The Effects of Helicobacter pylori Infection on Microbiota Associated With Gastric Mucosa and Immune Factors in Children

Human gastric microbiota analysis of refractory H. pylori infection

H. pylori infection is gaining increasing attention, but detailed investigations into its impact on gastric microbiota remain limited. We collected gastric mucosa samples from 47 individuals divided into three groups: 1. Group HP: patients with initial positive H. pylori infection (25 cases); 2. Group ck: H. pylori-negative patients (14 cases); 3. Group DiffHP: patients with refractory H. pylori infection (8 cases). The samples were analyzed using 16S rDNA sequencing and functional prediction with PICRUSt. Group HP showed differences in flora distribution and function compared to Group ck, while Group DiffHP overlapped with Group HP. The abundances of Aeromonas piscicola, Shewanella algae, Vibrio plantisponsor, Aeromonas caviae, Serratia marcescens, Vibrio parahaemolyticus, Microbacterium lacticum, and Prevotella nigrescens were significantly reduced in both Group DiffHP and Group HP compared to Group ck. Vibrio shilonii was reduced only in Group DiffHP compared to Group ck, while Clostridium perfringens and Paracoccus marinus were increased only in Group DiffHP. LEfSe analysis revealed that Clostridium perfringens and Paracoccus marinus were enriched, whereas Vibrio shilonii was reduced in Group DiffHP compared to Group ck at the species level. In individuals with refractory H. pylori infection, the gastric microbiota exhibited enrichment in various human diseases, organic systems, and metabolic pathways (amino acid metabolism, carbohydrate metabolism, transcription, replication and repair, cell cycle pathways, and apoptosis). Patients with multiple failed H. pylori eradication exhibited significant changes in the gastric microbiota. An increase in Clostridium perfringens and Paracoccus marinus and a decrease in Vibrio shilonii appears to be characteristic of refractory H. pylori infection.

Helicobacter pylori infection alters gastric microbiota structure and biological functions in patients with gastric ulcer or duodenal ulcer

BACKGROUND

Helicobacter pylori (H. pylori) infection is closely associated with gastrointestinal diseases. Our preliminary studies have indicated that H. pylori infection had a significant impact on the mucosal microbiome structure in patients with gastric ulcer (GU) or duodenal ulcer (DU).

AIM

To investigate the contributions of H. pylori infection and the mucosal microbiome to the pathogenesis and progression of ulcerative diseases.

METHODS

Patients with H. pylori infection and either GU or DU, and healthy individuals without H. pylori infection were included. Gastric or duodenal mucosal samples was obtained and subjected to metagenomic sequencing. The compositions of the microbial communities and their metabolic functions in the mucosal tissues were analyzed.

RESULTS

Compared with that in the healthy individuals, the gastric mucosal microbiota in the H. pylori-positive patients with GU was dominated by H. pylori, with significantly reduced biodiversity. The intergroup differential functions, which were enriched in the H. pylori-positive GU patients, were all derived from H. pylori, particularly those concerning transfer RNA queuosine-modification and the synthesis of demethylmenaquinones or menaquinones. A significant enrichment of the uibE gene was detected in the synthesis pathway. There was no significant difference in microbial diversity between the H. pylori-positive DU patients and healthy controls.

CONCLUSION

H. pylori infection significantly alters the gastric microbiota structure, diversity, and biological functions, which may be important contributing factors for GU.

Simultaneous application of oral and intravaginal probiotics for Helicobacter pylori and its antibiotic-therapy-induced vaginal dysbacteriosis

Helicobacter pylori is a prevalent bacterial pathogen globally, implicated in various gastrointestinal disorders. Current recommended antibiotic therapies for H. pylori infection have been proven to be therapeutically insufficient, with low eradication rates and high recurrence rates. Emerging evidence suggests that antibiotic therapy for H. pylori can lead to gastrointestinal and subsequent vaginal dysbiosis, posing challenges for conventional antibiotic approaches. Thus, this article proposes a novel probiotic therapy involving simultaneous oral and intra-vaginal probiotic administration alongside antibiotics for H. pylori treatment, aiming to enhance eradication rates and mitigate dysbiosis. We begin by providing an overview of gastrointestinal and vaginal microbiota and their interconnectedness through the vagina-gut axis. We then review the efficacy of current antibiotic regimens for H. pylori and discuss how antibiotic treatment impacts the vaginal microenvironment. To explore the feasibility of this approach, we evaluate the effectiveness of oral and intra-vaginal probiotics in restoring normal microbiota in the gastrointestinal and vaginal tracts, respectively. Additionally, we analyze the direct mechanisms by which oral and intra-vaginal probiotics act on their respective tracts and discuss potential cross-tract mechanisms. Considering the potential synergistic therapeutic effects of probiotics in both the gastrointestinal and vaginal tracts, dual-channel probiotic therapy holds promise as a more effective approach for H. pylori eradication and dysbiosis mitigation, presenting a novel concept in the collaborative treatment of gastrointestinal and genital disorders.

A review for non-antibiotic treatment of Helicobacter pylori: new insight

Gastric ulcers and gastric cancer are brought on by the Helicobacter pylori bacteria, which colonizes under the stomach mucous membrane. Different medication regimens are used to remove it, but the illness returns and becomes more resistant, which lowers the treatment rates. Additionally, this bacterium now exhibits a skyrocketing level of multi-drug resistance, necessitating recurrent therapeutic treatments. The negative effects of synthetic medications in comparison to conventional therapies are another significant factor in favor of non-pharmacological therapy. The most significant side effects of popular anti-gastric ulcer medications include nausea, vomiting, and diarrhea. Stomach ulcers have previously been treated with herbal remedies and complementary treatments like probiotics. When probiotics are ingested, the host experiences several advantages that may be brought about by altering the bacterial flora in the digestive system. Additionally, stronger-acting chemical compounds and plant extracts can be employed to treat patients. In this article, we look at the substances and medications that are utilized in place of synthetic stomach ulcer-curing treatments.

Helicobacter pylori causes gastric dysbacteriosis in chronic gastritis patients

Gastric mucosal samples were procured and underwent the sequencing of 16S ribosomal RNA (16S rRNA) via Illumina high-throughput sequencing technology to explore the impact of Helicobacter pylori (H. pylori) infection on the composition of gastric flora in chronic gastritis (CG) patients. In the results, the operational taxonomic unit (OTU) analysis revealed an overlap of 5706 OTUs shared between the two groups. The top 5 abundance ranking (TOP5) phyla comprised Bacteroidetes, Proteobacteria, Firmicutes, Actinobacteria, and Epsilonbacteraeota, while the TOP5 genus was Lachnospiraceae_NK4A136_group, Helicobacter, Bacteroides, Klebsiella, and Pseudomonas. In the metabolic pathways at the Kyoto Encyclopedia of Genes and Genomes (KEGG)_L3 level, conspicuous variations across seven functions were observed between the H. pylori-positive (HP_Pos) and H. pylori-negative (HP_Neg) groups. Subsequently, functional gene enrichment in KEGG pathways was further validated through animal experimentation. In contrast to the mice in the HP_Neg group, those infected with H. pylori manifested an infiltration of inflammatory cells, an augmentation in gastric acid secretion, and conspicuously elevated scores regarding gastric activity, along with heightened levels of malondialdehyde. In conclusion, CG patients infected with H. pylori displayed a disorder in gastric flora, furnishing a theoretical basis for the prophylaxis of H. pylori infection and its associated pathogenic ramifications.

Update on the association between Helicobacter pylori infection and asthma in terms of microbiota and immunity

H. pylori is a gram-negative bacterium that is usually acquired in childhood and can persistently colonize the gastric mucosa of humans, affecting approximately half of the world's population. In recent years, the prevalence of H. pylori infection has steadily reduced while the risk of allergic diseases has steadily climbed. As a result, epidemiological research indicates a strong negative association between the two. Moreover, numerous experimental studies have demonstrated that eradicating H. pylori increases the risk of allergic diseases. Hence, it is hypothesized that H. pylori infection may act as a safeguard against allergic diseases. The hygiene hypothesis, alterations in gut microbiota, the development of tolerogenic dendritic cells, and helper T cells could all be involved in H. pylori's ability to protect against asthma. Furthermore, Studies on mice models have indicated that H. pylori and its extracts are crucial in the management of asthma. We reviewed the in-depth studies on the most recent developments in the relationship between H. pylori infection and allergic diseases, and we discussed potential mechanisms of the infection's protective effect on asthma in terms of microbiota and immunity. We also investigated the prospect of the application of H. pylori and its related components in asthma, so as to provide a new perspective for the prevention or treatment of allergic diseases.

Review of Phytochemical Potency as a Natural Anti-Helicobacter pylori and Neuroprotective Agent

Phytochemicals are plant secondary metabolites that show health benefits for humans due to their bioactivity. There is a huge variety of phytochemicals that have already been identified, and these compounds can act as antimicrobial and neuroprotection agents. Due to their anti-microbial activity and neuroprotection, several phytochemicals might have the potency to be used as natural therapeutic agents, especially for Helicobacter pylori infection and neurodegenerative disease, which have become a global health concern nowadays. According to previous research, there are some connections between H. pylori infection and neurodegenerative diseases, especially Alzheimer's disease. Hence, this comprehensive review examines different kinds of phytochemicals from natural sources as potential therapeutic agents to reduce H. pylori infection and improve neurodegenerative disease. An additional large-scale study is needed to establish the connection between H. pylori infection and neurodegenerative disease and how phytochemicals could improve this condition.

Gastric juice microbiota in pediatric chronic gastritis that clinically tested positive and negative for Helicobacter pylori

Purpose

Helicobacter pylori (HP) infection is an identified risk factor for pediatric chronic gastritis (PCG), but its impact on gastric juice microbiota (GJM) remains to be further elucidated in PCG. This study aimed to analyze and compare the microbial communities and microbial interactive networks of GJM in PCG that clinically tested positive and negative for HP (HP+ and HP-, respectively).

Methods

A total of 45 PCG patients aged from 6 to 16 years were recruited, including 20 HP+ and 25 HP- patients tested by culture and rapid urease test. Gastric juice samples were collected from these PCG patients and subjected to high-throughput amplicon sequencing and subsequent analysis of 16S rRNA genes.

Results

While no significant change in alpha diversity, significant differences in beta diversity were observed between HP+ and HP- PCG. At the genus level, Streptococcus, Helicobacter, and Granulicatella were significantly enriched in HP+ PCG, whereas Campylobacter and Absconditabacteriales (SR1) were significantly enriched in HP- PCG. Network analysis showed that Streptococcus was the only genus positively correlated with Helicobacter (r = 0.497) in the GJM network of overall PCG. Moreover, compared to HP- PCG, HP+ PCG showed a reduction in microbial network connectivity in GJM. Netshift analysis identified driver microbes including Streptococcus and other four genera, which substantially contributed to the GJM network transition from HP- PCG to HP+ PCG. Furthermore, Predicted GJM function analysis indicated up-regulated pathways related to the metabolism of nucleotides, carbohydrates, and L-Lysine, the urea cycle, as well as endotoxin peptidoglycan biosynthesis and maturation in HP+ PCG.

Conclusion

GJM in HP+ PCG exhibited dramatically altered beta diversity, taxonomic structure, and function, with reduced microbial network connectivity, which could be involved in the disease etiology.

The Influence of Helicobacter pylori on Human Gastric and Gut Microbiota

Helicobacter pylori is a Gram-negative bacterium that is able to colonize the human stomach, whose high prevalence has a major impact on human health, due to its association with several gastric and extra-gastric disorders, including gastric cancer. The gastric microenvironment is deeply affected by H. pylori colonization, with consequent effects on the gastrointestinal microbiota, exerted via the regulation of various factors, including gastric acidity, host immune responses, antimicrobial peptides, and virulence factors. The eradication therapy required to treat H. pylori infection can also have detrimental consequences for the gut microbiota, leading to a decreased alpha diversity. Notably, therapy regimens integrated with probiotics have been shown to reduce the negative effects of antibiotic therapy on the gut microbiota. These eradication therapies combined with probiotics have also higher rates of eradication, when compared to standard treatments, and are associated with reduced side effects, improving the patient's compliance. In light of the deep impact of gut microbiota alterations on human health, the present article aims to provide an overview of the complex interaction between H. pylori and the gastrointestinal microbiota, focusing also on the consequences of eradication therapies and the effects of probiotic supplementation.

Gastric microbiota dysbiosis and Helicobacter pylori infection

Helicobacter pylori (H. pylori) infection is one of the most common causes of gastric disease. The persistent increase in antibiotic resistance worldwide has made H. pylori eradication challenging for clinicians. The stomach is unsterile and characterized by a unique niche. Communication among microorganisms in the stomach results in diverse microbial fitness, population dynamics, and functional capacities, which may be positive, negative, or neutral. Here, we review gastric microecology, its imbalance, and gastric diseases. Moreover, we summarize the relationship between H. pylori and gastric microecology, including non-H. pylori bacteria, fungi, and viruses and the possibility of facilitating H. pylori eradication by gastric microecology modulation, including probiotics, prebiotics, postbiotics, synbiotics, and microbiota transplantation.

Bile reflux alters the profile of the gastric mucosa microbiota

Background

Bile reflux can cause inflammation, gastric mucosa atrophy, and diseases such as stomach cancer. Alkaline bile flowing back into the stomach affects the intragastric environment and can alter the gastric bacterial community. We sought to identify the characteristics of the stomach mucosal microbiota in patients with bile reflux.

Methods

Gastric mucosal samples were collected from 52 and 40 chronic gastritis patients with and without bile reflux, respectively. The bacterial profile was determined using 16S rRNA gene analysis.

Results

In the absence of H. pylori infection, the richness (based on the Sobs and Chao1 indices; P <0.05) and diversity (based on Shannon indices; P <0.05) of gastric mucosa microbiota were higher in patients with bile reflux patients than in those without. There was a marked difference in the microbiota structure between patients with and without bile reflux (ANOSIM, R=0.058, P=0.011). While the genera, Comamonas, Halomonas, Bradymonas, Pseudomonas, Marinobacter, Arthrobacter, and Shewanella were enriched in patients with bile reflux, the genera, Haemophilus, Porphyromonas, and Subdoligranulum, were enriched in those without bile reflux.

Conclusion

Our results demonstrate that bile reflux significantly alters the composition of the gastric microbiota.

Convergent dysbiosis of gastric mucosa and fluid microbiome during stomach carcinogenesis

BACKGROUND

A complex microbiota in the gastric mucosa (GM) has been unveiled recently and its dysbiosis is identified to be associated with gastric cancer (GC). However, the microbial composition in gastric fluid (GF) and its correlation with GM during gastric carcinogenesis are unclear.

METHODS

We obtained GM and GF samples from 180 patients, including 61 superficial gastritis (SG), 55 intestinal metaplasia (IM) and 64 GC and performed 16S rRNA gene sequencing analysis. The concentration of gastric acid and metabolite nitrite has been measured.

RESULTS

Overall, the composition of microbiome in GM was distinct from GF with less diversity, and both were influenced by H. pylori infection. The structure of microbiota changed differentially in GM and GF across histological stages of GC, accompanied with decreased gastric acid and increased carcinogenic nitrite. The classifiers of GC based on microbial markers were identified in both GM and GF, including Lactobacillus, Veillonella, Gemella, and were further validated in an independent cohort with good performance. Interestingly, paired comparison between GM and GF showed that their compositional distinction remarkably dwindled from SG to GC, with some GF-enriched bacteria significantly increased in GM. Moreover, stronger interaction network between microbes of GM and GF was observed in GC compared to SG.

CONCLUSION

Our results, for the first time, revealed a comprehensive profile of both GM and GF microbiomes during the development of GC. The convergent microbial characteristics between GM and GF in GC suggest that the colonization of carcinogenic microbes in GM might derive from GF.

SHP2/SPI1axis promotes glycolysis and the inflammatory response of macrophages in Helicobacter pylori-induced pediatric gastritis

BACKGROUND

Macrophages, as innate immune cells, were reported to participate in the pathogenesis of Helicobacter pylori (H. pylori)-induced gastritis. However, the role and mechanism of macrophage dysfunction in H. pylori-associated pediatric gastritis remain unclear.

MATERIALS AND METHODS

An RNA-sequencing assay was used to examine the differential gene expression in normal gastric antrum, non-H. pylori-infected tissue, and H. pylori-infected pediatric gastritis tissue. qPCR assays were applied to verify the expression of target genes. HE staining was performed to identify the occurrence of inflammation in the normal gastric antrum, non-H. pylori-infected tissue, and H. pylori-infected pediatric gastritis tissue. Western blotting was used to measure the expression of SHP2 in pediatric gastritis tissue. The metabolic profile of macrophages was determined via Seahorse metabolic analysis. Flow cytometry analysis was used to examine the level of reactive oxygen species (ROS).

RESULTS

We found that H. pylori -infected gastritis tissue exhibited many differentially expressed genes (DEGs) compared to gastritis tissue without H. pylori infection. Moreover, H. pylori -infected gastritis tissue showed many DEGs annotated with an overactive immune response. We identified that tyrosine-protein phosphatase nonreceptor type 11 (PTPN11), which encodes SHP2, was significantly increased in macrophages of H. pylori -infected gastritis tissue. Furthermore, we revealed that SHP2 could activate the glycolytic function of macrophages to promote H. pylori -induced inflammation. The transcription factor SPI1 , as the downstream molecule of SHP2, could be responsible for the regulation of metabolism-associated gene expression and inflammation.

CONCLUSION

Our study illustrated the molecular landscape of H. pylori-infected gastritis tissue in children and suggested that the SHP2/SPI1axis could be a novel therapeutic target in H. pylori-induced pediatric gastritis.

The Effects of Helicobacter pylori Infection on Gastric Microbiota in Children With Duodenal Ulcer

Background

Helicobacter pylori (H. pylori) infection is the main cause of chronic gastritis and duodenal ulcer in children. Little is known about the effect of H. pylori on gastric microbiota in children with duodenal ulcer. This study is aimed at the characteristics of gastric microbiota in children with duodenal ulcer on H. pylori infection.

Methods

We studied 23 children diagnosed with duodenal ulcer by gastric endoscopy because of the gastrointestinal symptoms, 15 children were diagnosed with H. pylori infection, while 8 children were without H. pylori infection. Endoscopic mucosal biopsy samples were obtained for DNA extraction. Microbiomes were analyzed by 16S rRNA profiling and microbial functions were predicted using the software Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt).

Results

Bacterial richness and diversity of gastric microbiota in duodenal ulcer with H. pylori-positive were lower than those negative. The gastric microbiota in H. pylori-positive group significantly reduced proportions of six phyla and fifteen genera; only Helicobacter taxa were more abundant in H. pylori-positive group. Co-expression network analysis showed a more complex network of interactions in the H. pylori-positive group than that in the H. pylori-negative group. For the predicted functions, lower abundance in the pathways of carbohydrate metabolism, signal transduction, amino acid metabolism, and lipid metabolism were found in H. pylori-positive group than the H. pylori-negative group. H. pylori colonization reduces a microbial community with genotoxic potential in the gastric mucosa of children with duodenal ulcer.

Conclusions

The presence of H. pylori significantly influences gastric microbiota and results in a lower abundance of multiple taxonomic levels in children with duodenal ulcer. Children with duodenal ulcer exhibit a dysbiotic microbial community with genotoxic potential, which is distinct from that of children with H. pylori infection.

Clinical Trial Registration

[http://www.chictr.org.cn], identifier [ChiCTR1800015190].

Induction and Regulation of the Innate Immune Response in Helicobacter pylori Infection

Gastric cancer (GC) is the fifth most common cancer and the fourth most common cause of cancer-related death worldwide. The intestinal type of GC progresses from acute to chronic gastritis, multifocal atrophic gastritis, intestinal metaplasia, dysplasia, and carcinoma. Infection of the stomach by Helicobacter pylori, a Gram-negative bacterium that infects approximately 50% of the world's population, is the causal determinant that initiates the gastric inflammation and then disease progression. In this context, the induction of the innate immune response of gastric epithelial cells and myeloid cells by H. pylori effectors plays a critical role in the outcome of the infection. However, only 1% to 3% of infected patients develop gastric adenocarcinoma, emphasizing that other mechanisms regulate the localized non-specific response, including the gastric microbiota and genetic factors. This review summarizes studies describing the factors that induce and regulate the mucosal innate immune response during H. pylori infection.