Influence of Helicobacter pylori infection on gastric acid secretion in pre-school Bangladeshi children

Review of paediatric gastrointestinal physiology relevant to the absorption of orally administered medicines

Despite much progress in regulations to improve paediatric drug development, there remains a significant need to develop better medications for children. For the design of oral dosage forms, a detailed understanding of the specific gastrointestinal (GI) conditions in children of different age categories and how they differ from GI conditions in adults is essential. Several review articles have been published addressing the ontogeny of GI characteristics, including luminal conditions in the GI tract of children. However, the data reported in most of these reviews are of limited quality because (1) information was cited from very old publications and sometimes low quality sources, (2) data gaps in the original data were filled with textbook knowledge, (3) data obtained on healthy and sick children were mixed, (4) average data obtained on groups of patients were mixed with data obtained on individual patients, and (5) results obtained using investigative techniques that may have altered the outcome of the respective studies were considered. Consequently, many of these reviews draw conclusions that may be incorrect. The aim of the present review was to provide a comprehensive and updated overview of the available original data on the ontogeny of GI luminal conditions relevant to oral drug absorption in the paediatric population. To this end, the PubMed and Web of Science metadatabases were searched for appropriate studies that examined age-related conditions in the oral cavity, esophagus, stomach, small intestine, and colon. Maturation was observed for several GI parameters, and corresponding data sets were identified for each paediatric age group. However, it also became clear that the ontogeny of several GI traits in the paediatric population is not yet known. The review article provides a robust and valuable data set for the development of paediatric in vitro and in silico biopharmaceutical tools to support the development of age-appropriate dosage forms. In addition, it provides important information on existing data gaps and should provide impetus for further systematic and well-designed in vivo studies on GI physiology in children of specific age groups in order to close existing knowledge gaps and to sustainably improve oral drug therapy in children.

Helicobacter pylori infection and hypochlorhydria in Zambian adults and children: A secondary data analysis

Background

Hypochlorhydria (gastric pH >4) increases susceptibility to diarrhoea, iron deficiency, and gastric cancer. We sought to clarify the prevalence of this condition and its predisposing factors in Zambia by pooling data from previous studies conducted in hospital and community settings.

Methods

Gastric pH was measured in participants from five separate studies by collecting gastric aspirate from fasted adults and children under 3 years of age undergoing gastroscopy. Gastric pH was correlated with serological testing for Human Immunodeficiency Virus (HIV) and Helicobacter pylori (H. pylori) infections.

Results

We studied 597 individuals (487 adults and 110 children). Hypochlorhydria was present in 53% of adults and 31% of children. HIV infection was detected in 41% of adults and 11% of children. H. pylori serology was available for 366 individuals: 93% of adults and 6% of children were seropositive. In univariate analysis, hypochlorhydria was significantly associated with HIV seropositivity (OR 1.7; 95% CI 1.2–2.4; p = 0.004) and H. pylori antibody seropositivity (OR 4.9; 95% CI 2.8–8.6; p<0.0001), and with advancing age in HIV negative individuals (p = 0.0001). In multivariable analysis, only H. pylori was associated with hypochlorhydria (OR 4.0; 95% CI 2.2–7.2; p<0.0001) while excluding possible exposure to proton pump inhibitors.

Conclusions

Hypochlorhydria is common in our population, with H. pylori being the dominant factor. Only young HIV seronegative individuals had a low prevalence of hypochlorhydria. This may have implications for the risk of other health conditions including gastric cancer.

How did the ancient bacterium, Helicobacter pylori, cause an epidemic of chronic duodenal ulceration?

The association of Helicobacter pylori with chronic duodenal ulceration was a seminal observation in the short history of gastroenterology. However, H. pylori is now known to be an ancient bacterium, whereas there is persuasive evidence that the epidemic of duodenal ulceration began in the second half of the 19th century and continued into the second half of the 20th century. Possible explanations for the epidemic include genomic changes in the organism and environmental or other influences on the human host. While genomic changes resulted in the appearance of virulence factors, these seem likely to have appeared thousands of years ago with minimal effects on gastritis because of coexisting suppression of gastric immunity. In contrast, the emergence of duodenal ulceration is best explained by a change in the pattern of gastritis from inflammation involving the antrum and body in most individuals to a significant minority (10-20%) with antral gastritis but with relative sparing of the body of the stomach. In the latter group, the increase in serum gastrin (particularly G17) associated with antral gastritis had trophic effects on gastric parietal cells with an increase in the parietal cell mass and hypersecretion of gastric acid. Hypersecretion of acid is seen as the major risk factor for duodenal ulceration with significant contributions from environmental factors including smoking and use of nonsteroidal, anti-inflammatory drugs. Host factors favoring changes in the pattern of gastritis include delayed acquisition of infection and improved nutrition; both with enhancing effects on mucosal immunity.

Rise and fall of peptic ulceration: A disease of civilization?

Humans and Helicobacter pylori have evolved and adapted over tens of thousands of years. Yet peptic ulcer disease appeared to be rare prior to the 19th century. The prevalence of peptic ulcer disease increased between 1850 and 1900 and culminated in a cohort at high risk that was born at the end of the 19th century. This coincided with the provision of safe water and improvements in sanitation and personal hygiene. One hypothesis for the emergence of peptic ulcer disease focuses on the rate of development of atrophic gastritis induced by H. pylori. The hypothesis developed in this article focuses on delay in the age of acquisition of H. pylori to a time when immune and inflammatory responses to the infection were more mature. Whereas the acquisition of H. pylori in infancy usually resulted in mild pangastritis, hypochlorhydria, and a low risk for peptic ulcer disease, delayed acquisition could cause either more severe pangastritis (predisposing to gastric ulceration) or gastritis largely restricted to the antrum of the stomach (predisposing to duodenal ulceration). The decline in the prevalence of peptic ulcer disease over the past 100 years parallels the decline in the prevalence of H. pylori. The epidemic of ulcer disease in the first half of the 20th century seems likely to be an adverse effect of important public health measures undertaken in the latter half of the 19th century.

Hunger and microbiology: is a low gastric acid-induced bacterial overgrowth in the small intestine a contributor to malnutrition in developing countries?

Underproduction of hydrochloric acid into the stomach is frequently encountered in subjects from developing countries. We explore the hypothesis that hypochlorhydria compromises the gastric barrier and favours bacterial overgrowth in the proximal parts of the small intestine where nutrient absorption takes place. Food calories are thus deviated into bacterial metabolism. In addition to an adequate caloric supply, correcting hypochlorhydria might be needed to decrease childhood malnutrition.

Helicobacter pylori infection and its related factors in junior high school students in Nagano Prefecture, Japan

BACKGROUND

There have been few reports on Helicobacter pylori (H. pylori) infection in asymptomatic Japanese children and adolescents. We hypothesized that the prevalence of H. pylori infection is very low among Japanese children and that clinical variables such as serum pepsinogen and iron levels are associated with H. pylori infection.

MATERIALS AND METHODS

We conducted a cross-sectional analysis of a sample of 454 junior high school students aged 12-15 years in four areas in Nagano Prefecture. A commercial ELISA kit (E-plate Eiken H. pylori antibody) was used to measure IgG antibody against H. pylori. Serum pepsinogen and iron levels were also measured using standard methods. A urea breath test was performed for seropositive students.

RESULTS

The overall prevalence of H. pylori was 3.1% (14/454). There were no significant differences in H. pylori prevalence among mountain, rural, and urban areas. The mean level of both serum pepsinogen (PG I) and PG II was significantly increased in the seropositive subjects compared with the seronegative subjects. When the cutoff values for adults (PG I: 70 ng/mL and PG I/II ratio: 3) were used, 4 of 14 subjects had PG I ≤70 ng/mL and PG I/II ratio ≤3. The results of a logistic regression analysis showed that low serum iron levels were significantly associated with H. pylori infection (P=.02).

CONCLUSIONS

The prevalence of H. pylori infection is as low as 3% among junior high school students aged 12-15 years in Japan. The disappearance of H. pylori is accelerating in Japanese children.

Immunomodulatory Effect of H. Pylori CagA Genotype and Gastric Hormones On Gastric Versus Inflammatory Cells Fas Gene Expression in Iraqi Patients with Gastroduodenal Disorders

AIM:

To evaluate the Immunomodulatory effects of CagA expression; pepsinogen I, II & gastrin-17 on PMNs and lymphocytes Fas expression in inflammatory and gastric cells; demographic distribution of Fas molecule in gastric tissue and inflammatory cells.

METHODS:

Gastroduodenal biopsies were taken from 80 patients for histopathology and H. pylori diagnosis. Serum samples were used for evaluation of pepsinogen I (PGI); (PGII); gastrin-17 (G-17).

RESULTS:

Significant difference (p < 0.001) in lymphocytes & PMNs Fas expression; epithelial & lamina propria Fas localization among H. pylori associated gastric disorders. No correlation between grade of lymphocytes & PMNs Fas expression in gastric epithelia; lamina propria and types of gastric disorder. Significant difference (p < 0.001) in total gastric Fas expression, epithelial Fas; lamina propria and gastric gland Fas expression according to CagA, PGI; PGII; PGI/PGII; Gastrin-17. Total gastric Fas expression has significant correlation with CagA, PGII levels. Gastric epithelial and gastric lamina propria Fas expression have significant correlation with CagA, PGI; PGII levels. Significant difference (p < 0.001) was found in lymphocytes & PMNs Fas expression; epithelial & lamina propria localization of lymphocytes & PMNs Fas expression according to CagA, PGI; PGII; PGI/PGII; Gastrin-17. Lymphocytes Fas expression have correlation with PGI, PGII, PGI/PGII. PMNs Fas expression have correlation with PGI, PGII.

CONCLUSION:

Fas gene expression and localization on gastric and inflammatory cells affected directly by H. pylori CagA and indirectly by gastric hormones. This contributes to progression of various gastric disorders according to severity of CagA induced gastric pathology and gastric hormones disturbance throughout the course of infection and disease.

Association between Gastric pH and Helicobacter pylori Infection in Children

PURPOSE

To assess gastric pH and its relationship with urease-test positivity and histological findings in children with Helicobacter pylori infection.

METHODS

Fasting gastric juices and endoscopic antral biopsy specimens were collected from 562 children and subjected to the urease test and histopathological examination. The subjects were divided into 3 age groups: 0-4, 5-9, and 10-15 years. The histopathological grade was assessed using the Updated Sydney System, while the gastric juice pH was determined using a pH meter.

RESULTS

The median gastric juice pH did not differ significantly among the age groups (p=0.655). The proportion of individuals with gastric pH >4.0 was 1.3% in the 0-4 years group, 6.1% in the 5-9 years group, and 8.2% in 10-15 years (p=0.101). The proportions of moderate and severe chronic gastritis, active gastritis, and H. pylori infiltration increased with age (p<0.005). Urease-test positivity was higher in children with hypochlorhydria (77.8%) than in those with normal gastric pH (31.7%) (p<0.001). Chronic and active gastritis were more severe in the former than the latter (p<0.001), but the degree of H. pylori infiltration did not differ (20.9% vs. 38.9%; p=0.186).

CONCLUSION

Gastric pH while fasting is normal in most children regardless of age. Urease-test positivity may be related to hypochlorhydria in children, and hypochlorhydria is in turn related to H. pylori infection.