Plasma ghrelin following cure of Helicobacter pylori

Helicobacter pylori infection and endocrine disorders: Is there a link?

Helicobacter pylori (H pylori) infection is a leading world-wide infectious disease as it affects more than half of the world population and causes chronic gastritis, peptic ulcer disease and gastric malignancies. The infection elicits a chronic cellular inflammatory response in the gastric mucosa. However, the effects of this local inflammation may not be confined solely to the digestive tract but may spread to involve extra-intestinal tissues and/or organs. Indeed, H pylori infection has been epidemiologically linked to extra-digestive conditions and diseases. In this context, it has been speculated that H pylori infection may be responsible for various endocrine disorders, such as autoimmune thyroid diseases, diabetes mellitus, dyslipidemia, obesity, osteoporosis and primary hyperparathyroidism. This is a review of the relationship between H pylori infection and these endocrine disorders.

Helicobacter pylori in health and disease

Helicobacter pylori is highly adapted for colonization of the human stomach and is present in about half of the human population. When present, H pylori is usually the numerically dominant gastric microorganism. H pylori typically does not cause any adverse effects, but it is associated with an increased risk of noncardia gastric adenocarcinoma, gastric lymphoma, and peptic ulcer. Disorders such as esophageal diseases and childhood-onset asthma were recently reported to occur more frequently in individuals who lack H pylori than in H pylori-positive persons. In this review, we discuss biologic factors that allow H pylori to colonize the human stomach, mechanisms by which H pylori increases the risk of peptic ulcer disease and noncardia gastric adenocarcinoma, and potential benefits that H pylori might confer to humans.

The influence of the eradication of Helicobacter pylori on gastric ghrelin, appetite, and body mass index in patients with peptic ulcer disease

BACKGROUND AND AIM

Helicobacter pylori (H. pylori) infection has been known to influence the gastric leptin and ghrelin secretion, for which the exact pathogenic role has not been documented yet. This study was designed to investigate the influence of H. pylori eradication on plasma or gastric levels of ghrelin, body mass index (BMI), and resultant levels of appetite in patients with peptic ulcer disease.

METHODS

Twenty-two patients with H. pylori-associated active duodenal or gastric ulcer were treated with 7 weeks of antisecretory medication followed with 7 days of eradication regimen. The plasma and tissue ghrelin levels, tumor necrosis factor-alpha (TNF-alpha) mRNA, BMI, and appetite scale were checked before and after treatment. An additional endoscopic examination was conducted in 10 patients taking both ulcer treatment and H. pylori eradication.

RESULTS

Gastric ghrelin mRNA expression was significantly increased after either ulcer healing or H. pylori eradication, whereas gastric TNF-alpha mRNA expression was decreased after ulcer treatment and H. pylori eradication. In parallel with these changes, the visual analog scales for hunger and prospective food consumption were significantly increased after ulcer healing and H. pylori eradication. An increase in BMI was not statistically related to ulcer healing and H. pylori eradication therapy. In the subgroup analysis of 10 patients performed with additional endoscopic examination, ulcer treatment was associated with increased plasma ghrelin level and tissue ghrelin expression irrelevant to H. pylori eradication.

CONCLUSION

Restored tissue levels of ghrelin and improved status of appetite was achieved with gastric ulcer healing and H. pylori eradication.

Gastroesophageal reflux disease: an Asian perspective

The prevalence of gastroesophageal reflux disease (GERD) ranges from 2.5% to 7.1% in most population-based studies in Asia. There is evidence that GERD and its complications are rising, coinciding with a decline in Helicobacter pylori (H. pylori) infection. Asian GERD patients share similar risk factors and pathophysiological mechanisms with their Western counterparts. Possible causes for the lower prevalence of GERD include less obesity and hiatus hernia, a lesser degree of esophageal dysmotility, a high prevalence of virulent strains of H. pylori, and low awareness. Owing to the lack of precise translation for 'heartburn' in most Asian languages, reflux symptoms are often overlooked or misinterpreted as dyspepsia or chest pain. Furthermore, a symptom-based diagnosis with a therapeutic trial of the proton pump inhibitor (PPI) may be hampered by the high prevalence of H. pylori-related disease. The risk stratification for prompt endoscopy, use of a locally-validated, diagnostic symptom questionnaire, and response to H. pylori'test and treat' help improve the accuracy of the PPI test for diagnoses. PPI remain the gold standard treatment, and 'on-demand' PPI have been shown to be a cost-effective, long-term treatment. The clinical course of GERD is benign in most patients in Asia. The risk of progression from non-erosive reflux disease to erosive esophagitis is low, and treatment response to a conventional dose of PPI is generally higher. Although H. pylori eradication may lead to more resilient GERD in a subset of patients, the benefits of H. pylori eradication outweigh the risks, especially in Asian populations with a high incidence of gastric cancer.

Ghrelin and Helicobacter pylori infection

Ghrelin is primarily secreted from the stomach and has been implicated in the coordination of eating behavior and weight regulation. Ghrelin also plays an essential role in the mechanism of gastric mucosal defense. Thus, it is important to clarify which diseases primarily influence changes in plasma ghrelin concentrations. Helicobacter pylori (H pylori) infection is involved in the pathogenesis of gastritis, gastric and duodenal ulcer, gastric carcinoma, and mucosa-associated lymphoid tissue lymphoma. H pylori eradication is related to body weight change. Compared, H pylori infected and negative subjects with normal body mass index, plasma ghrelin concentration, gastric ghrelin mRNA, and the number of ghrelin producing cells in gastric mucosa are significantly lower in H pylori infected subjects than in H pylori-negative controls. Plasma ghrelin concentration decreases with the progression of gastric atrophy. Impaired gastric ghrelin production in association with atrophic gastritis induced by H pylori infection accounts for the decrease in plasma ghrelin concentration. However, the ratio of plasma acylated ghrelin to total ghrelin levels is higher in patients with chronic atrophic gastritis than in healthy subjects. This may result from the compensatory increase in plasma active ghrelin concentration in response to gastric atrophy. After H pylori eradication, gastric preproghrelin mRNA expression is increased nearly 4-fold in most cases. However, changes in plasma ghrelin concentrations before and after H pylori cure are not associated with the gastric ghrelin production. Plasma ghrelin changes are inversely correlated with both body weight change and initial plasma ghrelin levels.

Serum ghrelin levels in inflammatory bowel disease with relation to disease activity and nutritional status

Ghrelin possesses various biological activities -- it stimulates growth hormone (GH) release, plays a major role in energy metabolism, and is one of the hormones that affects body composition. It also plays a role in modulating immune response and inflammatory processes. In this study we aimed to determine whether serum ghrelin levels had correlation with markers associated with disease activation. We also investigated any probable relationship between serum ghrelin level and nutritional status. Serum levels of ghrelin and its relationship with disease activity and nutritional status were evaluated in 34 patients with ulcerative colitis (UC), 25 patients with Crohn's disease (CD), and 30 healthy controls. Serum ghrelin levels, serum IGF-1 and GH levels, and markers of disease activity (sedimentation, C-reactive protein, and fibrinogen) were measured in all subjects. Body composition and nutritional status was assessed by both direct (by anthropometry) and indirect (by bioimpedance) methods. Serum ghrelin levels were significantly higher in patients with active UC and CD than in those in remission (108 +/- 11 pg/ml vs. 71 +/- 13 pg/ml for UC patients, P < 0.001; 110 +/- 10 pg/ml vs. 75 +/- 15 pg/ml for CD patients, P < 0.001). Circulating ghrelin levels in UC and CD patients were positively correlated with sedimentation, fibrinogen and CRP and was negatively correlated with IGF-1, BMI, TSFT, MAC, fat mass (%), and fat free mass (%). This study demonstrates that patients with active IBD have higher serum ghrelin levels than patients in remission and high levels of circulating ghrelin correlate with the severity of disease and the activity markers. Ghrelin levels in inflammatory bowel disease (IBD) patients show an appositive correlation with IGF-1 and bioelectrical impedance analysis, body composition, and anthropometric assessments. Finally, we arrived at the conclusion that ghrelin level may be important in determination of the activity in IBD patients and evaluation of nutritional status.

Leptin and ghrelin in relation to Helicobacter pylori status in adult males

CONTEXT

Leptin and ghrelin, hormones involved in human energy homeostasis, are both produced in the stomach.

OBJECTIVE

We sought to determine whether the presence of Helicobacter pylori affects gastric and systemic levels of leptin and ghrelin.

DESIGN, SETTING, AND PATIENTS

We consecutively enrolled 256 patients referred for upper endoscopy at a Veterans Affairs outpatient endoscopy center.

OUTCOMES

We obtained fasting serum, fundic and antral biopsies, and gastric juice. Based on histological, biochemical, and serological assays, patients were categorized as H. pylori+ or H. pylori-. Leptin and total ghrelin levels in serum, gastric biopsies, and gastric juice were determined by specific ELISAs.

RESULTS

Of the 256 subjects, 120 were H. pylori+ and 96 were H. pylori-; 40 patients of indeterminate status were excluded. Serum and fundic leptin levels correlated with body mass index in the H. pylori+ (r = 0.35; P < 0.0001 and r = 0.35; P < 0.0001, respectively) and H. pylori- (r = 0.65; P < 0.0001 and r = 0.41; P < 0.0001, respectively) groups, but H. pylori+ subjects had significantly lower serum leptin levels [median 2.2 ng/ml (interquartile range 0.9-4.6) vs. 4.0 ng/ml (1.7-7.2); P = 0.0003]. Serum ghrelin levels were similar in the H. pylori+ and H. pylori- groups [median 1651 pg/ml (interquartile range 845-2247) vs. 1629 pg/ml (992-2886); P = 0.23]. H. pylori status did not significantly affect gastric biopsy leptin and ghrelin levels. Ghrelin levels in gastric juice varied over 4 log(10) (<80-776,000 pg/ml) and correlated with gastric juice pH in the H. pylori+ group (r = 0.68; P < 0.0001).

CONCLUSIONS

These findings provide evidence that H. pylori status affects leptin and ghrelin homeostasis, presumably via intragastric interactions.

Helicobacter pylori infection and the risk of Barrett's oesophagus: a community-based study

OBJECTIVE

Gastric colonisation with the Helicobacter pylori bacterium is a proposed protective factor against oesophageal adenocarcinoma, but its point of action is unknown. Its associations with Barrett's oesophagus, a metaplastic change that is a probable early event in the carcinogenesis of oesophageal adenocarcinoma, were evaluated

METHODS

A case-control study was carried out in the Kaiser Permanente Northern California population, a large health services delivery organisation. Persons with a new Barrett's oesophagus diagnosis (cases) were matched to subjects with gastro-oesophageal reflux disease (GORD) without Barrett's oesophagus and to population controls. Subjects completed direct in-person interviews and antibody testing for H pylori and its CagA (cytotoxin-associated gene product A) protein.

RESULTS

Serological data were available on 318 Barrett's oesophagus cases, 312 GORD patients and 299 population controls. Patients with Barrett's oesophagus were substantially less likely to have antibodies for H pylori (OR = 0.42, 95% CI 0.26 to 0.70) than population controls; this inverse association was stronger among those with lower body mass indexes (BMIs < 25, OR = 0.03, 95% CI 0.00 to 0.20) and those with CagA+ strains (OR = 0.08, 95% CI 0.02 to 0.35). The associations were diminished after adjustment for GORD symptoms. The H pylori status was not an independent risk factor for Barrett's oesophagus compared with the GORD controls.

CONCLUSIONS

Helicobacter pylori infection and CagA+ status were inversely associated with a new diagnosis of Barrett's oesophagus. The findings are consistent with the hypothesis that H pylori colonisation protects against Barrett's oesophagus and that the association may be at least partially mediated through GORD.

Ghrelin Levels in Gastric Mucosa before and after Eradication of Helicobacter pylori

BACKGROUND/AIMS

The relationship between Helicobacter pylori infection and ghrelin is controversial. We compared ghrelin levels in gastric mucosa and plasma between H. pylori-positive and -negative subjects, and between before and after H. pylori eradication.

METHODS

We compared the ghrelin levels in the antrum, body, and fundus between H. pylori-positive and -negative subjects; in stomach tissues between before and after H. pylori eradication; and in plasma and tissue in 10-person cohorts between before and after H. pylori eradication therapy. Body mass index, age, and sex were controlled for when comparing ghrelin levels.

RESULTS

Stomach ghrelin levels (in the antrum, body, and fundus) did not differ significantly between H. pylori-positive and -negative samples (p=0.095, 0.316, and 0.897, respectively), or between before and after H. pylori eradication (p=0.19, 0.178, and 0.513, respectively). In the ten-person cohort study, plasma ghrelin levels in the eight H. pylori-positive subjects were 2,260 pg/mL (range, 1,280-3,770 pg/mL) and 1,900 pg/mL (range, 1,350-5,200 pg/mL) before and after eradication therapy (p=0.871). Stomach ghrelin levels did not differ significantly in the eight H. pylori-positive subjects between before and after H. pylori eradication (p=0.732, 0.618, and 0.435 in the antrum, body, and fundus, respectively), or between six eradicated and two noneradicated subjects (p=0.071, 0.857, 0.429, and 0.857 in the antrum, body, fundus, and plasma, respectively).

CONCLUSIONS

These results show that H. pylori infection has no effect on stomach ghrelin levels and that eradication therapy does not influence plasma or tissue ghrelin levels.

The pathogenesis of Helicobacter pylori-induced gastro-duodenal diseases

Helicobacter pylori is the main cause of peptic ulceration, distal gastric adenocarcinoma, and gastric lymphoma. Only 15% of those colonized develop disease, and pathogenesis depends upon strain virulence, host genetic susceptibility, and environmental cofactors. Virulence factors include the cag pathogenicity island, which induces proinflammatory, pro-proliferative epithelial cell signaling; the cytotoxin VacA, which causes epithelial damage; and an adhesin, BabA. Host genetic polymorphisms that lead to high-level pro-inflammatory cytokine release in response to infection increase cancer risk. Pathogenesis is dependent upon inflammation, a Th-1 acquired immune response and hormonal changes including hypergastrinaemia. Antral-predominant inflammation leads to increased acid production from the uninflamed corpus and predisposes to duodenal ulceration; corpus-predominant gastritis leads to hypochlorhydria and predisposes to gastric ulceration and adenocarcinoma. Falling prevalence of H. pylori in developed countries has led to a falling incidence of associated diseases. However, whether there are disadvantages of an H. pylori-free stomach, for example increased risk of esosphageal adenocarcinoma, remains unclear.

The equilibria that allow bacterial persistence in human hosts

We propose that microbes that have developed persistent relationships with human hosts have evolved cross-signalling mechanisms that permit homeostasis that conforms to Nash equilibria and, more specifically, to evolutionarily stable strategies. This implies that a group of highly diverse organisms has evolved within the changing contexts of variation in effective human population size and lifespan, shaping the equilibria achieved, and creating relationships resembling climax communities. We propose that such ecosystems contain nested communities in which equilibrium at one level contributes to homeostasis at another. The model can aid prediction of equilibrium states in the context of further change: widespread immunodeficiency, changing population densities, or extinctions.

Current management of Helicobacter pylori infections in the elderly

Helicobacter pylori infection is a chronic gastric gram-negative infection that increases with age worldwide. However, the percentage age of H. pylori-positive elderly patients who are tested and treated for their infection remains very low. It is now demonstrated that H. pylori infection induces a whole cascade of events leading to gastric pathologies, such as peptic ulcer diseases, gastric precancerous lesions and gastric cancer. Recent data also demonstrated that H. pylori chronic infection can play a role in gastric aging, appetite regulation and extradigestive diseases, such as Alzheimer's disease, in the elderly. The diagnosis of H. pylori infection remains difficult to realize in the very old population, and the urea breath test obtains the best performance in this population. 1-week proton pump inhibitor-based triple therapy regimens are highly effective and well tolerated in elderly patients, and antibiotic resistance remains very low. Low compliance is the main factor related to treatment failure in this population.

Plasma acylated ghrelin levels are higher in patients with chronic atrophic gastritis

OBJECTIVES

Ghrelin is mainly produced by the endocrine cells of the gastric oxyntic mucosa. For this reason we decided to investigate the modification of the circulating levels not only of total but also of acylated ghrelin in a series of patients with chronic atrophic gastritis.

DESIGN

Twenty-five patients with chronic atrophic gastritis and 25 healthy subjects were studied. In all 50 subjects gastrin and total and acylated ghrelin levels were evaluated. All patients underwent endoscopy with multiple biopsies, and the possibility of Helicobacter pylori infection was investigated.

RESULTS

Significantly higher acylated ghrelin levels (82.8 +/- 61.3 vs. 35.1 +/- 17.1 pmol/l), acylated/total ghrelin ratio (0.422 +/- 0.202 vs. 0.152 +/- 0.085) and gastrin levels (1071 +/- 816 vs. 66 +/- 22 ng/l) were observed in the 25 patients with chronic atrophy than in the healthy subjects. Otherwise, no significant relationships were found when total ghrelin was correlated with the presence of atrophy, or with gastrin levels. In the healthy subjects, but not in the patients, acylated and total ghrelin levels were significantly higher in female than in male patients.

CONCLUSIONS

The increase in acylated ghrelin levels and in the acylated/total ghrelin ratio in patients with atrophy of the body and fundus can be explained by hypothesizing an increase in the acylating process in the presence of gastric atrophy. It suggests that there may be a compensatory increase in plasma active ghrelin concentration in response to gastric atrophy, a condition which causes a loss of ghrelin-producing cells and an increase in gastric pH.

Correlation between gastrointestinal symptoms and gastric leptin and ghrelin expression in patients with gastritis

The purpose of this study was to examine the changes in gastric ghrelin and leptin with respect to Helicobacter pylori infection and whether such changes affect the plasma levels of leptin and ghrelin. In addition, we examined the relationship between changes in gastric mucosal ghrelin and leptin levels and gastrointestinal symptoms. Sixty-three patients diagnosed with chronic gastritis were enrolled in the study. Twenty-nine patients were Helicobacter pylori negative and 34 were Helicobacter pylori positive. Expression of ghrelin and leptin mRNA in the gastric mucosa was measured using endoscopic biopsies from the fundus. Plasma levels of ghrelin and leptin were measured by radioimmunoassay. Expression of leptin mRNA in the gastric mucosa was significantly higher in Helicobacter pylori-positive patients than in negative patients (0.38 +/- 0.17 vs. 0.24 +/- 0.12, p = 0.039). The expression of ghrelin was lower in positive patients than in the negative group, although this difference was not significant (p = 0.07). However, there was no significant difference in plasma leptin and ghrelin levels. Gastric mucosal ghrelin mRNA expression was significantly lower in patients with dyspepsia than in those without (0.15 +/- 0.11 vs. 0.23 +/- 0.20, p = 0.05). Helicobacter pylori infection and gastrointestinal symptoms could be associated with leptin and ghrelin expression in the gastric mucosa.

Clinical significance of ghrelin concentration of plasma and tumor tissue in patients with gastric cancer

BACKGROUND

The nutritional status of gastric cancer patients is an important factor determining the outcome after a gastrectomy. Ghrelin is produced primarily in the gastrointestinal tract including the stomach, and has been reported to reflect the nutritional status and control homeostasis by influencing the level of food intake and adiposity. This study examined the difference in the plasma and tissue ghrelin levels according to the clinicopathological features and the extent of a gastric resection in gastric cancer patients who underwent a gastrectomy.

PATIENTS AND METHODS

Eighty patients over a 3 mo-period were divided into two groups according to the degree of preoperative weight loss (weight loss > or = 5% or < 5%) and the extent of the gastrectomy (subtotal or total gastrectomy). Blood samples were collected from all patients preoperatively and on postoperative day 7. The gastric tissues samples, including the tumor and normal tissues, were obtained from the resected stomach. The ghrelin levels in the plasma and tissue were measured using a commercial enzyme-linked immunosorbent assay kit.

RESULTS

There were no significant differences in the clinical characteristics and ghrelin levels in the plasma, gastric tumor tissue, and normal tissue according to the degree of weight loss. There was no correlation between the ghrelin levels in the plasma and tumor tissue. However, the ghrelin level in the tumor tissue was significantly lower than that in the normal tissue. There was an association between the degree of cellular differentiation and ghrelin production. A gastrectomy decreased the plasma ghrelin levels and nutritional index such as the body mass index, triceps skin fold, mid-arm muscle circumference, and biochemical markers regardless of the extent of the gastric resection.

CONCLUSIONS

Gastric cancer affects the production of ghrelin in the gastric mucosa. Moreover, ghrelin is produced mainly in the stomach even though it might be partially covered by the endogenous ghrelin produced by other organs after gastrectomy. However, more study will be needed to determine if there are other factors that have an impact on energy consumption, ghrelin secretion, and the changes in the ghrelin level after a gastrectomy.

Serum ghrelin levels and risk of subsequent adenocarcinoma of the esophagus

OBJECTIVE

Several large studies have shown a negative association between Helicobacter pylori (H. pylori) infection and esophageal adenocarcinoma. Diminution of gastric ghrelin secretion by H. pylori could protect against esophageal malignancy by decreasing appetite, food intake, and acid production, thereby decreasing weight and gastroesophageal reflux.

METHODS

We evaluated the association of ghrelin with esophageal adenocarcinoma using a population from a previous nested case-control study. Among 128,992 enrolled in a multiphasic health checkup (MHC) between 1964 and 1969, 52 patients developed esophageal adenocarcinoma by the year 2000. Three random controls from the MHC cohort were matched to each case by age, sex, race, and the date and site of their MHC. Serum samples collected at the MHC had been previously tested for IgG antibodies against H. pylori and the CagA protein. Serum ghrelin concentrations were determined by a commercial EIA on 52% of the initial subjects (31 cases and 79 controls).

RESULTS

A concentration of ghrelin greater than 3,200 pg/mL at MHC (fourth quartile) was associated with a lower risk of esophageal cancer (H. pylori and body mass index [BMI] adjusted OR=0.18 [CI 0.04-0.78]). This inverse association was seen only in overweight subjects (BMI>or=25, P value for interaction=0.09). The effects of H. pylori and ghrelin were independent.

CONCLUSION

Contrary to the original hypothesis, high rather than low serum ghrelin was associated with protection against esophageal adenocarcinoma but only among overweight subjects.

Influence of H pylori on plasma ghrelin in patients without atrophic gastritis

AIM: To determine the association between H pylori infection and serum ghrelin levels in patients without atrophic gastritis.

METHODS: Fifty consecutive patients (24 males and 26 females) with either H pylori-positive gastritis (n = 34) or H pylori-negative gastritis (n = 16) with normal gastric acid secretion determined by 24-h pHmetry and without atrophic gastritis in histopathology were enrolled in this study. Thirty-four H pylori-infected patients were treated with triple therapy consisting of a daily regimen of 30 mg lansoprazole bid, 1 g amoxicillin bid and 500 mg clarithromycin bid for 14 d, followed by an additional 4 wk of 30 mg lansoprazol treatment. H pylori infection was eradicated in 23 of 34 (67.6%) patients. H pylori-positive patients were given eradication therapy. Gastric acidity was determined via intragastric pH catethers. Serum ghrelin was measured by radioimmunoassay (RIA).

RESULTS: There was no signifficant difference in plasma ghrelin levels between H pylori-positive and H pylori-negative groups (81.10 ± 162.66 ng/L vs 76.51 ± 122.94 ng/L). In addition, there was no significant difference in plasma ghrelin levels and gastric acidity levels measured before and 3 mo after the eradication therapy.

CONCLUSION: H pylori infection does not influence ghrelin secretion in patients with chronic gastritis without atrophic gastritis.

Effects of Helicobacter pylori infection on gut appetite peptide (leptin, ghrelin) expression in elderly inpatients

The aim of the study was to investigate the relationship between gastritis and leptin and ghrelin in elderly patients. Patients older than 75 years undergoing an endoscopy were included. We reported data on nutritional status and Helicobacter pylori infection diagnosis (serology, 13C-urea breath test, culture, histology, and polymerase chain reaction on gastric biopsies). Gastric messenger RNA expression of leptin and ghrelin were quantified by real-time polymerase chain reaction. Sixty-two patients were included (84.7 +/- 5.2 years). H. pylori infection was associated with decreased gastric expression of leptin (p = .021), ghrelin (p =.002), and plasma ghrelin levels (p = .018). Atrophy was associated with decreased gastric leptin (p = .007) and ghrelin (p = .02). H. pylori infection correlated negatively with patient energy intake (r = -0.36; p = .001) and body mass index (r = -0.34; p = .018). The negative association between ghrelin and H. pylori infection may be related to a higher prevalence of atrophy and raises the possibility that H. pylori may be contributing to undernutrition in some older people.

Changes in plasma ghrelin levels, gastric ghrelin production, and body weight after Helicobacter pylori cure

BACKGROUND

Ghrelin is a body weight-regulating peptide produced and secreted primarily by the gastric mucosa. Helicobacter pylori infection impairs gastric ghrelin production, leading to a lower plasma ghrelin concentration. However, the effect of H. pylori eradication on plasma ghrelin levels and its relation to body weight change after H. pylori cure are still uncertain. We examined the association of plasma ghrelin levels with gastric ghrelin production and body weight change before and after H. pylori eradication.

METHODS

Plasma ghrelin concentrations, gastric ghrelin expression, and body weight were determined in a total of 134 consecutive individuals before and 12 weeks after successful H. pylori eradication. Gastric ghrelin expression was evaluated by determining mRNA expression levels and the number of ghrelin-producing cells in gastric mucosa biopsy specimens by real-time reverse transcriptase-polymerase chain reaction and immunohistochemistry, respectively.

RESULTS

Plasma ghrelin concentration increased in 50 patients and decreased in 84 patients after H. pylori eradication. After H. pylori cure, however, gastric preproghrelin mRNA expression was increased nearly fourfold (P < 0.0001), and the number of ghrelin-positive cells was increased or unchanged. In contrast, plasma ghrelin changes after H. pylori cure were inversely correlated with both body weight change (P < 0.0001) and initial plasma ghrelin levels (P < 0.0001).

CONCLUSIONS

Changes in plasma ghrelin concentrations before and after H. pylori cure were inversely correlated with body weight change and initial plasma ghrelin levels but not with gastric ghrelin production in Japanese patients.

LPS inhibits fasted plasma ghrelin levels in rats: role of IL-1 and PGs and functional implications

LPS injected intraperitoneally decreases fasted plasma levels of ghrelin at 3 h postinjection in rats. We characterized the inhibitory action of LPS on plasma ghrelin and whether exogenous ghrelin restores LPS-induced suppression of food intake and gastric emptying in fasted rats. Plasma ghrelin and insulin and blood glucose were measured after intraperitoneal injection of LPS, intravenous injection of IL-1beta and urocortin 1, and in response to LPS under conditions of blockade of IL-1 or CRF receptors by subcutaneous injection of IL-1 receptor antagonist (IL-1Ra) or astressin B, respectively, and prostaglandin (PG) synthesis by intraperitoneal indomethacin. Food intake and gastric emptying were measured after intravenous injection of ghrelin at 5 h postintraperitoneal LPS injection. LPS inhibited the elevated fasted plasma ghrelin levels by 47.6 +/- 4.9%, 58.9 +/- 3.3%, 74.4 +/- 2.7%, and 48.9 +/- 8.7% at 2, 3, 5, and 7 h postinjection, respectively, and values returned to preinjection levels at 24 h. Insulin levels were negatively correlated to those of ghrelin, whereas there was no significant correlation between glucose and ghrelin. IL-1Ra and indomethacin prevented the first 3-h decline in ghrelin levels induced by LPS, whereas astressin B did not. IL-1beta inhibited plasma ghrelin levels, whereas urocortin 1 had no influence. Ghrelin injected intravenously prevented an LPS-induced 87% reduction of gastric emptying and 61% reduction of food intake. These data showed that IL-1 and PG pathways are part of the early mechanisms by which LPS suppresses fasted plasma ghrelin and that exogenous ghrelin can normalize LPS-induced-altered digestive functions.

Metabolic profiling reveals a contribution of gut microbiota to fatty liver phenotype in insulin-resistant mice

Here, we study the intricate relationship between gut microbiota and host cometabolic phenotypes associated with dietary-induced impaired glucose homeostasis and nonalcoholic fatty liver disease (NAFLD) in a mouse strain (129S6) known to be susceptible to these disease traits, using plasma and urine metabotyping, achieved by (1)H NMR spectroscopy. Multivariate statistical modeling of the spectra shows that the genetic predisposition of the 129S6 mouse to impaired glucose homeostasis and NAFLD is associated with disruptions of choline metabolism, i.e., low circulating levels of plasma phosphatidylcholine and high urinary excretion of methylamines (dimethylamine, trimethylamine, and trimethylamine-N-oxide), coprocessed by symbiotic gut microbiota and mammalian enzyme systems. Conversion of choline into methylamines by microbiota in strain 129S6 on a high-fat diet reduces the bioavailability of choline and mimics the effect of choline-deficient diets, causing NAFLD. These data also indicate that gut microbiota may play an active role in the development of insulin resistance.

Bacteria and cancer: cause, coincidence or cure? A review

Research has found that certain bacteria are associated with human cancers. Their role, however, is still unclear. Convincing evidence links some species to carcinogenesis while others appear promising in the diagnosis, prevention or treatment of cancers. The complex relationship between bacteria and humans is demonstrated by Helicobacter pylori and Salmonella typhi infections. Research has shown that H. pylori can cause gastric cancer or MALT lymphoma in some individuals. In contrast, exposure to H. pylori appears to reduce the risk of esophageal cancer in others. Salmonella typhi infection has been associated with the development of gallbladder cancer; however S. typhi is a promising carrier of therapeutic agents for melanoma, colon and bladder cancers. Thus bacterial species and their roles in particular cancers appear to differ among different individuals. Many species, however, share an important characteristic: highly site-specific colonization. This critical factor may lead to the development of non-invasive diagnostic tests, innovative treatments and cancer vaccines.

Plasma leptin and ghrelin concentrations in patients with Crohn's disease

AIM

To determine the concentrations of leptin and ghrelin, which have opposite effects on appetite, energy expenditure, and weight control, in the plasma of patients with Crohn's disease (CD), which is often associated with weight loss and malnutrition.

METHODS

Plasma leptin and ghrelin 'concentrations were determined in 28 outpatients with CD by radioimmunoassay. Age- and sex-matched controls with and without Helicobacter pylori (H pylori) infection (28 for each) were enrolled in the study. Circulating levels of these hormones were assessed with respect to CD activity, disease localization and medical treatment.

RESULTS

There were no significant differences in ghrelin levels between CD patients and H pylori-negative controls. However, circulating ghrelin levels were significantly lower in H pylori-infected subjects than in CD patients and uninfected controls. Plasma leptin levels were comparable among the groups. Localization and medication profile had no significant impact on circulating ghrelin and leptin levels.

CONCLUSION

Apart from H pylori infection, CD itself has no significant influence on circulating ghrelin and leptin levels in the outpatients who were mostly in inactive state.

Gastric secretion

PURPOSE OF REVIEW

The purpose of this review is to summarize the pertinent literature published in the past year regarding the regulation of gastric exocrine and endocrine secretion.

RECENT FINDINGS

Gastric acid aids protein digestion; facilitates the absorption of iron, calcium, and vitamin B12; thwarts enteric infection; and prevents bacterial overgrowth. When levels of acid and proteolytic enzymes overwhelm the mucosal defense mechanisms, ulcers occur. To avoid damage under these harsh conditions, gastric acid must be finely regulated by overlapping neural (e.g. orexin, pituitary adenylate cyclase-activating polypeptide, nitric oxide, and galanin), hormonal (e.g. gastrin, cholecystokinin, and ghrelin), paracrine (e.g. histamine and somatostatin), and autocrine (e.g. transforming growth factor-alpha) pathways. The precise mechanisms whereby Helicobacter pylori induces perturbations in acid secretion are not known, but they seem to involve changes in somatostatin and perhaps ghrelin secretion. Acid secretion by parietal cells involves intracellular elevation of calcium and/or cyclic AMP, followed by a cascade that triggers translocation of the proton pump, HK-adenosine triphosphatase, from cytoplasmic tubulovesicles to the secretory canaliculi.

SUMMARY

An improved understanding of the pathways and mechanisms regulating gastric acid secretion may lead to the development of new strategies to prevent and treat acid peptic disorders as well as circumvent the adverse effects of currently prescribed antisecretory medications.

Helicobacter pylori infection is associated with reduced circulating ghrelin levels independent of body mass index

BACKGROUND

Ghrelin stimulates growth hormone and has orexigenic and adipogenic effects. Plasma ghrelin levels are reduced in obesity and possibly in Helicobacter pylori infection.

AIM

To investigate whether there was a relation between H. pylori infection, body mass index (BMI) and serum ghrelin or leptin levels.

METHODS

University students undergoing an annual health check-up were invited to participate. H. pylori status was based on the presence of specific IgG H. pylori antibodies in urine. Fasting serum ghrelin, leptin levels, and pepsinogen I and II levels were measured by enzyme immunoassay (EIA).

RESULTS

Eight hundred and one students volunteered. There was no significant difference in the height and BMI between those with and without H. pylori infection. The population of ghrelin study consisted of 132 (66 H. pylori-positive and 66 H. pylori-negative) students matched for age, sex, and BMI. The ghrelin level in the H. pylori-positive group was significantly lower (median 55 pmol/l) compared to the H. pylori-negative group (103 pmol/l) (p < .00001). Leptin, triglyceride, total cholesterol, and HDL-cholesterol were not different between the two groups, whereas LDL-cholesterol levels were significantly higher (106 versus 100 mg/dl) (p = .03) in the H. pylori-positive group. Leptin levels correlated with the BMI (r = 0.53) (p < .00001). Among H. pylori-positive subjects, ghrelin correlated only with pepsinogen I levels (r = 0.26, p = .04).

CONCLUSIONS

H. pylori infection was associated with a reduction in circulating ghrelin levels independent of sex and BMI.

Ghrelin in gastroenteric pathophysiology

Ghrelin, an acylated peptide produced predominantly by the stomach, has been discovered to be a natural ligand of the growth hormone secretagogue receptor 1a (GHS-R1a). It is localized in distinct cells of the gastric mucosa, mainly distributed in the mid portion of the oxyntic gland characterized by P/D1 granules in man and X/A-like granules in rodents. The ghrelin cell represents the second most frequent endocrine cell type after the enterochromaffin-like cells in gastric oxyntic mucosa, pointing to a potentially relevant role in the physiology of the stomach. Ghrelin has no relevant homology with any known gastrointestinal peptide and displays strong GH-releasing activity both in animals and in humans. However, in addition to stimulating GH secretion, ghrelin possesses several other endocrine and extraendocrine biological activities that are explained by the widespread distribution of ghrelin and GHS-R1a expression. In the rat, ghrelin exerts a control in gastric acid secretion and motility: the gastric acid secretion is stimulated by peripheral administration of high doses of ghrelin, but inhibited by very low doses of ghrelin delivered into the central nervous system. Moreover, ghrelin provides a potent and dose-related gastroprotective action against ethanol- and stress-induced gastric ulcers. The integrity of both nitric oxide (NO) system and capsaicin afferent nerves are required for the gastroprotective effect of ghrelin, whereas the vagus nerve might be involved in conveying ghrelinergic signal from periphery to the brain. In addition, prostaglandins derived by the constitutive cyclooxygenase (COX) activity are essential for the protective activity of ghrelin in ethanol and stress-induced gastric lesions. Given its prevailing role in physiological and pathophysiological gastric function, the discovery of ghrelin will open new perspectives and potential clinical implications in the gastroenteric field.

Helicobacter pylori and overweight status in the United States: data from the Third National Health and Nutrition Examination Survey

Obesity is an important public health problem in the United States. Because of its potential effects on gastric leptin homeostasis, Helicobacter pylori may play a role in regulating body weight. The authors' aim in this study was to examine the association between H. pylori colonization and overweight status. Nonpregnant participants in the Third National Health and Nutrition Examination Survey (1988-1994) aged > or = 20 years who had had H. pylori testing performed and body mass index (weight (kg)/height (m2)) measured were studied. Overweight was defined as a body mass index greater than or equal to 25. On the basis of serologic results, the participants were categorized into three H. pylori status groups: H. pylori-positive and cytotoxin-associated gene A (cagA)-positive (H. pylori+ cagA+), H. pylori-positive and cagA-negative (H. pylori+ cagA-), and H. pylori-negative (H. pylori-). Of the 7,003 subjects with complete body mass index and H. pylori data, 2,634 (weighted percentage, 22.9%) were H. pylori+ cagA+, 1,385 (15.1%) were H. pylori+ cagA-, and 2,984 (62.0%) were H. pylori-. The adjusted odds of being overweight were 1.17 (95% confidence interval: 0.98, 1.39; p = 0.075) for the H. pylori+ cagA+ group and 0.99 (95% confidence interval: 0.80, 1.22; p = 0.92) for the H. pylori+ cagA- group in comparison with H. pylori- subjects. Serum leptin levels did not differ significantly between the three H. pylori groups. In this US population-based study, there was no significant association between H. pylori colonization, cagA+ strains of H. pylori, and being overweight.

Ciprofloxacin suppresses bacterial overgrowth, increases fasting insulin but does not correct low acylated ghrelin concentration in non-alcoholic steatohepatitis

BACKGROUND

Insulin resistance and oxidative stress induced by products of small intestinal bacterial activity are putative factors in the pathogenesis of non-alcoholic steatohepatitis. Acylated ghrelin is the biologically active form of an orexigenic gastric hormone that modifies insulin sensitivity and body composition.

AIM

To investigate the effect of ciprofloxacin on small intestinal bacterial activity, ethanol, ghrelin and insulin in non-alcoholic steatohepatitis patients.

METHODS

Twelve non-alcoholic steatohepatitis patients and 11 controls were studied before and after ciprofloxacin 500 mg b.d. for 5 days. After an overnight fast, 75 g glucose was ingested and blood was sampled every 20 min for 120 min. Acylated and total ghrelin, ethanol and insulin were measured. Small intestinal bacterial activity was detected by glucose hydrogen breath test.

RESULTS

Mean (range) integrated plasma acylated ghrelin which was 102 (21-241) and 202 (88-366) pg/mL . 2 h in non-alcoholic steatohepatitis and controls respectively (P = 0.015). This difference persisted after correction for body mass index and was unaffected by ciprofloxacin treatment. One of six non-alcoholic steatohepatitis patients positive for small intestinal bacterial activity remained positive after ciprofloxacin. In contrast, the one healthy control positive for small intestinal bacterial activity remained positive after ciprofloxacin (P = 0.025). Ethanol was detected in two subjects in each group, becoming immeasurable after ciprofloxacin. In non-alcoholic steatohepatitis patients median (range) fasting insulin increased from 113 (10-223) to 152 (32-396) pmol/L (P < 0.02), after ciprofloxacin. This was accompanied by similar changes in insulin resistance.

CONCLUSIONS

Small intestinal bacterial activity is common in non-alcoholic steatohepatitis. Low acylated ghrelin in non-alcoholic steatohepatitis cannot be attributed to small intestinal bacterial activity. Changes in fasting insulin and ethanol following ciprofloxacin suggest that these parameters may be influenced by small intestinal bacterial activity.

Impact of Helicobacter pylori infection on gastric and plasma ghrelin dynamics in humans

OBJECTIVES

There are contradictory reports on the relationship between Helicobacter pylori and circulating ghrelin. We sought to clarify the influence of H. pylori infection on gastric and plasma ghrelin dynamics in humans.

METHODS

Using endoscopic biopsies from the corpus of 56 H. pylori-infected patients and 25 uninfected subjects, ghrelin mRNA expression levels and gastric ghrelin peptide contents were measured by real-time polymerase chain reaction and radioimmunoassay, respectively. We also measured plasma ghrelin concentrations and analyzed the numbers of ghrelin immunoreactive cells in the fundic gland area. Fifty-one patients with H. pylori infection were treated with a 7-day triple therapy consisting of lansoprazole, clarithromycin, and amoxicillin.

RESULTS

The gastric ghrelin mRNA expression level of H. pylori-positive patients (1.64 +/- 1.27 in arbitrary units) was significantly lower than in H. pylori-negative subjects (4.87 +/- 4.1, p < 0.0001). A similar trend was noted for ghrelin peptide contents (31.2 +/- 27.5 vs 81.2 +/- 64.1 ng/mg protein, respectively, p < 0.0001). There was no significant difference in the number of ghrelin immunoreactive cells/mm(2) in terms of H. plyori status. Plasma ghrelin concentrations in H. pylori-infected patients (144.6 +/- 7.8.8 fmol/ml) were significantly lower than in uninfected subjects (196.1 +/- 97.2, p < 0.05) and increased following cure of the infection. Plasma ghrelin levels correlated positively with the expression levels of ghrelin mRNA (r = 0.583, p < 0.0001) and peptide products (r = 0.574, p < 0.0001). There was a significant stepwise decrease in gastric ghrelin mRNA expression (p < 0.05), peptide contents (p < 0.01) and density of ghrelin immunoreactive cells (p < 0.05) with progression of histological severity of glandular atrophy in the corpus. The histological severity of chronic inflammation also negatively influenced the ghrelin mRNA expression (p < 0.001) and peptide production (p < 0.005).

CONCLUSIONS

H. pylori infection has a negative impact on gastric and plasma ghrelin dynamics. Chronic inflammatory and atrophic changes associated with the infection may affect gastric ghrelin biosynthesis and contribute to the low circulating levels.

Enhanced plasma ghrelin levels in Helicobacter pylori-colonized, interleukin-1-receptor type 1-homozygous knockout (IL-1R1-/-) mice

AIM: Ghrelin is an endogenous ligand for the growth hormone secretagogue receptor, and it plays a role in stimulating the growth hormone secretion, food intake, body weight gain and gastric motility. Eradication of

Helicobacter pylori (H pylori) was shown to be associated with increase of the body weight. On the other hand, H pylori infection evokes the release of gastric IL-1β. The present study was designed to investigate the involvement of the gastric IL-1 signal in the ghrelin dynamics in H pylori-colonized mice.

METHODS: Twelve-week-old female IL-1-receptor type 1-homozygous-knockout mice (IL-1R1^-/-) and their wild-type littermates (WT) were orally inoculated with H pylori (Hp group), while other cohorts received oral inoculation of culture medium (Cont group). Thirteen weeks after the inoculation, the mice were examined. The plasma and stomach ghrelin levels and the gastric preproghrelin mRNA were measured.

RESULTS: Although the WT mice with H pylori infection showed a significantly decreased body weight as compared with that of the animals without H pylori infection, H pylori infection did not influence the body weight of the IL-1R1-knockout (IL-1R1^-/-) mice. In the H pylori-infected IL-1R1^-/- mice, the total and active ghrelin levels in the plasma were significantly increased, and the gastric ghrelin level was decreased. No significant differences were noted in the gastric preproghrelin mRNA expression.

CONCLUSION: Ghrelin secretion triggered by H pylori infection might be suppressed by IL-1β, the release of which is also induced by the infection, resulting in the body weight loss of mice with H pylori infection.

Circulating ghrelin levels in patients with various upper gastrointestinal diseases

The stomach is the main source of circulating ghrelin. Plasma concentrations of this hormone in patients with various upper gastrointestinal diseases remain undetermined. Thus we measured plasma ghrelin levels by radioimmunoassay in 225 subjects, including 134 Helicobacter pylori-infected and 91 uninfected subjects. They included 67 patients with chronic gastritis (CG), 26 with benign gastric polyp (BGP), 24 with gastric ulcer (GU), 24 with reflux esophagitis (RE), 18 with duodenal ulcer (DU), 28 with acute gastritis (AG), 23 with gastric cancer (GC), and 39 who had normal mucosa on upper endoscopy (N). Plasma pepsinogen I and II levels were also measured. The extent of gastritis was assessed endoscopically. Ghrelin levels differed significantly among the different disease groups. Plasma ghrelin concentrations were lowest in the CG group, followed by the GU group, and highest in the AG patients. There was a significant difference in the levels between differentiated and undifferentiated GC. Ghrelin concentrations in BGP, RE, and DU patients were comparable to those in the N group. Ghrelin circulating levels were lower in H. pylori-positive than -negative individuals, but the significant differences among disease groups were still observed in H. pylori-infected and uninfected populations. Ghrelin concentrations correlated positively with plasma pepsinogen I levels and I/II ratios and inversely with the extent of H. pylori-related gastritis. Plasma ghrelin levels varied widely in diverse conditions of the upper digestive tract, reflecting the inflammatory and atrophic events of the background gastric mucosa. Further investigation is warranted to unravel the mechanisms of the high circulating ghrelin levels in certain upper gastrointestinal diseases.

Helicobacter pylori eradication has no effect on metabolic and inflammatory parameters

BACKGROUND

An increased risk in coronary heart disease associated with Helicobacter pylori (H. pylon) appears to be partially mediated by modifications of the atherogenic lipoprotein and inflammatory parameters. We conducted a controlled trial aimed at evaluating the changes of metabolic and inflammatory parameters after H. pylon eradication.

METHODS

We included in the study 169 patients with H. pylori infection and conducted a retrospective longitudinal survey of 87 subjects (76 men, 11 women) who received treatment for H. pylon eradication and 82 control subjects (63 men, 19 women) who did not receive treatment. We compared pre- and posteradication (one year after) the metabolic and inflammatory parameters, such as blood sugar, lipid profiles, insulin resistance, white blood cell count and C-reactive protein.

RESULTS

No significant changes from the baseline in metabolic and inflammatory parameters within each group were observed. Changes in the serum levels of metabolic and inflammatory parameters were similar between the two groups.

CONCLUSIONS

Metabolic and inflammatory parameters, including blood sugar, lipid profiles, insulin resistance, white blood cell count and C-reactive protein, were not changed after H. pylori eradication treatment. H. pylori eradication has no effect on metabolic and inflammatory parameters.

Impact of Helicobacter pylori infection on ghrelin and various neuroendocrine hormones in plasma

AIM: Ghrelin, an endogenous ligand for growth hormone secretagogue receptor, influences appetite, energy balance, gastric motility and acid secretion. The stomach is the main source of circulating ghrelin. There are inconsistent reports on the influence of Helicobacter pylori (H pylori) infection on circulating ghrelin levels. We sought to elucidate the relationship between ghrelin and various peptides in plasma, with special reference to H pylori.

METHODS: Plasma ghrelin levels were measured by radioimmunoassay in 89 subjects who were referred for upper gastrointestinal endoscopy, consisting of 42 H pylori infected and 47 uninfected ones. Plasma gastrin, somatostatin, leptin, insulin-like growth hormone 1 (IGF-1) and chromogranin A concentrations were also measured. Twelve patients were treated with anti- H pylori regimen.

RESULTS: Ghrelin circulating levels were greatly decreased in H pylori-positive than negative individuals (194.2±90.2 fmol/mL and 250.4±84.1 respectively, P<0.05), but did not significantly alter following the cure of infection (176.5±79.5 vs 191.3±120.4). There was a significant negative correlation between circulating ghrelin and leptin levels, as well as body mass index, for the whole and uninfected population, but not in H pylori-infected patients. Plasma ghrelin concentrations correlated positively with IGF-1 in H pylori-negative group and negatively with chromogranin A in the infected group. There were no significant correlations among circulating levels of ghrelin, gastrin and somatostatin irrespective of H pylori status.

CONCLUSION: H pylori infection influences plasma ghrelin dynamics and its interaction with diverse bioactive peptides involved in energy balance, growth and neuroendocrine function.

Is Helicobacter pylori seropositivity related to body mass index in the United States?

BACKGROUND

Helicobacter pylori infection may decrease serum ghrelin and increase gastric leptin levels, which may, in turn, decrease body mass index.

AIM

To determine whether H. pylori seropositivity is associated with body mass index.

METHODS

Serum H. pylori and cytotoxin-associated gene product A (CagA) antibody levels were measured on 6724 adult participants of the third National Health and Nutrition Examination Survey (1988-91). We evaluated the association between H. pylori/CagA antibody status [both negative (-/-), H. pylori-positive/CagA-negative (+/-), or both positive (+/+)] and body mass index, adjusting for sociodemographic factors. We also investigated whether H. pylori/cytotoxin-associated gene product A antibody status was associated with fasting serum leptin levels.

RESULTS

H. pylori/CagA antibody status was not associated with obesity (body mass index > or = 30 kg/m(2)) [adjusted odds ratio (OR) 1.2, 95% CI: 0.9-1.6 comparing (+/+) to (-/-) and adjusted OR 1.1, 95% CI: 0.8-1.5 comparing (+/-) to (-/-)], overweight (body mass index 25 to <30 kg/m(2)) [adjusted OR 1.0, 95% CI: 0.7-1.2 comparing (+/+) to (-/-) and adjusted OR 1.0, 95% CI: 0.8-1.3 comparing (+/-) to (-/-)], or fasting serum leptin level in the USA population.

CONCLUSIONS

H. pylori seropositivity and CagA antibody status are not associated with body mass index or fasting serum leptin level.

Enhanced production of leptin in gastric fundic mucosa with Helicobacter pylori infection

AIM: To determine the concentrations of leptin in plasma and gastric fundic mucosa in humans, with reference to Helicobacter pylori (H pylori) infection, and their association with gastric mucosal levels of interleukin (IL)-1β, IL-6 and IL-8.

METHODS: Plasma leptin concentrations were determined in 135 outpatients with non-ulcer dyspepsia, consisting of 95 H pylori-infected and 40 uninfected subjects, and 13 patients before and after cure of the infection with anti-H pylori regimen. Using biopsy samples that were endoscopically obtained from the middle corpus along the greater curvature, gastric leptin contents were measured by radioimmunoassay and the mucosal concentrations of IL-1β, IL-6 and IL-8 were measured by enzyme linked immunosorbent assay. We also analysed the expression of leptin in the fundic mucosa by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry.

RESULTS: The mucosal levels of leptin in the fundic mucosa of H pylori-infected patients were significantly higher than those of uninfected patients. The amount of gastric leptin correlated positively with the mucosal levels of IL-1β and IL-6, but not IL-8. Circulating leptin correlated with body mass index, but not with H pylori status, and there was no change in plasma leptin levels following cure of the infection. Leptin immunoreactive cells were noted in the lower half of the fundic glands, and its expression of messenger ribonucleic acid in the oxyntic mucosa was detected by RT-PCR.

CONCLUSION: Leptin production is enhanced in H pylori-infected gastric mucosa. Gastric leptin may be involved in immune and inflammatory response during H pylori infection, through interaction with proinflammatory cytokines.

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Effect of Helicobacter pylori infection on ghrelin expression in human gastric mucosa

OBJECTIVES

One of the counter-effects of Helicobacter pylori eradication therapy is subsequent obesity. Ghrelin is a recently discovered growth hormone releasing peptide. This endogenous secretagogue increases appetite and facilitates fat storage. The majority of circulating ghrelin is produced in the gastric mucosa. Therefore, we aimed at investigating changes in ghrelin immunoreactivity in gastric mucosa tissues of patients infected with H. pylori.

METHODS

Sixty-one patients with H. pylori infection (25 cases each of duodenal and gastric ulcer, and 11 cases of gastritis) and 22 healthy controls without H. pylori infection were included in the study. H. pylori-infected patients received standard proton pump-based triple therapy followed by histological examination and (13)C-urea breath test to confirm H. pylori eradication. H. pylori was eradicated in 50 out of 61 patients. Biopsy specimens were obtained from antrum and corpus before and 3 months following eradication. Ghrelin expression was evaluated immunohistochemically with an anti-ghrelin antibody, and the number of ghrelin-positive cells determined per 1 mm(2) of the lamina propria mucosa.

RESULTS

There was no relationship between ghrelin immunoreactivity and body weight or body mass index for healthy controls. The number of ghrelin-positive cells was significantly lower for H. pylori-infected patients than for healthy controls. However, the ghrelin-positive cell number increased significantly following H. pylori eradication without significant change in severity of atrophy.

CONCLUSIONS

These data indicated that H. pylori infection affected ghrelin expression. After H. pylori eradication, gastric tissue ghrelin concentration increased significantly. This could lead to the increased appetite and weight gain seen following H. pylori eradication.

Gastric secretion

PURPOSE OF REVIEW

The purpose of this chapter is to summarize and place into perspective the past year's literature regarding the regulation of gastric exocrine and endocrine secretion.

RECENT FINDINGS

To prevent acid and pepsin from overwhelming mucosal defense mechanisms and causing injury, the secretion of gastric acid is precisely regulated by a variety of central (eg, neuropeptide Y, corticotropin-releasing factor, and neuromedin U) and peripheral (eg, gastrin, histamine, acetylcholine, somatostatin, cholecystokinin, calcitonin gene-related peptide, leptin, and parietal cell) pathways. These pathways regulate the acid-producing parietal cell directly and/or indirectly by regulating the secretion of histamine from enterochromaffin-like cells, gastrin from G cells, and somatostatin from D cells. Recently, genetically engineered mouse models have been used to reevaluate the neural, hormonal, and paracrine pathways that physiologically regulate acid secretion.

SUMMARY

An improved understanding of the pathways and mechanisms regulating gastric acid secretion should lead to the development of novel therapies to prevent and treat acid-peptic disorders as well as circumvent the adverse effects of currently used antisecretory medications such as the acid rebound observed after discontinuation of proton pump inhibitors.

Drosophila lifespan enhancement by exogenous bacteria

We researched the lifespan of Drosophila under axenic conditions compared with customary procedure. The experiments revealed that the presence of bacteria during the first week of adult life can enhance lifespan, despite unchanged food intake. Later in life, the presence of bacteria can reduce lifespan. Certain long-lived mutants react in different ways, indicating an interplay between bacteria and longevity-enhancing genes.