Plasma ghrelin following cure of Helicobacter pylori

Helicobacter pylori and nonmalignant diseases

This paper reviews the new literature from the past year on the association between colonization with Helicobacter pylori and non-malignant disease of the upper gastrointestinal tract. This issue has, in the past year, remained a topic of wide research interest yielding many important new data. These data show that H. pylori eradication is the most effective therapy for peptic ulcer disease, but that a considerable proportion of ulcer patients remain to have dyspeptic symptoms. The discussion on the interaction between H. pylori and NSAID use in the etiology of ulcer disease has not yet been settled. Several studies, both from Asia and Europe, now reported that H. pylori eradication has a minimal effect on the primary prevention of ulcer disease in NSAID users, but eradication appears of relevance for the secondary prevention of ulcer disease in addition to proton pump inhibitor maintenance therapy. Various studies brought further support for the hypothesis that H. pylori eradication is of some benefit for patients with non-ulcer dyspepsia, although the effects are limited. The prevalence of H. pylori is lower among GERD patients than among controls, but H. pylori eradication has not been consistently shown to increase the risk for the newly development of GERD in an individual subject undergoing H. pylori eradication. The discussion on H. pylori and GERD should not preclude us from treating H. pylori-infected patients for accepted clinical indications. In patients using proton pump inhibitors for GERD, H. pylori eradication leads to a resolution of their corpus-predominant pangastritis, without impairing the efficacy of PPI therapy.

Helicobacter pylori and extragastric diseases--other Helicobacters

Reports on Helicobacter pylori and extragastric diseases have almost doubled this year compared with last year, bearing witness to the persistent scientific interest in this branch of Helicobacter-related pathology. Data belong increasingly to the area of vascular medicine, as well as hematology, dermatology, pediatrics and other fields. Unfortunately, these studies show overall controversial results, due to the impact of several confounding factors, and to the difficulty of recruiting homogeneous patient populations. Furthermore, many studies continue to be conducted on Helicobacter species other than H. pylori, focusing on animal models of gastroenterological illnesses which may retain strong similarities with human diseases. In this paper, taxonomy, detection and characterisation of Helicobacter spp. will be reviewed, together with the most important data issued this year on other Helicobacters and animal models.

Ghrelin, appetite, and gastric motility: the emerging role of the stomach as an endocrine organ

Recent progress in the field of energy homeostasis was triggered by the discovery of adipocyte hormone leptin and revealed a complex regulatory neuroendocrine network. A late addition is the novel stomach hormone ghrelin, which is an endogenous agonist at the growth hormone secretagogne receptor and is the motilin-related family of regulatory peptides. In addition to its ability to stimulate GH secretion and gastric motility, ghrelin stimulates appetite and induces a positive energy balance leading to body weight gain. Leptin and ghrelin are complementary, yet antagonistic, signals reflecting acute and chronic changes in energy balance, the effects of which are mediated by hypothalamic neuropeptides such as neuropeptide Y and agouti-related peptide. Endocrine and vagal afferent pathways are involved in these actions of ghrelin and leptin. Ghrelin is a novel neuroendocrine signal possessing a wide spectrum of biological activities that illustrates the importance of the stomach in providing input into the brain. Defective ghrelin signaling from the stomach could contribute to abnormalities in energy balance, growth, and associated gastrointestinal and neuroendocrine functions.

The implications of Helicobacter pylori infection for gastroesophageal reflux disease: studies presented at Digestive Disease Week 2003

The relationship between Helicobacter pylori infection and gastroesophageal reflux disease (GERD) remains controversial. Over 20 studies presented at the 2003 Digestive Disease Week meeting examined the implications of H. pylori infection for GERD. Although the findings were not uniform, most of the studies presented indicated a negative association between the presence of H. pylori and the presence of GERD symptoms, signs, or complications. In addition, eradication of H. pylori infection was related to the emergence of GERD and its complications. However, most studies favored a role for H. pylori rather than GERD in the development of pathologic changes in the gastric cardia. Finally, a few studies suggested the intriguing possibility that the modulation of GERD by H. pylori could be through the effects of H. pylori eradication on weight gain.

Helicobacter pylori persistence: biology and disease

Helicobacter pylori are bacteria that have coevolved with humans to be transmitted from person to person and to persistently colonize the stomach. Their population structure is a model for the ecology of the indigenous microbiota. A well-choreographed equilibrium between bacterial effectors and host responses permits microbial persistence and health of the host but confers risk of serious diseases, including peptic ulceration and gastric neoplasia.

Helicobacter pylori persistence: biology and disease

Helicobacter pylori are bacteria that have coevolved with humans to be transmitted from person to person and to persistently colonize the stomach. Their population structure is a model for the ecology of the indigenous microbiota. A well-choreographed equilibrium between bacterial effectors and host responses permits microbial persistence and health of the host but confers risk of serious diseases, including peptic ulceration and gastric neoplasia.

Helicobacter pylori infection modifies gastric and plasma ghrelin dynamics in Mongolian gerbils

BACKGROUND

and aim: Although ghrelin, a novel growth hormone releasing peptide localised mainly in the gastric fundus, is reported not only to accelerate food passage and gastrointestinal motility but also to affect appetite and weight control, regulation of gastric ghrelin secretion under the conditions of gastric Helicobacter pylori infection is unknown. The present study was designed to investigate plasma and gastric ghrelin levels in Mongolian gerbils with H pylori colonisation of the gastric mucosa.

METHODS

Gerbils orally inoculated with H pylori were examined after inoculation. To examine preproghrelin mRNA expression in the gastric mucosa, cDNA encoding the gerbil preproghrelin and glyceraldehyde-3-phosphate dehydrogenase homologue was isolated and a quantitative reverse transcription-polymerase chain reaction system was established.

RESULTS

In gerbils showing H pylori colonisation (H pylori group), expression of preproghrelin mRNA and total ghrelin levels were significantly decreased 17 and 23 weeks later (p<0.01). Although the number of ghrelin immunoreactive cells decreased as the stomach weight increased, the gastric contents of total and active ghrelin in this group were the same as those in controls. Gastric myeloperoxidase activity showed a positive correlation with plasma ghrelin levels. On the other hand, at 17 weeks, plasma ghrelin levels were significantly increased in the H pylori group (p<0.05), suggesting a compensatory increase in secretion of the peptide at this time point.

CONCLUSION

The present experimental study demonstrated that gastric and plasma ghrelin dynamics are altered in response to H pylori infection.

Ghrelin for the gastroenterologist: history and potential

Ghrelin, a novel 28-amino acid orexigenic peptide discovered in 1999, has given us further insights into the control of energy homeostasis and growth hormone secretion. As a natural endogenous ligand of the growth hormone secretagogue receptor, it potently stimulates growth hormone release but is also implicated in many other homeostatic mechanisms. Released from the stomach, it stimulates lactotroph and corticotroph secretion, increases appetite and adiposity, has beneficial hemodynamic effects, has prokinetic and gastric acid secretory functions in the stomach, and may even be implicated in sleep. As advances in the understanding of appetite and obesity are made, it is timely to review the possibly central role of ghrelin in these physiological and pathophysiological states. This review will discuss the recent literature concerning this exciting novel neuropeptide and discuss the possible therapeutic possibilities it may open up to us.