (abdominal surgery and immunological/endotoxin injection, exercise) and elevation by metabolic (cold exposure, acute fasting and caloric restriction) and psychological stressors. However, the pathways underlying the alterations of ghrelin under these various stress conditions are still largely to be defined and may relate to stress-associated autonomic changes. There is evidence that alterations of circulating ghrelin may contribute to the neuroendocrine and behavioral responses along with sustaining the energetic requirement needed upon repeated exposure to stressors. A better understanding of these mechanisms will allow targeting components of ghrelin signaling that may improve food intake and gastric motility alterations induced by stress.

Helicobacter pylori and nonmalignant diseases

Research published over the past year has documented the continued decline of Helicobacter pylori-related peptic ulcer disease and increased recognition of non-H. pylori, non-steroidal anti-inflammatory drugs ulcer disease--idiopathic ulcers. Despite reduced prevalence of uncomplicated PUD, rates of ulcer complications and associated mortality remain stubbornly high. The role of H. pylori in functional dyspepsia is unclear, with some authors considering H. pylori-associated nonulcer dyspepsia a distinct organic entity. There is increasing acceptance of an inverse relationship between H. pylori and gastroesophageal reflux disease (GERD), but little understanding of how GERD might be more common/severe in H. pylori-negative subjects. Research has focused on factors such as different H. pylori phenotypes, weight gain after H. pylori eradication, and effects on hormones such as ghrelin that control appetite.