Effect of Helicobacter pylori on gastrointestinal microbiota: a population-based study in Linqu, a high-risk area of gastric cancer.

OBJECTIVE: Gastrointestinal microbiota may be involved in Helicobacter pylori-associated gastric cancer development. The aim of this study was to explore the possible microbial mechanisms in gastric carcinogenesis and potential dysbiosis arising from H. pylori infection. DESIGN: Deep sequencing of the microbial 16S ribosomal RNA gene was used to investigate alterations in paired gastric biopsies and stool samples in 58 subjects with successful and 57 subjects with failed anti-H. pylori treatment, relative to 49 H. pylori negative subjects. RESULTS: In H. pylori positive subjects, richness and Shannon indexes increased significantly (both p<0.001) after successful eradication and showed no difference to those of negative subjects (p=0.493 for richness and p=0.420 for Shannon index). Differential taxa analysis identified 18 significantly altered gastric genera after eradication. The combination of these genera into a Microbial Dysbiosis Index revealed that the dysbiotic microbiota in H. pylori positive mucosa was associated with advanced gastric lesions (chronic atrophic gastritis and intestinal metaplasia/dysplasia) and could be reversed by eradication. Strong coexcluding interactions between Helicobacter and Fusobacterium, Neisseria, Prevotella, Veillonella, Rothia were found only in advanced gastric lesion patients, and were absent in normal/superficial gastritis group. Changes in faecal microbiota included increased Bifidobacterium after successful H. pylori eradication and more upregulated drug-resistant functional orthologs after failed treatment. CONCLUSION: H. pylori infection contributes significantly to gastric microbial dysbiosis that may be involved in carcinogenesis. Successful H. pylori eradication potentially restores gastric microbiota to a similar status as found in uninfected individuals, and shows beneficial effects on gut microbiota.

A large randomised controlled intervention trial to prevent gastric cancer by eradication of Helicobacter pylori in Linqu County, China: baseline results and factors affecting the eradication.

OBJECTIVE: To clarify the full range of benefits and adverse consequences of Helicobacter pylori eradication as a strategy for gastric cancer prevention, the community-based intervention trial was launched in Linqu County, China. DESIGN: A total of 184,786 residents aged 25-54 years were enrolled in this trial and received (13)C-urea breath test. H. pylori positive participants were assigned into two groups, either receiving a 10-day quadruple anti-H. pylori treatment or lookalike placebos together with a single dosage of omeprazole and bismuth. RESULTS: The prevalence of H. pylori in trial participants was 57.6%. A total of 94,101 subjects completed the treatment. The overall H. pylori eradication rate was 72.9% in the active group. Gender, body mass index, history of stomach disease, baseline delta over baseline-value of (13)C-urea breath test, missed medication doses, smoking and drinking were independent predictors of eradication failure. The missed doses and high baseline delta over baseline-value were important contributors in men and women (all Ptrend<0.001). However, a dose-response relationship between failure rate and smoking or drinking index was found in men (all Ptrend<0.001), while high body mass index (Ptrend<0.001) and history of stomach disease were significant predictors in women. The treatment failure rate increased up to 48.8% (OR 2.87, 95% CI 2.24 to 3.68) in men and 39.4% (OR 2.67, 95% CI 1.61 to 4.42) in women with multiple factors combined. CONCLUSIONS: This large community-based intervention trial to eradicate H. pylori is feasible and acceptable. The findings of this trial lead to a distinct evaluation of factors influencing eradication that should be generally considered for future eradication therapies. TRIAL REGISTRATION NUMBER: ChiCTR-TRC-10000979 in accordance with WHO ICTRP requirements.

Helicobacter pylori antibody responses and evolution of precancerous gastric lesions in a Chinese population.

Helicobacter pylori-specific proteins are involved in gastric carcinogenesis. To investigate the seroprevalence of six H. pylori-specific antibodies in patients with different gastric histology, and the impact of seropositivities on the evolution of precancerous gastric lesions, a follow-up study was conducted in Linqu County, China. The seropositivities for CagA, VacA, GroEL, UreA, HcpC and gGT were assessed by recomLine analysis in 573 H. pylori-positive subjects and correlated with evolution of precancerous gastric lesions. We found that the score of H. pylori recomLine test was significantly increased in subjects with chronic atrophic gastritis (CAG, p < 0.0001) or intestinal metaplasia (IM, p = 0.0125), and CagA was an independent predictor of advanced gastric lesions, adjusted odds ratios (ORs) were 2.54 (95% CI = 1.42-4.55) for IM and 2.38 (95% CI = 1.05-5.37) for dysplasia (DYS). Moreover, seropositivities for CagA and GroEL were identified as independent predictors for progression of gastric lesions in a longitudinal study, and ORs were 2.89 (95% CI = 1.27-6.59) and 2.20 (95% CI = 1.33-3.64), respectively. Furthermore, the risk of progression was more pronounced in subjects with more than three positive antigens (p(for) trend = 0.0003). This population-based study revealed that seropositivities for CagA and GroEL might be potential markers to identify patients infected with high-risk H. pylori strains, which are related to the development of GC in a Chinese high-risk population, and recomLine test might serve as a tool for risk stratification.

Microbiota alteration at different stages in gastric lesion progression: a population-based study in Linqu, China.

In addition to Helicobacter pylori (H.pylori), gastric microbiota may be involved in carcinogenesis process. However, the longitudinal study to assess changes in the gastric microbiota associated with the development of gastric carcinogenesis is still limited. The aim of this study is to explore dynamic microbial alterations in gastric cancer (GC) development based on a 4-year endoscopic follow-up cohort in Linqu County, China. Microbial alterations were investigated by deep sequencing of the microbial 16S ribosomal RNA gene in 179 subjects with various gastric lesions, and validated in paired gastric biopsies prospectively collected before and after lesion progression and in non-progression controls. Significant differences were found in microbial diversity and community structure across various gastric lesions, with 62 candidate differential taxa between at least two lesion groups. Further validations identified Helicobacter, Bacillus, Capnocytophaga and Prevotella to be associated with lesion progression-to-dysplasia (DYS)/GC (all P < 0.05), especially for subjects progressing from intestinal metaplasia (IM) to DYS/GC. The combination of the four genera in a microbial dysbiosis index showed a significant difference after lesion progression-to-DYS/GC compared to controls (P = 0.027). The panel including the four genera identified subjects after progression-to-DYS/GC with an area under the receiver-operating curve (AUC) of 0.941. Predictive significance was found before lesion progression-to-DYS/GC with an AUC = 0.776 and an even better AUC (0.927) for subjects progressing from IM to DYS/GC. Microbiota may play different roles at different stages in gastric carcinogenesis. A panel of bacterial genera associated with gastric lesions may help to assess gastric microbial dysbiosis and show potential predictive values for lesion progression. Our findings provide new clues for the microbial mechanism of H.pylori-associated carcinogenesis.

Association Between Gut Microbiota and Helicobacter pylori-Related Gastric Lesions in a High-Risk Population of Gastric Cancer.

Eradication of Helicobacter pylori has been found to be effective for gastric cancer prevention, but uncertainties remain about the possible adverse consequences such as the potential microbial dysbiosis. In our study, we investigated the association between gut microbiota and H. pylori-related gastric lesions in 47 subjects by deep sequencing of microbial 16S ribosomal RNA (rRNA) gene in fecal samples. The dominant phyla in fecal samples were Bacteroidetes, Firmicutes, and Proteobacteria with average relative abundances of 54.77, 31.37 and 12.91%, respectively. Microbial diversity analysis showed that observed species and Shannon index were increased in subjects with past or current H. pylori infection compared with negative subjects. As for the differential bacteria, the average relative abundance of Bacteroidetes was found to significantly decrease from H. pylori negative (66.16%) to past infection group (33.01%, p = 0.007), as well as from normal (76.49%) to gastritis (56.04%) and metaplasia subjects (46.83%, p = 0.027). For Firmicutes and Proteobacteria, the average relative abundances showed elevated trends in the past H. pylori infection group (47.11, 20.53%) compared to negative group (23.44, 9.05%, p = 0.068 and 0.246, respectively), and similar increased trends were also found from normal (18.23, 5.05%) to gastritis (35.31, 7.23%, p = 0.016 and 0.294, respectively) or metaplasia subjects (32.33, 20.07%, both p < 0.05). These findings suggest that the alterations of fecal microbiota, especially the dominant phyla of Bacteroidetes, Firmicutes and Proteobacteria, may be involved in the process of H. pylori-related gastric lesion progression and provide hints for future evaluation of microbial changes after H. pylori eradication.

Long-term outcome and prognostic factors of patients with hilar cholangiocarcinoma.

AIM: To evaluate the long-term outcome and prognostic factors of patients with hilar cholangiocarinoma. METHODS: Ninety-six consecutive patients underwent treatment for malignant hilar bile duct tumors during 1995-2005. Of the 96 patients, 20 were initially treated with surgery (n = 2 R0 / n = 18 R1). In non-operated patients, data analysis was performed retrospectively. RESULTS: Among the 96 patients, 76 were treated with endoscopic transpapillary (ERC, n = 45) and/or percutaneous transhepatic biliary drainage (PTBD, n = 31). The mean survival time of these 76 patients undergoing palliative endoscopic and/or percutaneous drainage was 359 +/- 296 d. The mean survival time of patients with initial bilirubin levels > 10 mg/dL was significantly lower (P < 0.001) than patients with bilirubin levels < 10 mg/dL. The mean survival time of patients with Bismuth stage II (n = 8), III (n = 28) and IV (n = 40) was 496 +/- 300 d, 441 +/- 385 d and 274 +/- 218 d, respectively. Thus, patients with advanced Bismuth stage showed a reduced mean survival time, but the difference was not significant. The type of biliary drainage had no significant beneficial effect on the mean survival time (ERC vs PTBD, P = 0.806). CONCLUSION: Initial bilirubin level is a significant prognostic factor for survival of patients. In contrast, age, tumor stage according to the Bismuth-Corlette classification, and types of intervention are not significant prognostic parameters for survival. Palliative treatment with endoscopic or percutaneous biliary drainage is still suboptimal, new diagnostic and therapeutic tools need to be evaluated.

Cut-off optimization for 13C-urea breath test in a community-based trial by mathematic, histology and serology approach.

The performance of diagnostic tests in intervention trials of Helicobacter pylori (H.pylori) eradication is crucial, since even minor inaccuracies can have major impact. To determine the cut-off point for 13C-urea breath test (13C-UBT) and to assess if it can be further optimized by serologic testing, mathematic modeling, histopathology and serologic validation were applied. A finite mixture model (FMM) was developed in 21,857 subjects, and an independent validation by modified Giemsa staining was conducted in 300 selected subjects. H.pylori status was determined using recomLine H.pylori assay in 2,113 subjects with a borderline 13C-UBT results. The delta over baseline-value (DOB) of 3.8 was an optimal cut-off point by a FMM in modelling dataset, which was further validated as the most appropriate cut-off point by Giemsa staining (sensitivity = 94.53%, specificity = 92.93%). In the borderline population, 1,468 subjects were determined as H.pylori positive by recomLine (69.5%). A significant correlation between the number of positive H.pylori serum responses and DOB value was found (rs = 0.217, P < 0.001). A mathematical approach such as FMM might be an alternative measure in optimizing the cut-off point for 13C-UBT in community-based studies, and a second method to determine H.pylori status for subjects with borderline value of 13C-UBT was necessary and recommended.

Eradication of H pylori infection in a rural population: one-day quadruple therapy versus 7-day triple therapy.

AIM: To compare the one-day quadruple therapy with a standard 7-d triple therapy for H pylori eradication in a rural population of China. METHODS: A total of 396 patients with (13)C-urea breath test positive for H pylori were assigned into two groups: 239 patients received one-day quadruple therapy (amoxicillin 2000 mg qid; metronidazole 500 mg qid; bismuth citrate 900 mg qid and lansoprazole 60 mg once daily) and 157 patients received 7-d standard triple therapy (amoxicillin 1000 mg bid; clarithromycin 500 mg bid and lansoprazole 30 mg bid). All the patients underwent a (13)C-UBT to assess the eradication of H pylori infection six weeks after treatment. RESULTS: Two hundred and twenty-nine patients completed the one-day therapy (95.8%) and 148 patients completed the 7-d therapy (94.2%). The one-day therapy eradicated H pylori infection in 64 patients (27.95%). In contrast, 103 patients (69.59%) were H pylori negative after the 7-d therapy (P < 0.01). CONCLUSION: This pilot study suggests there is no beneficial effect of the one-day therapy in treatment of H pylori infection compared with the 7-d standard therapy.

Carbohydrate malabsorption in clinical routine: a prospective observational study.

BACKGROUND/AIMS: Nonspecific abdominal symptoms are a serious problem throughout the world. Among the multitude of differential diagnoses in carbohydrate malabsorption, only incomplete absorption of lactose is mentioned, while malabsorption of fructose and sorbitol--which occurs much more often, at least in the Western world--is usually not included. METHODOLOGY: During a 6-month period, all patients (n=90; 33 males, median age 45 years, range 10-81; 57 females, median age 47 years, range 15-71) who consecutively presented for H2 exhalation tests were evaluated. In addition to the test results, data were obtained from the referring physicians and from the family doctors responsible for the patients' long-term treatment regarding the role of the test results in the treatment of the patients. Finally, the patients were also asked whether any improvement in their symptoms had followed from the test results. RESULTS: Lactulose tests were normal in only 63% of the patients. As with the other sugars, at least one form of malabsorption was detected in 47 patients (52%). The malabsorption rate was 34% after lactose, 61% after fructose, and 91% after the intake of sorbitol. The referring physicians evaluated the test results as having been important in 52% of the patients, while the family doctors considered that there was some benefit for the patients in 77% of the cases. The patients themselves reported an improvement in 75% of cases. CONCLUSIONS: These data again show that carbohydrate malabsorption is an important differential diagnosis in patients with nonspecific abdominal complaints. However, the data also make it clear that caution is advisable both in establishing the indication for the tests and in interpreting the results. Despite this, carbohydrate malabsorption appears to be an underestimated problem in a considerable number of patients.

Generation of neutralizing mouse anti-mouse IL-18 antibodies for inhibition of inflammatory responses in vivo.

The proinflammatory cytokine IL-18 mediates IFN-gamma production as well as the induction of Th1 polarized immune responses in synergy with IL-12. In this study, we describe the production of isogeneic monoclonal antibodies (Mabs) directed against murine IL-18 (mIL-18). Immunization of IL-18-deficient mice with recombinant mIL-18 in the presence of CpG-oligodeoxynucleotides (CpG-ODN) and alum as adjuvant resulted in high anti-IL-18 serum titers. We could identify two Mabs, SK721-2 and SK113AE-4, which were able to bind to IL-18 and neutralize its IFN-gamma inducing effect in vitro with an IC(50) of 40-100 ng/ml. In vivo, LPS-induced IFN-gamma production was reduced by 60-85% following a single administration of Mabs SK113AE-4 or SK721-2. Since IL-18 is likely to be involved in the pathogenesis of inflammatory diseases such as rheumatoid arthritis or Crohn's disease, neutralizing mouse anti-mouse IL-18 Mabs have the potential to become valuable tools for the therapeutic exploration of long-term IL-18 blockade in vivo.

Effectiveness of theophylline prophylaxis of renal impairment after coronary angiography in patients with chronic renal insufficiency.

Contrast media can lead to renal impairment that results in longer hospitalization and increased mortality. Adenosine is a crucial mediator of contrast-induced nephropathy (CIN; an increase in serum creatinine of >or=0.5 mg/dl within 48 hours). Therefore, it was the purpose of our study to investigate whether the adenosine antagonist theophylline reduces the incidence of CIN after coronary angiography. We also characterized risk factors for CIN after coronary angiography. One hundred patients with serum creatinine concentrations of >or=1.3 mg/dl randomly received 200 mg IV theophylline or placebo 30 minutes before coronary angiography (amount of contrast medium >or=100 ml). Patients who received theophylline and the controls were comparable with regard to baseline creatinine levels (means +/- SD) (1.65 +/- 0.41 vs 1.72 +/- 0.69 mg/dl) and the amount of contrast medium received (235 +/- 89 vs 261 +/- 139 ml). Theophylline significantly reduced the incidence of CIN (4% vs 20%, p = 0.0138). With placebo, creatinine significantly increased at 12 (1.82 +/- 0.79 mg/dl, p = 0.0057), 24 (1.90 +/- 0.86 mg/dl, p = 0.0001), and 48 hours (1.90 +/- 0.89 mg/dl, p = 0.0007) after administration of contrast medium. With pretreatment with theophylline, mean creatinine only increased 24 hours after contrast medium administration (1.70 +/- 0.40 mg/dl, p = 0.029), but was stable 12 hours (1.65 +/- 0.43 mg/dl, p = 0.99) and 48 hours after contrast medium administration (1.65 +/- 0.41 mg/dl, p = 0.99). The following parameters were significantly associated with contrast-induced renal impairment: Cigarroa quotient >5 (contrast medium [milliters] x serum creatinine/body weight [kg]), elevated troponin T, >300 ml of contrast medium, and emergency angiography. In conclusion, theophylline reduces the incidence of CIN in patients with chronic renal insufficiency undergoing coronary angiography. It should be used especially in patients receiving large amounts of contrast medium, and in patients with a Cigarroa quotient of >5 and/or elevated troponin T levels.

Haemodialysis for the prevention of contrast-induced nephropathy: outcome of 31 patients with severely impaired renal function, comparison with patients at similar risk and review.

RATIONALE AND OBJECTIVES: To investigate whether haemodialysis prevents contrast-induced nephropathy (definition: increase of serum-creatinine of >or= 0.5 mg/dL within 7 days). MATERIALS AND METHODS: Thirty-one patients (mean serum-creatinine 4.01 +/- 1.83 mg/dL) were dialyzed for 4.36 +/- 1.0 hours within one hour after 278.4 +/- 160.5 mL of contrast medium. RESULTS: Dialysis resulted in a significant reduction of serum-creatinine (2.25 +/- 1.46 mg/dL; P< 0.0001) and stable mean serum-creatinine levels 2, 3, 4, and 7 days after contrast medium and at discharge compared with baseline values. However, 19 patients (61%) developed contrast-induced nephropathy within 7 days. Four patients had to be repeatedly dialyzed. A comparison of our patients' 48 hours-incidence of contrast-induced nephropathy (9/31; 29%) versus patients at comparable risk included in seven previous studies demonstrated a prophylactic effect of dialysis only versus a subgroup in one study. CONCLUSIONS: Data provide no hint that haemodialysis prevents contrast-induced nephropathy. Therefore, postprocedural dialysis should be restricted to patients participating in clinical studies.

Superior mesenteric artery syndrome: diagnosis and treatment from the gastroenterologist's view.

BACKGROUND: Superior mesenteric artery syndrome (SMAS) is caused by compression of the third part of the duodenum between the superior mesenteric artery and the aorta. It occurs most frequently in patients with rapid weight loss. METHODS: We report two young patients, who each presented with a longstanding history of postprandial abdominal pain, nausea, and voluminous vomiting. The diagnosis of SMAS was established by digital fluoroscopy and contrast-enhanced spiral computed tomography (CT) scan. The findings obtained by endoscopic ultrasound (EUS) at the site of duodenal compression, using a miniprobe, were of substantial diagnostic value and in good agreement with the radiological observations. RESULTS: Both patients, once diagnosed, were treated conservatively by providing enteral or parenteral high caloric nutrition. Weight gain was accompanied by the complete relief of symptoms. CONCLUSIONS: Pathogenesis, diagnostic procedures, and therapy are reviewed in order to draw attention to this rare entity.

Genetic variants of toll-like receptor 2 and 5, helicobacter pylori infection, and risk of gastric cancer and its precursors in a chinese population.

BACKGROUND: Genetic polymorphisms of Toll-like receptors (TLR) may influence the outcome of Helicobacter pylori infection and play important roles in gastric carcinogenesis. To screen the genetic variants of TLR2 and TLR5, and evaluate their associations with gastric cancer (GC) and its precursors, a population-based study was conducted in Linqu County, Shandong Province, China. METHODS: Genetic variants were identified by PCR-based denaturing high-performance liquid chromatography and PCR-restriction fragment length polymorphism analysis in 248 GC cases, 846 subjects with advanced gastric lesions including 350 dysplasia and 496 intestinal metaplasia, and 496 superficial gastritis/mild chronic atrophic gastritis controls. RESULTS: Nine allelic variants each were detected within the promoter and exons of TLR2 and TLR5. Among those, TLR2 c. -196 to -174 del carriers (ins/del+del/del) showed a significantly decreased risk of GC (adjusted OR, 0.66; 95% CI: 0.48-0.90), whereas TLR5 rs5744174 C carriers (TC+CC) had an increased risk of GC (OR, 1.43; 95% CI: 1.03-1.97). Further analysis indicated an elevated risk of GC in subjects with the TLR5 rs5744174 TC+CC genotype and H. pylori infection (OR, 3.35; 95% CI: 2.13-5.26), and a significant interaction between rs5744174 and H. pylori infection was observed (OR, 2.15; 95% CI: 1.12-4.16). CONCLUSION: These findings suggest that TLR2 c. -196 to -174 ins > del, TLR5 rs5744174 and interaction between rs5744174 and H. pylori infection were associated with the development of GC. IMPACT: TLR2 and TLR5 polymorphisms may play important roles in the process of H. pylori-related gastric carcinogenesis.

A placebo-controlled trial of 10-day bismuth-based quadruple therapy to eradicate Helicobacter pylori infection; a pilot study for the large Linqu County trial.

AIM: To explore a low-cost and highly-effective therapy for eradication of Helicobacter pylori (H. pylori), a placebo-controlled trial of quadruple therapy was conducted in a population at high risk of gastric cancer in Linqu County of Shandong Province, China. METHODS: Two hundred and seventy-seven adults aged 35-54 years with H. pylori infection in three villages were assigned to two groups: treatment (n=189 in two villages) and placebo (n=88 in one village). Participants received either a 10-day oral quadruple therapy regimen with omeprazole (20 mg, twice daily); tetracycline (750 mg, three times daily); metronidazole (500 mg, three times daily) and bismuth potassium citrate (300 mg, twice daily), or a similar lookalike placebo regimen. The status of H. pylori infection in each trial participant before and after six weeks of treatment was determined by a 13C-urea breath test. RESULTS: One hundred and seventy-four of 189 participants completed the quadruple therapy (92.1%) and 84 participants completed the placebo therapy (95.5%). The H. pylori eradication rate by intention-to-treat analysis was 76.7% (145 of 189) in the treatment group and 1.1% (1 of 88) in the placebo group, respectively; by per-protocol analysis it was 83.3% (145 of 174) in the treatment group and 1.2% (1 of 84) in the placebo group, respectively. CONCLUSION: In a high-risk area of gastric cancer, we conducted a high compliance, tolerable, low side-effect and lowcost therapy of anti-H. pylori. The eradication rate of the 10-day quadruple treatment was more than 80% and significantly higher than the triple therapy regimen used in this population in an earlier trial.