Culturable Bacterial Microbiota of the Stomach of Helicobacter pylori Positive and Negative Gastric Disease Patients

Human stomach is the only known natural habitat of Helicobacter pylori (Hp), a major bacterial pathogen that causes different gastroduodenal diseases. Despite this, the impact of Hp on the diversity and the composition of the gastric microbiota has been poorly studied. In this study, we have analyzed the culturable gastric microbiota of 215 Malaysian patients, including 131 Hp positive and 84 Hp negative individuals that were affected by different gastric diseases. Non-Hp bacteria isolated from biopsy samples were identified by matrix assisted laser desorption ionization-time of flight mass spectrometry based biotyping and 16SrRNA sequencing. The presence of Hp did not significantly modify the diversity of the gastric microbiota. However, correlation was observed between the isolation of Streptococci and peptic ulcer disease. In addition, as a first report, Burkholderia pseudomallei was also isolated from the gastric samples of the local population. This study suggested that there may be geographical variations in the diversity of the human gastric microbiome. Geographically linked diversity in the gastric microbiome and possible interactions between Hp and other bacterial species from stomach microbiota in pathogenesis are proposed for further investigations

Polymorphisms in the host CYP2C19 gene and antibiotic-resistance attributes of Helicobacter pylori isolates influence the outcome of triple therapy

Objectives: Eradication of Helicobacter pylori is influenced by susceptibility to antimicrobial agents, elevated bacterial load and degree of acid inhibition, which can be affected by genotypes of drug-metabolizing enzymes [cytochrome P450 (CYP) 2C19 polymorphism]. Theoretically, the choice and dose of proton pump inhibitor may also influence the suppression of H. pylori infection. The CYP2C19 genotype has recently been found to have an impact on peptic ulcer healing, H. pylori eradication and therapeutic efficacy of proton pump inhibitors. Methods: Here, we investigated the impact of the CYP2C19 genotype polymorphism and the success of triple therapy (fluoroquinolones/metronidazole/clarithromycin) on antibiotic-resistant strains in eradicating H. pylori in human subjects with non-ulcer dyspepsia (NUD), in human subjects with peptic ulcer disease (PUD) and in asymptomatic human subjects (positive and negative for H. pylori infection). Results: Based on the CYP2C19 genotypes, determined by Droplet Digital PCR (ddPCR) analysis, we found 11.2%, 62.5% and 26.3% corresponding to rapid metabolizers, intermediate metabolizers and poor metabolizers, respectively. However, we did not find any significant effect for homozygous ABCB1 or CYP2C19*2 and CYP2C19*3 alleles. We detected several participants heterozygous for both ABCB1 and CYP2C19*2, CYP2C19*3 and CYP2C19*17 loci. The participants heterozygous for both ABCB1 and CYP2C19*2 and *3 loci should be defined as intermediate and poor metabolizers according to the haplotype analysis in the NUD, PUD and asymptomatic subjects. Conclusions: Consequently, fluoroquinolones/metronidazole/clarithromycin-based triple therapies can be used to eradicate H. pylori infection, if one does not know the CYP2C19 genotype of the patient

Changes in Metabolic Hormones in Malaysian Young Adults following Helicobacter pylori Eradication.

More than half of the world's adults carry Helicobacter pylori. The eradication of H. pylori may affect the regulation of human metabolic hormones. The aim of this study was to evaluate the effect of H. pylori eradication on meal-associated changes in appetite-controlled insulinotropic and digestive hormones, and to assess post-eradication changes in body mass index as part of a currently on-going multicentre ESSAY (Eradication Study in Stable Adults/Youths) study.We enrolled 29 H. pylori-positive young adult (18-30 year-old) volunteer subjects to evaluate the effect of H. pylori eradication on meal-associated changes on eight gastrointestinal hormones, using a multiplex bead assay. Changes in body mass index and anthropometric measurements were recorded, pre- and post-eradication therapy.Pre-prandial active amylin, total peptide YY (PYY) and pancreatic polypeptide (PP) levels were significantly elevated 12 months post-eradication compared with baseline (n = 18; Wilcoxon's signed rank test, p<0.05). Four of the post-prandial gut metabolic hormones levels (GLP-1, total PYY, active amylin, PP) were significantly higher 12 months post-eradication compared to baseline (n = 18; p<0.05). Following H. pylori eradication, the BMI and anthropometric values did not significantly change.Our study indicates that H. pylori eradication was associated with long-term disturbance in three hormones (active amylin, PP and total PYY) both pre- and post-prandially and one hormone (GLP-1) post-prandially. Longer post-eradication monitoring is needed to investigate the long-term impact of the observed hormonal changes on metabolic homeostasis

Boxplot analysis of single nucleotide polymorphism (A) TLR-1 <i>rs4833095</i> and (B) TLR-10 <i>rs10004195</i> in gastroduodenal diseases and gastric cancer (GC).

<p>Single nucleotide polymorphism TLR-1 <i>rs4833095</i> and TLR-10 <i>rs10004195</i> were measured using ddPCR. Data were from three independent experiments. Level of significance set at p<0.05. (Note: ddPCR, digital droplet polymerase chain reaction)</p

Distribution (mean and standard deviation) of gut hormones and its cognate receptors and pro-inflammatory cytokine concentrations based on age subgroups.

<p>†Significant correlation</p><p>Distribution (mean and standard deviation) of gut hormones and its cognate receptors and pro-inflammatory cytokine concentrations based on age subgroups.</p

Whiskers plot analysis of distribution of plasma immunoreactive gut hormones (A) Leptin (B) Leptin receptor (C) Ghrelin (D) Ghrelin receptor (E) pro-inflammatory cytokine concentrations (TNF-α, IFN-γ, IL-8) in gastroduodenal diseases and gastric cancer (GC).

<p>Plasma leptin, leptin receptor, ghrelin, ghrelin receptor, TNF-α, IFN-γ and IL-8 concentrations measured using commercial double-antibody sandwich ELISA. Data were from three independent experiments. Level of significance set at p<0.05. (Note: IL, interleukin; IFN-γ, interferon gamma; TNF-α, tumor necrosis factor alpha)</p

Hematoxylin & Eosin (H & E) histopathological investigations on gastric antrum and corpus mucosal tissues of individuals with different gastroduodenal diseases and gastric cancer (GC) positive and negative for <i>H</i>. <i>pylori</i> infection.

<p>(A & B) Antrum tissue showing chronic changes with mild glandular atrophy (Magnification: 100X). (<b>C</b>) Corpus tissue showing signs of chronic active gastritis with mild chronic inflammatory activity and moderate active inflammation. There is moderate infiltration of neutrophils (arrow) (Magnification: 100X). (<b>D</b>) Antrum tissue showing chronic active gastritis with marked chronic inflammatory activity. There is marked infiltration of plasma cells and lymphocytes (arrow) (Magnification: 100X). (<b>E</b>) Antrum tissues showing chronic active gastritis with marked chronic inflammatory activity and superimposed moderate active inflammation. There is moderate glandular atrophy and intestinal metaplasia. There is infiltration of eosinophils (arrow) (Magnification: 100X). (<b>F</b>) Antrum tissue showing marked intestinal metaplasia with goblet cell change (Magnification: 100X). (<b>G</b>) Gastric tissue with <i>H</i>. <i>pylori</i> (arrow) (Magnification: 400X).</p

Demographic and laboratory characteristics of the study population. Numbers in parentheses indicate percentage.

<p>Demographic and laboratory characteristics of the study population. Numbers in parentheses indicate percentage.</p