Helicobacter pylori (H. pylori) causes chronic gastritis in human stomach, a minority of which progress to peptic ulcer disease, atrophic gastritis, or gastric malignancies. Clinical outcomes of H. pylori infection has been shown to depend on the variability of H. pylori virulence factors, host susceptibility, environmental factors and their interactions. This review provides an update on the molecular pathogenesis of H. pylori infection, focused on H. pylori virulence factors, H. pylori-gastric epithelium interactions, and modulation of host cell signaling. Understanding of H. pylori molecular pathogenic mechanism will facilitate the development of novel treatment strategies for eradication of the bacterium and prevention of H. pylori-induced gastropathy.
Helicobacter Infections/microbiology ; Helicobacter pylori/*pathogenicity ; Humans ; *Virulence Factors

Helicobacter pylori (H. pylori), a long term colonizer of human stomach is known to infect a half of mankind. Gastric and duodenal ulcer, gastric adenocarcinoma and MALT lymphoma develop in a subset of infected individuals. Pathogenesis of H. pylori infection is based on the long-term host to bacterial interaction and affected by the virulence factors of the bacterium, environmental and host factors (age, sex, blood type). Mucosal inflammation is the basic principle mechanism underlying the disease development in which tissue destruction may be initiated and maintained by both the bacterial toxins (CagA, VacA, LPS) and immune responses by the host. Immune evasion with bacterial modulation of host response affects the long-term host colonization. Colonization is also affected by urease and/or motility of the bacterium, presence of lipopolysaccharide (LPS) and various bacterial enzymes. Gastric mucosal atrophy and intestinal metaplasia can develop during the course of H. pylori infection predisposing to carcinogenesis. Host cytokine gene polymorphism would be the one explanation for host susceptibility to peptic ulcer or gastric cancer. Investigation into the pathogenesis of H. pylori related diseases could provide an answer to the impact of chronic host to microbial interaction resulting human diseases.
Gastrointestinal Diseases ; Helicobacter Infections/microbiology/*physiopathology ; *Helicobacter pylori/physiology ; Humans

No abstract available
Cardiovascular Diseases/*microbiology/physiopathology ; Helicobacter Infections/*complications ; *Helicobacter pylori ; Humans

Considering the World Health Organization's classification of Helicobacter pylori as a definite (class I ) carci- nogen, the relationship between oral microbial community and tumors is gaining increased interest. This review focused on three relationships between oral microbiota and tumors, i.e., between oral Helicobacter pylori infection and gastric tumors, between oral microbiota and oral squamous cell carcinoma, and between human immunodeficiency virus and tumors. The aims were to realize the early diagnosis of tumors with oral microbiota and support studies on treatment development.
Helicobacter Infections ; Helicobacter pylori ; Humans ; Mouth ; microbiology ; Mouth Neoplasms

Helicobacter pylori (H. pylori) undergoes decades long colonization of the gastric mucosa of half the population in the world to produce acute and chronic gastritis at the beginning of infection, progressing to more severe disorders, including peptic ulcer disease and gastric cancer. Prolonged carriage of H. pylori is the most crucial factor for the pathogenesis of gastric maladies. Bacterial persistence in the gastric mucosa depends on bacterial factors as well as host factors. Herein, the host and bacterial components responsible for the incipient stages of H. pylori infection are reviewed and discussed. Bacterial adhesion and adaptation is presented to explain the persistence of H. pylori colonization in the gastric mucosa, in which bacterial evasion of host defense systems and genomic diversity are included.
Gastric Mucosa/*microbiology ; Gastritis/*microbiology/pathology ; Helicobacter Infections/*microbiology ; Helicobacter pylori/*physiology ; Humans ; Stomach Neoplasms/pathology

The relationship between Helicobacter pylori (H. pylori) infection and gastro-esophageal reflux disease (GERD) is complex. Since some studies have suggested that H. pylori eradication may result in an increased incidence of GERD in duodenal ulcer patients, there have been debates about the protective function of H. pylori infection on GERD. H. pylori-associated antral gastritis can induce increased gastric acid output via increasing gastrin secretion. Changes in gastric acid secretion depend on the distribution (e.g. antral, corpus or pangastritis) or severity of gastritis, not on H. pylori infection itself. Patients with H. pylori infection are at risk of developing gastric mucosal atrophy, and a cohort study suggested that long-term proton pump inhibitor therapy for GERD may accelerate this process. Therefore, it has been recommended that H. pylori should be treated in GERD patients in whom a long-term antisecretory therapy is planned. The previous hypothesis that 'H. pylori infection protects from the development of GERD' is thought to be an erroneous concept recently.
Gastritis/microbiology ; Gastroesophageal Reflux/drug therapy/*microbiology ; Helicobacter Infections/*complications/drug therapy ; *Helicobacter pylori ; Humans

Inflammatory bowel disease (IBD) is a non-specific inflammatory disease of the gastrointestinal (GI) tract that is generally accepted to be closely related to intestinal dysbiosis in the host. GI infections contribute a key role in the pathogenesis of IBD; however, although the results of recent clinical studies have revealed an inverse correlation between Helicobacter pylori (H. pylori) infection and IBD, the exact mechanism underlying the development of IBD remains unclear. H. pylori, as a star microorganism, has been a focus for decades, and recent preclinical and real-world studies have demonstrated that H. pylori not only affects the changes in the gastric microbiota and microenvironment but also influences the intestinal microbiota, indicating a potential correlation with IBD. Detailed analysis revealed that H. pylori infection increased the diversity of the intestinal microbiota, reduced the abundance of Bacteroidetes, augmented the abundance of Firmicutes, and produced short-chain fatty acid-producing bacteria such as Akkermansia. All these factors may decrease vulnerability to IBD. Further studies investigating the H. pylori-intestinal microbiota metabolite axis should be performed to understand the mechanism underlying the development of IBD.
Chronic Disease ; Dysbiosis/microbiology* ; Gastrointestinal Microbiome ; Helicobacter Infections ; Helicobacter pylori ; Humans ; Inflammatory Bowel Diseases/microbiology* ; Microbiota

Kyoto global consensus report on Helicobacter pylori gastritis (Gut, July 2015) is another important international consensus since the European Maastricht Ⅳ consensus was published. Kyoto consensus will improve the etiology-based classification, the diagnostic assessment of gastritis, and the treatment of H. pylori-associated dyspepsia and H. pylori gastritis. However, because of high rate of H. pylori infection and antibiotic resistance as well as limited health resources in China, we need to develop our own strategies of H. pylori infection control with the reference of the Kyoto global consensus.
China ; Consensus ; Dyspepsia ; microbiology ; therapy ; Gastritis ; microbiology ; therapy ; Helicobacter Infections ; therapy ; Helicobacter pylori ; Humans

Helicobacter pylori (Hp) is a high prevalence of chronic infectious pathogens, though not necessarily lead to symptoms, but it can affect the immune system. More than of the world's population harbors the bacterium, and most adult Hp infection was obtained in childhood. Hp infection is a major cause of peptic ulcer, although children rarely suffer from peptic ulcer disease. Hp infection is closely related to chronic gastritis, dyspepsia, chronic diarrhea and recurrent abdominal pain in children. In recent years, Hp infection may also participate in some of non-digestive diseases, such as children's nutritional iron deficiency anemia, growth retardation, malnutrition, autoimmune idiopathic thrombocytopenic purpura, chronic urticaria, as well as the development of adult atherosclerosis-related cardiovascular diseases and some nervous system diseases. Hp infection can be a lifetime issues of children. Hp infection of children will bring many socio-economic problems. In this paper, the correlation of Hp infection in stomach and oral cavity, and diagnostic technology, prevention as well as treatment strategies for Hp infection will be discussed.
Helicobacter Infections ; complications ; diagnosis ; epidemiology ; genetics ; Helicobacter pylori ; Humans ; Mouth ; microbiology ; Stomach ; microbiology

OBJECTIVES: The significance of the coccoid forms of H. pylori is still controversial and the questions of whether these forms are viable and infective or degenerative are still open. We induced conversion from rod to coccoid forms and studied morphological changes and antigenic evolutions during this conversion and, thereby, elucidated the viability of coccoid forms. METHODS: The H. pylori strain (C001) used for Western blotting was isolated from the patient with gastric cancer. The antigenic evolution during coccoid conversion of H. pylori was studied by Western blotting, using different sera from thirty patients known to be culture positive. These sera were used to reveal the total antigens of the strain cultured for 2 days (100% rod) and 15 days (> 99% coccoid). After SDS-PAGE, with 10% separating gel of total antigens (rod and coccoid), transblotting (Trans-Blot electrophoretic cell, Bio-Rad) was taken onto a nitrocellulose membrane (Bio-Rad). Then, the blots, with human sera diluted at 1/100, were developed with color reaction by goat serum anti-human IgG with alkaline phosphatase and BCIP. RESULTS: The antigenic profiles were not changed in 46.7% (14/30 cases) and were changed in 53.3% (16/30 cases) during coccoid conversion. Antigenic fractions changed during coccoid conversion were protein band at 120 kDa and band at 35 kDa, and were not detected in coccus forms. The rest of the profiles were identical between rod and coccoid forms. The protein which disappeared include CagA (120 kDa) and porin, or adhesin (35 kDa). The morphological changes during coccoid conversion were U shaped at day 7, doughnut shaped at day 9 and full coccoid at day 15. CONCLUSIONS: The results showed that coccoid forms of H. pylori retain cellular structures similar to rod form, and some of the antigens (CagA and porin) disappeared during coccoid conversion. Therefore, coccoid form might be viable and represent one of the stages of H. pylori biological cycle.
Adaptation, Physiological ; Antigens, Bacterial/isolation & purification* ; Gastritis/microbiology ; Helicobacter Infections/microbiology ; Helicobacter pylori/ultrastructure* ; Helicobacter pylori/immunology* ; Helicobacter pylori/growth & development ; Human ; Microscopy, Electron ; Stomach Neoplasms/microbiology ; Virulence