Helicobacter pylori in Inflammatory Bowel Diseases: Active Protagonist or Innocent Bystander?

Helicobacter pylori (H. pylori) infection is a prominent entity within human infectious diseases which cause chronic gastritis, peptic ulcers, gastric malignancies, and extragastric disorders. Its persistent colonization can lead to a systemic inflammatory cascade, potentially instigating autoimmune responses and contributing to the pathogenesis of autoimmune diseases. While the specific etiopathogenesis of inflammatory bowel diseases (IBDs) is still unknown, it is widely recognized that immunological, genetic, and environmental factors are implicated. Various bacterial and viral pathogens have been implicated in the pathogenesis of IBDs. Numerous studies suggest a correlation between H. pylori infection and IBDs. While subject to debate, this link suggests that the bacterium's presence somehow impacts the progression of IBDs by modifying the diversity of the gut microbiota, consequently altering local chemical profiles and disrupting the pattern of gut immune response. However, epidemiological evidence indicates a protective role of H. pylori infection against the onset of autoimmune diseases. Additionally, laboratory findings demonstrate H. pylori's capacity to promote immune tolerance and restrict inflammatory reactions. The aim of this review is to elucidate the proposed mechanisms and confounding factors that underlie the potential association between H. pylori infection and IBDs.

Sustained exposure to Helicobacter pylori induces immune tolerance by desensitizing TLR6

Helicobacter pylori (H. pylori, Hp) has been designated a class I carcinogen and is closely associated with severe gastric diseases. During colonization in the gastric mucosa, H. pylori develops immune escape by inducing host immune tolerance. The gastric epithelium acts as the first line of defense against H. pylori, with Toll-like receptors (TLRs) in gastric epithelial cells being sensitive to H. pylori components and subsequently activating the innate immune system. However, the mechanism of immune tolerance induced by H. pylori through the TLR signalling pathway has not been fully elucidated. In this research, we detected the expression of TLRs and inflammatory cytokines in GES-1 cells upon sustained exposure to H. pylori or H. pylori lysate from 1 to 30 generations and in Mongolian gerbils infected with H. pylori for 5 to 90 weeks. We found that the levels of TLR6 and inflammatory cytokines first increased and then dropped during the course of H. pylori treatment in vitro and in vivo. The restoration of TLR6 potentiated the expression of IL-1β and IL-8 in GES-1 cells, which recruited neutrophils and reduced the colonization of H. pylori in the gastric mucosa of gerbils. Mechanistically, we found that persistent infection with H. pylori reduces the sensitivity of TLR6 to bacterial components and regulates the expression of inflammatory cytokines in GES-1 cells through TLR6/JNK signaling. The TLR6 agonist obviously alleviated inflammation in vitro and in vivo. Promising results suggest that TLR6 may be a potential candidate immunotherapy drug for H. pylori infection.

Efficacy and tolerability of Helicobacter pylori eradication regimes in South Kivu, Eastern of the Democratic Republic of Congo: A single center observational study

Background and Aims

Treating Helicobacter pylori infections has become a major challenge due to increased antibiotic resistance. The aim of this study was to investigate the efficacy and tolerability of the main standard regimens recommended for H. pylori eradication in Bukavu, Eastern of the Democratic Republic of Congo.

Methods

The study enrolled patients with evidence of H. pylori infection in histological examination or serology testing combined with a positive fecal antigen test. As first-line treatment, patients were randomized to either a 10-days (OAC-10) or a 14-days (OAC-14) regimen, employing a combination of omeprazole 20 mg, amoxicillin 1 g, and clarithromycin 500 mg twice daily. In case of failure, a second line regimen was evaluated and included two others protocols: OAC-10 regimen + levofloxacin 500 mg (OAC-10+) and the bismuth-based therapy (pantoprazole + bismuth salt + metronidazole + tetracycline) during 10 days. Our primary endpoint was H. pylori eradication and secondarily, the compliance and adverse effects were also evaluated.

Results

A total of 179 patients were enrolled. The eradication rate was 79.2% and 80.5% with the OAC-10 and OAC-14 regimen, respectively (p = 0.796). Adverse effects were significant higher in the OAC-14 group than in the OAC-10 group (36.5% vs. 57.8%; p < 0.001). On the other hand, the compliance rate was slightly higher in the OAC-10 group (97.9% vs. 91.6%, p = 0.052) while clinical improvement was almost similar in both groups. Regarding the second line regimen, the bismuth-based therapy (n = 18) seemed to show a better response with 100% of eradication rate and 100% of clinical improvement.

Conclusion

The classic 10-days triple therapy seems to be as effective as the 14-days regimen while having in addition a good tolerance. Apart from cost issues, the bismuth-based therapy seems to be a very good alternative in case of first-line treatment failure.

An M cell-targeting recombinant L. lactis vaccine against four H. pylori adhesins

The acidic environment and enzyme degradation lead to oral vaccines often having little immune effect. Therefore, it is an attractive strategy to study an effective and safe oral vaccine delivery system that can promote gastrointestinal mucosal immune responses and inhibit antigen degradation. Moreover, the antigens uptake by microfold cells (M cells) is the determining step in initiating efficient immune responses. Therefore, M cell-targeting is one promising approach for enhancing oral vaccine potency. In the present study, an M cell-targeting L. lactis surface display system (plSAM) was built to favor the multivalent epitope vaccine antigen (FAdE) to achieve effective gastrointestinal mucosal immunity against Helicobacter pylori. Therefore, a recombinant Lactococcus lactic acid vaccine (LL-plSAM-FAdE) was successfully prepared, and its immunological properties and protective efficacy were analyzed. The results showed that LL-plSAM-FAdE can secretively express the recombinant proteins SAM-FAdE and display the SAM-FAdE on the bacterial cell surface. More importantly, LL-plSAM-FAdE effectively promoted the phagocytosis and transport of vaccine antigen by M cells in the gastrointestinal tract of mice, and simulated high levels of cellular and humoral immune responses against four key H. pylori adhesins (Urease, CagL, HpaA, and Lpp20) in the gastrointestinal tract, thus enabling effective prevention of H. pylori infection and to some extent eliminating H. pylori already present in the gastrointestinal tract. KEY POINTS: • M-cell-targeting L. lactis surface display system LL- plSAM was designed • This system displays H. pylori vaccine-promoted phagocytosis and transport of M cell • A promising vaccine candidate for controlling H. pylori infection was verified.

Predictors of Successful First-Line Helicobacter pylori Eradication with Fluoroquinolones in Pakistan: A Prospective Exploration of Demographic and Clinical Factors

Growing antibiotic resistance complicates H. pylori eradication, posing a public health challenge. Inconclusive research on sociodemographic and clinical factors emphasizes the necessity for further investigations. Hence, this study aims to evaluate the correlation between demographic and clinical factors and the success rates of H. pylori eradication. A group of 162 H. pylori-positive patients were allocated randomly to receive either a ten-day moxifloxacin-based triple therapy or a levofloxacin-based sequential therapy. Eradication success was determined through the stool antigen test. Logistic regression analysis was utilized to figure out potential factors that contribute to H. pylori eradication success. Significantly higher H. pylori eradication rates were observed in the middle age group (COR: 3.671, p = 0.007), among females (p = 0.035), those with BMI ≥ 25 (COR: 2.011, p = 0.045), and non-smokers (COR: 2.718, p = 0.018). In multivariate analysis, age and smoking emerged as significant predictors (p < 0.05). Patients with comorbidities, excluding diabetes and hypertension (COR: 4.432, p = 0.019), dyspepsia (COR: 0.178, p < 0.001), and moxifloxacin triple therapy (COR: 0.194, p = 0.000), exhibited higher chances of eradication (p < 0.05). Further research is vital for tailored approaches to enhance eradication success.

A population-based study of Helicobacter pylori: Does asymptomatic infection mean no gastroscopic lesions?

OBJECTIVES

We determined the common clinical characteristics of patients infected with Helicobacter pylori (H. pylori) and investigated the relationship between H. pylori infection, and clinical symptoms, and gastroscopic manifestations. Our focus was specifically on the clinical manifestations in asymptomatic patients.

METHODS

We obtained the physical examination data of patients who underwent the 14C urea breath test between January 2018 and December 2020 at our Hospital. Basic demographic data, questionnaire data on clinical symptoms, and clinical examination data of the patients were also collected, and the correlation analysis was performed.

RESULTS

A total of 2863 participants were included in the study. The overall H. pylori infection rate was 26.30%. The clinical symptoms between H. pylori-positive patients and H. pylori-negative patients did not differ significantly (P > .05). However, H. pylori-positive patients exhibited more severe gastroscopic manifestations (P < .001). The 14C urea breath test disintegrations per minute (DPM) values in H. pylori-positive patients correlated with their serum pepsinogen and gastrin-17 levels. With an increase in the DPM value, more combinations of clinical symptoms appeared in the patients. Among H. pylori-positive patients, DPM levels in asymptomatic patients were lower than those in symptomatic patients (P < .001). However, gastroscopic manifestations did not vary significantly between asymptomatic and symptomatic patients (P > .05).

CONCLUSION

Patients infected with H. pylori showed no specific gastrointestinal symptoms. Patients with asymptomatic infection showed lower DPM levels, but their gastroscopic manifestations were similar to those of patients with symptomatic infection, and their lesions were more severe than H. pylori-negative people.

Butyric Acid Supplementation Reduces Changes in the Taxonomic and Functional Composition of Gut Microbiota Caused by H. pylori Eradication Therapy

H. pylori eradication therapy leads to significant changes in the gut microbiome, including influence on the gut microbiome's functional potential. Probiotics are one of the most studied potential methods for reducing the microbiota-related consequences of antibiotics. However, the beneficial effects of probiotics are still under discussion. In addition, there are some concerns about the safety of probiotics, emphasizing the need for research of other therapeutic interventions. The aim of our study was to evaluate the influence of butyric acid+inulin supplements on gut microbiota changes (the gut microbiota composition, abundance of metabolic pathways, and gut resistome) caused by H. pylori eradication therapy.

MATERIALS AND METHODS

Twenty two H. pylori-positive patients, aged 19 to 64 years, were enrolled in the study and randomized into two treatment groups, as follows: (1) ECAB-14 (n = 11), with esomeprazole 20 mg, clarithromycin 500 mg, amoxicillin 1000 mg, and bismuthate tripotassium dicitrate 240 mg, twice daily, per os, for 14 days, and (2), ECAB-Z-14 (n = 11), with esomeprazole 20 mg, clarithromycin 500 mg, amoxicillin 1000 mg, and bismuthate tripotassium dicitrate 240 mg, twice daily, along with butyric acid+inulin (Zacofalk), two tablets daily, each containing 250 mg of butyric acid, and 250 mg of inulin, per os, for 14 days. Fecal samples were collected from each subject prior to eradication therapy (time point I), after the end of eradication therapy (time point II), and a month after the end of eradication therapy (time point III). The total DNA from the fecal samples was isolated for whole genome sequencing using the Illumina NextSeq 500 platform. Qualitative and quantitative changes in gut microbiota were assessed, including alpha and beta diversity, functional potential and antibiotic resistance gene profiling.

RESULTS

Gut microbiota alpha diversity significantly decreased compared with the baseline immediately after eradication therapy in both treatment groups (ECAB-14 and ECAB-Z-14). This diversity reached its baseline in the ECAB-Z-14 treatment group a month after the end of eradication therapy. However, in the ECAB-14 treatment arm, a reduction in the Shannon index was observed up to a month after the end of H. pylori eradication therapy. Fewer alterations in the gut microbiota functional potential were observed in the ECAB-Z-14 treatment group. The abundance of genes responsible for the metabolic pathway associated with butyrate production decreased only in the ECAB-14 treatment group. The prevalence of antibiotic-resistant genes in the gut microbiota increased significantly in both treatment groups by the end of treatment. However, more severe alterations were noted in the ECAB-14 treatment group.

CONCLUSIONS

H. pylori eradication therapy leads to taxonomic changes, a reduction in the alpha diversity index, and alterations in the functional potential of the gut microbiota and gut resistome. Taking butyric acid+inulin supplements during H. pylori eradication therapy could help maintain the gut microbiota in its initial state and facilitate its recovery after H. pylori eradication.

Prevalence of Histological Gastritis in a Community Population and Association with Epigastric Pain

BACKGROUND AND AIMS

Gastritis is a common histological diagnosis, although the prevalence is decreasing in developed populations, alongside decreasing prevalence of H. pylori infection. We sought to determine the prevalence of the etiology of gastritis in a Swedish population sample and to analyze any associations with symptoms, an area of clinical uncertainty.

METHODS

Longitudinal population-based study based in Östhammar, Sweden. A randomly sampled adult population completed a validated gastrointestinal symptom questionnaire (Abdominal Symptom Questionnaire, ASQ) in 2011 (N = 1175). Participants < 80 years of age and who were eligible were invited to undergo esophagogastroduodenoscopy (EGD) (N = 947); 402 accepted and 368 underwent EGD with antral and body biopsies (average 54.1 years, range 20-79 years; 47.8% male) with H. pylori serology.

RESULTS

Gastritis was found in 40.2% (148/368; 95% CI 35.2-45.2%). By rank, the most common histological subtype was reactive (68/148; 45.9%), then H. pylori (44/148; 29.7%), chronic non-H. pylori (29/148; 19.6%), and autoimmune (4/148; 2.7%). Gastritis was significantly associated with older age and H. pylori status (p < 0.01). Gastritis subjects were divided into three histological categories: chronic inactive inflammation, autoimmune gastritis, and active inflammation; there was no difference in the presence of upper gastrointestinal symptoms when categories were compared to cases with no pathological changes. Functional dyspepsia or gastroesophageal reflux were reported in 25.7% (38/148) of those with gastritis (any type or location) versus 34.1% (75/220) with no pathological changes (p = 0.32). Epigastric pain was more common in chronic H. pylori negative gastritis in the gastric body (OR = 3.22, 95% CI 1.08-9.62).

CONCLUSION

Gastritis is common in the population with a prevalence of 40% and is usually asymptomatic. Chronic body gastritis may be associated with epigastric pain, but independent validation is required to confirm these findings. Clinicians should not generally ascribe symptoms to histological gastritis.

Synthesis and biological evaluation against H. pylori of chitosan menthone Schiff base hybrid with different types of inorganic nanoparticles

The production of novel natural medicines for the treatment of Helicobacter pylori (H. pylori) has lately attracted a lot of interest. Some bacterial infections have traditionally been alleviated by terpenes. The present work intended to examine the impact of several chitosan menthone Schiff base nanocomposites on the treatment of H. pylori infection as well as on its anti-inflammatory capacity. Chitosan (Cs) was condensed with menthone with different molar ratios of Cs:menthone (1:0.5, 1:1, and 1:2) to produce chitosan Schiff bases namely; Cs-SB1, Cs-SB2, and Cs-SB3, respectively. Cs-SB3 Schiff base nanocomposites were prepared individually by adding 2%Ag, 2%Se, (1%Ag + 1%Se), and 2%Fe2O3 nanoparticles to produce compounds denoted as Cs-SB-Ag, Cs-SB-Se, Cs-SB-Ag/ Se, and Cs-SB-Fe, respectively. The anti-H. pylori activity of Cs-SB-Se was detected at a minimal inhibitory concentration MIC of 1.9 μg/mL making it the most biologically active compound in our study. Cs-SB-Se nanocomposite was tested for its cyclooxygenases (COX-1 and COX-2) inhibitory potential which demonstrated inhibitory efficacy towards COX enzymes with inhibition value against COX-1 (IC50 = 49.86 ± 1.784 μg/mL) and COX-2 (IC50 = 12.64 ± 0.463 μg/mL) which were less than the well-known Celecoxib (22.65 ± 0.081 and 0.789 ± 0.029 μg/mL) and Indomethacin (0.035 ± 0.001 and 0.08 ± 0.003 μg/mL) inhibitors. The selectivity index SI = 3.94 for tested nanocomposites indicated higher selectivity for COX-1. The cytotoxicity of the Cs-SB-Se nanocomposite was evaluated in Vero cells (CCL-81) and it showed that at a concentration of 62.5 μg/mL, cell viability was 85.43 %.

Sequential versus Standard Triple Therapy for First-Line Helicobacter pylori Eradication: An Update

BACKGROUND

non-bismuth sequential therapy (SEQ) was suggested as a first-line anti-Helicobacter pylori treatment alternative to standard triple therapy (STT).

METHODS

We conducted a systematic review with a meta-analysis of randomized controlled trials (RCTs) comparing the efficacy of 10-day SEQ vs. STT (of at least 7 days) using bibliographical searches up to July 2021, including treatment-naïve adult or children. The intention-to-treat (ITT) eradication rate and the risk difference (RD) were calculated.

RESULTS

Overall, 69 RCTs were evaluated, including 19,657 patients (9486 in SEQ; 10,171 in STT). Overall, SEQ was significantly more effective than STT (82% vs. 75%; RD 0.08; p < 0.001). The results were highly heterogeneous (I2 = 68%), and 38 studies did not demonstrate differences between therapies. Subgroup analyses suggested that patients with clarithromycin resistance only and all geographical areas but South America could benefit more from SEQ. Both therapies have evolved over the years, showing similar results when STT lasted 14 days; however, a tendency toward lower SEQ efficacy was noted from 2010 onwards.

CONCLUSIONS

Prior to 2010, SEQ was significantly more effective than STT, notably when 7-day STT was prescribed. A tendency toward lower differences between SEQ and STT has been noted, especially when using 10-day STT. None of the therapies achieved an optimal efficacy and therefore cannot be recommended as a valid first-line H. pylori treatment.

Exploring virulence factors of Helicobacter pylori isolated from gastric biopsy

BACKGROUND

Helicobacter pylori (H. pylori) colonizes human gastric mucosa and is classified as class one carcinogenic bacteria. In this regard, this study aimed to detect major virulence factors in H. pylori strains recovered from gastric biopsy in patients referred to Aras Clinique in Ardabil, northwest of Iran (2019-2021).

MATERIALS AND METHODS

In this descriptive-cross sectional study, 287 dyspeptic patients were included. For bacterial isolation, gastric biopsy specimens (n=287) were taken from gastric antrum, then aseptically were cultured on the selective medium and incubated at 37C in microaerophilic conditions for 3-5 days.

RESULTS

25.18% of all (n = 70) patients were found to be infected with H. pylori upon endoscopy. Of them, 9 patients (12.857%) and 2 patients (2.875%) had peptic ulcer disease and gastric cancer respectively. According to the different patterns of virulence factors, 57 virutypes were identified in which oipA-vacAs1-vacAm2 (3, 4.28% n =) and oipA-vacAs1-vacAs2-vacAm2 (3, 4.28% n =) were the most common patterns. The simultaneous presence of vacAS2, vacAm2 and hopQ2 genes was observed in both patients with gastric cancer. OipA (n = 562.5%), VacAs1 (n = 6.75%), VacAs2 (n = 6.75%), and VacAm2 (n = 787.5%) were found to be the most prevalent virulence factor.

CONCLUSION

According previous studies, it is confirmed that the cagPAI gene cluster and vacA gene alleles are strongly correlated with gastritis and gastrointestinal tract adenocarcinomas. Our study indicated that 50% of the indigenous strains of H. pylori harbor these oncogenic genes and they are hypervirulent.

Immune evasion by proteolytic shedding of natural killer group 2, member D ligands in Helicobacter pylori infection

Background

Helicobacter pylori (H. pylori) uses various strategies that attenuate mucosal immunity to ensure its persistence in the stomach. We recently found evidence that H. pylori might modulate the natural killer group 2, member 2 (NKG2D) system. The NKG2D receptor and its ligands are a major activation system of natural killer and cytotoxic T cells, which are important for mucosal immunity and tumor immunosurveillance. The NKG2D system allows recognition and elimination of infected and transformed cells, however viruses and cancers often subvert its activation. Here we aimed to identify a potential evasion of the NKG2D system in H. pylori infection.

Methods

We analyzed expression of NKG2D system genes in gastric tissues of H. pylori gastritis and gastric cancer patients, and performed cell-culture based infection experiments using H. pylori isogenic mutants and epithelial and NK cell lines.

Results

In biopsies of H. pylori gastritis patients, NKG2D receptor expression was reduced while NKG2D ligands accumulated in the lamina propria, suggesting NKG2D evasion. In vitro, H. pylori induced the transcription and proteolytic shedding of NKG2D ligands in stomach epithelial cells, and these effects were associated with specific H. pylori virulence factors. The H. pylori-driven release of soluble NKG2D ligands reduced the immunogenic visibility of infected cells and attenuated the cytotoxic activity of effector immune cells, specifically the anti-tumor activity of NK cells.

Conclusion

H. pylori manipulates the NKG2D system. This so far unrecognized strategy of immune evasion by H. pylori could potentially facilitate chronic bacterial persistence and might also promote stomach cancer development by allowing transformed cells to escape immune recognition and grow unimpeded to overt malignancy.

Autophagy-Related Gene ATG7 Polymorphism Could Potentially Serve as a Biomarker of the Progression of Atrophic Gastritis

Cytotoxin-associated gene A (CagA) is an oncoprotein that H. pylori injects into the host's gastric epithelial cells and that induces proinflammatory cytokines, such as interleukin (IL)-18 and IL-1β. As a result, it leads to atrophic gastritis (AG), a precancerous lesion of gastric cancer. On the other hand, host cells degrade CagA using autophagy systems. However, few studies exist about the single nucleotide polymorphisms (SNPs) in MAP1LC3A, MAP1LC3B, ATG4A, ATG4B, ATG4C, ATG7, and ATG13, which belong to the autophagy-related genes concerning AG. This study aimed to detect biomarkers associated with AG. Herein, H. pylori-positive subjects (n = 200) were divided into the AG (n = 94) and non-AG (n = 106) groups. Thirty tag SNPs were selected from the above seven candidate genes. The SNP frequency between the two groups was analyzed. The frequency of the C/T or T/T genotype at rs4683787 of ATG7 was significantly lower in the AG group than in the non-AG group (p = 0.034, odds ratio = 0.535). Based on multivariate analysis, the C/C genotype of rs4684787 and age were independently associated with gastric mucosal atrophy. This finding helps stratify the patients needing timely endoscopic screening or early eradication of H. pylori.

Epiberberine inhibits Helicobacter pylori and reduces host apoptosis and inflammatory damage by down-regulating urease expression

ETHNOPHARMACOLOGICAL RELEVANCE

With dramatically increasing antibiotic resistance in Helicobacter pylori (H. pylori), it is urgent to find alternative therapeutic agents. Rhizoma Coptidis is a traditional Chinese medicine for gastrointestinal diseases and shows excellent anti-H. pylori effect. Epiberberine (EPI), as one of the major alkaloids of Rhizoma Coptidis, has been reported to have urease-inhibiting activity, but its scavenging effect on H. pylori and the potential mechanism remain unclear.

AIM OF THE STUDY

To investigate the inhibitory effect of EPI on H. pylori and explore its multi-action on Helicobacter pylori urease (HPU).

MATERIALS AND METHODS

Using minimum inhibitory concentration (MIC) assay, minimum bactericidal concentration (MBC) assay, growth inhibition kinetics assay, bacterial resistance development, transmission electron microscope (TEM) assay, and animal experiments to investigate the inhibitory effect of EPI on H. pylori in vitro and in vivo. Using the Berthelot method, molecular docking and thermal displacement experiments to verify that EPI inhibits urease activity by interacting with HPU. Using transcriptome data, Real-Time PCR (RT-PCR) experiments to investigate the alterations in the expression of urease subunit ureB gene after EPI treatment. Using MTT cell viability assay, Hoechst 33342 staining method, JC-1 reagent detection method, western blot experiments, and Griess method to investigate the anti-apoptosis and anti-inflammation actions of EPI on gastric epithelial cells (GES-1) induced by HPU.

RESULTS

In vitro experiments proved that EPI has significant anti-H. pylori activity without drug resistance, induces H. pylori fragmentation and apoptosis. In vivo experiments showed that EPI has a certain clearance effect of H. pylori, and can reduce gastric inflammation caused by H. pylori infection. Transcriptome data, RT-PCR experiments, and other experiments demonstrate that EPI has a triple effect: (1) inhibiting the expression of HPU subunits ureB, (2) directly inhibiting urease activity by interacting with HPU, and (3) inhibiting HPU-induced apoptosis and inflammation in GES-1.

CONCLUSIONS

EPI is an excellent anti-H. pylori agent and reduces host apoptosis and inflammation by inhibiting the activity of urease and down-regulating the expression of ureB.

Future Nanotechnology-Based Strategies for Improved Management of Helicobacter pylori Infection

Helicobacter pylori (H. pylori) is a recalcitrant pathogen, which can cause gastric disorders. During the past decades, polypharmacy-based regimens, such as triple and quadruple therapies have been widely used against H. pylori. However, polyantibiotic therapies can disturb the host gastric/gut microbiota and lead to antibiotic resistance. Thus, simpler but more effective approaches should be developed. Here, some recent advances in nanostructured drug delivery systems to treat H. pylori infection are summarized. Also, for the first time, a drug release paradigm is proposed to prevent H. pylori antibiotic resistance along with an IVIVC model in order to connect the drug release profile with a reduction in bacterial colony counts. Then, local delivery systems including mucoadhesive, mucopenetrating, and cytoadhesive nanobiomaterials are discussed in the battle against H. pylori infection. Afterward, engineered delivery platforms including polymer-coated nanoemulsions and polymer-coated nanoliposomes are poposed. These bioinspired platforms can contain an antimicrobial agent enclosed within smart multifunctional nanoformulations. These bioplatforms can prevent the development of antibiotic resistance, as well as specifically killing H. pylori with no or only slight negative effects on the host gastrointestinal microbiota. Finally, the essential checkpoints that should be passed to confirm the potential effectiveness of anti-H. pylori nanosystems are discussed.

Helicobacter pylori-Induced Gastroduodenal Stricture in a Child

Helicobacter pylori is a known cause of peptic ulcers, but it has not been reported to cause strictures in children. We present the case of a previously healthy 12-year-old boy with sudden onset of abdominal pain and vomiting, positive stool H. pylori antigen testing, and esophagogastroduodenoscopy revealing a gastroduodenal stricture causing gastric outlet obstruction. Because of medically refractory disease, he ultimately required laparoscopic truncal vagotomy with open pyloroplasty. This is an unusually severe presentation and may warrant H. pylori being on the differential of pediatric gastrointestinal strictures as well as further discussion on other long-term implications.

Association between MUC1 rs4072037 polymorphism and Helicobacter pylori in patients with gastric cancer

Background

The MUC1 gene encodes glycoproteins attached to cell membrane that play a protective role in gastric cancer and protect epithelial surfaces against external factors such as Helicobacter pylori. H. pylori infection can induce a cascade of innate and acquired immune responses in gastric mucosa. Relationship between rs4072037G>A polymorphism of MUC1 gene and increased susceptibility to H. pylori infection aimed to investigate in patients with gastric cancer in Mazandaran, northern Iran.

Methods

A case-control study was conducted on 99 patients with gastric cancer (H. pylori positive and negative) and 98 controls (H. pylori positive and negative) without gastric cancer (confirmed by pathological biopsy samples obtained during endoscopy). H. pylori infection was diagnosed by histological examination using Giemsa staining. Genomic DNA extracted from peripheral blood was analyzed by PCR-RFLP technique.

Results

Analysis of all genetic models showed no significant relationship between rs4072037G>A polymorphism and risk of gastric cancer (GC). The relationship between H. pylori infection and rs4072037G>A polymorphism showed an increased susceptibility to gastric cancer in both positive and negative H. pylori groups (including case and control groups). The genetic model of GA/GG and H. pylori- positive versus GA/GG and H. pylori-negative showed a significantly increased susceptibility to gastric cancer (OR=0.251, CI: 0.128-0.493, P=0.000).

Conclusion

These findings indicate that rs4072037G>A polymorphism may interact with H. pylori infection to increase the risk of GC.

Diagnosis of ''Helicobacter pylori infection of the gastric biopsy'' by rapid urease test, histopathology and Raman spectroscopy

This study aim to investigate the diagnostic potential of Raman spectroscopy in comparison with rapid urease test and histopathology in diagnosis of H. pylori infection. A comparative study was conducted at Pathology Laboratory and a total of 94 samples were collected from patients based on Rome IV criteria. Sensitivity, specificity and accuracy of histopathology, rapid urease test and for Raman spectroscopy were investigated. Rapid urease test showed 23 false negative results of H. pylori as compared to Raman spectroscopy and histopathology. We concluded that Raman spectroscopy showed sensitivity (94.5%), accuracy (94.0%) and specificity of (87.5%) in the diagnosis of H. pylori infection. However rapid urease test showed specificity of 92.5% while low sensitivity 75%, and 78% accuracy as compared to Raman spectroscopy and histopathology . This study illustrates the applicability of Raman spectroscopy as a potent innovative detection tool for the molecular detection of H. pylori infection in gastritis.

Co-administration of amoxicillin-loaded chitosan nanoparticles and inulin: A novel strategy for mitigating antibiotic resistance and preserving microbiota balance in Helicobacter pylori treatment

Helicobacter pylori (H. pylori) is a causative agent of various gastrointestinal diseases and eradication mainly relies on antibiotic treatment, with (AMX) being a key component. However, rising antibiotic resistance in H. pylori necessitates the use of antibiotics combination therapy, often disrupting gut microbiota equilibrium leading to further health complications. This study investigates a novel strategy utilizing AMX-loaded chitosan nanoparticles (AMX-CS NPs), co-administered with prebiotic inulin to counteract H. pylori infection while preserving microbiota health. Following microbroth dilution method, AMX displayed efficacy against H. pylori, with a MIC50 of 48.34 ± 3.3 ng/mL, albeit with a detrimental impact on Lactobacillus casei (L. casei). The co-administration of inulin (500 μg/mL) with AMX restored L. casei viability while retaining the lethal effect on H. pylori. Encapsulation of AMX in CS-NPs via ionic gelation method, resulted in particles of 157.8 ± 3.85 nm in size and an entrapment efficiency (EE) of 86.44 ± 2.19 %. Moreover, AMX-CS NPs showed a sustained drug release pattern over 72 h with no detectable toxicity on human dermal fibroblasts cell lines. Encapsulation of AMX into CS NPs also reduced its MIC50 against H. pylori, while its co-administration with inulin maintained L. casei viability. Interestingly, treatment with AMX-CS NPs also reduced the expression of the efflux pump gene hefA in H. pylori. This dual treatment strategy offers a promising approach for more selective antimicrobial treatment, minimizing disruption to healthy microbial communities while effectively addressing pathogenic threats.

The Interplay between Helicobacter pylori and Gut Microbiota in Non-Gastrointestinal Disorders: A Special Focus on Atherosclerosis

The discovery of Helicobacter pylori (H. pylori) in the early 1980s by Nobel Prize winners in medicine Robin Warren and Barry Marshall led to a revolution in physiopathology and consequently in the treatment of peptic ulcer disease. Subsequently, H. pylori has also been linked to non-gastrointestinal diseases, such as autoimmune thrombocytopenia, acne rosacea, and Raynaud's syndrome. In addition, several studies have shown an association with cardiovascular disease and atherosclerosis. Our narrative review aims to investigate the connection between H. pylori infection, gut microbiota, and extra-gastric diseases, with a particular emphasis on atherosclerosis. We conducted an extensive search on PubMed, Google Scholar, and Scopus, using the keywords "H. pylori", "dysbiosis", "microbiota", "atherosclerosis", "cardiovascular disease" in the last ten years. Atherosclerosis is a complex condition in which the arteries thicken or harden due to plaque deposits in the inner lining of an artery and is associated with several cardiovascular diseases. Recent research has highlighted the role of the microbiota in the pathogenesis of this group of diseases. H. pylori is able to both directly influence the onset of atherosclerosis and negatively modulate the microbiota. H. pylori is an important factor in promoting atherosclerosis. Progress is being made in understanding the underlying mechanisms, which could open the way to interesting new therapeutic perspectives.

A comparative systematic review and meta-analysis on the diagnostic accuracy of non-invasive tests for Helicobacter pylori detection in elderly patients

Background

Helicobacter pylori (H. pylori) infection, a type I carcinogen, affects approximately 50% of the global population, correlating with various gastric pathologies. Notably, diagnostic sensitivities of non-invasive methods, such as the stool antigen test (HpSA), Serology, and Urea Breath Test (UBT), have been suggested to be less effective in older age groups. This study systematically reviews and meta-analyzes the diagnostic accuracy of these tests within the elderly population.

Methods

A comprehensive literature search was performed across multiple databases, including PubMed, Medline, and Web of Science, up to July 2023. Data were pooled and analyzed using random-effects models. Sensitivity, specificity, and Diagnostic Odds Ratios (DOR) were computed for the tests. Heterogeneity and risk of bias were assessed.

Results

Eight studies involving diverse geographic locations and totaling between 46 and 1,441 participants per study were included. The pooled sensitivity and specificity for HpSA were 72.5 and 94.7%, for Serology 83.7 and 73.3%, and for UBT 96.4 and 88.3%, respectively. DOR for UBT, HpSA, and Serology were 94.5, 47.9, and 14.2, respectively. High levels of heterogeneity were observed across the studies.

Conclusion

UBT and HpSA proved effective for diagnosing H. pylori in those over 60, while serology showed lower specificity. Despite methodological variations in available studies, these non-invasive tests offer reliable alternatives, especially for older patients who recently undergone endoscopy or without an indication for it, warranting consideration by healthcare practitioners.

Outcome and patterns of relapse in primary gastric diffuse large B cell lymphoma treated with RCHOP

OBJECTIVES

Patterns and predictors of relapse in primary gastric diffuse large B cell lymphoma (DLBCL) were variably reported. Our study aims to evaluate the patterns and predictors of relapse in early-stage gastric DLBCL treated with Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, and Prednisolone (RCHOP).

METHODS

From 2005 to 2019, the medical records of 72 patients with stage I or stage II gastric DLBCL treated with six cycles of RCHOP without radiotherapy were reviewed. Different variables were correlated with progression free survival (PFS), overall survival (OS), and local relapse free survival (LRFS).

RESULTS

64 (88.1%) patients achieved a complete response (CR), while 8 (11.9%) had refractory disease. After CR, 9 (14%) patients relapsed; 7 (78%) relapses were loco-regional. Abnormal LDH (p = 0.028), H. pylori negative (p = 0.032) and, stage adjusted international prognostic index (sa-IPI) > 1 (p = 0.013) correlated with loco-regional failure. The 5-year PFS, OS, and LRFS were 74.8%, 75.3%, and 87.5%, respectively, after a median follow-up of 58 (range: 6-185) months. The median time to progression or relapse was 9 months (range: 5-54 months). In multivariate analysis, a sa-IPI >1 (HR: 3.56, CI: 1.35-8.8, p = 0.01) was associated with PFS while low albumin (HR: 8.85, CI: 1.09-71.4, p = 0.041) was associated with worse OS. None of the variables were associated with LRFS.

CONCLUSION

Treatment of primary gastric DLBCL with RCHOP results in a high CR rate. The majority of treatment failures were loco-regional. Sa-IPI and H. pylori status may be used to identify patients who may benefit from combined modality treatment.

In silico study revealed the inhibitory activity of selected phytomolecules of C. rotundus against VacA implicated in gastric ulcer

Gastric ulcer is associated with weakening of the mucous coating of the stomach and damages to the intestinal lining. It is caused by H. pylori assisted by enzymes including VacA, which necessitates the need for inhibitors of VacA. Bioactive compounds from Cyperus rotundus have been documented to have anti-inflammatory activities. However, the mechanism of action of the phytochemicals is not characterized. This research aimed to assess, in silico, the potential of selected bioactive compounds against VacA based on the binding to its active sites. VacA and bioactive compounds structures were obtained from protein database and PubChem webserver, respectively. All compounds, including 2 controls, omeprazole and cimetidine were docked against the protein using AutoDock Vina and screened based on the binding energy. The selected complexes were subjected to pharmacokinetics and toxicity screening. Finally, molecular dynamics simulation and MMPBSA were carried out on two best compounds. 17 compounds interacted with the active site of VacA with higher binding affinities, with 7 of them - aureusidine, catechin, chlorogenic acid, isorhamnetin, isovitexin, oreintin, and vitexin having the best behaviours based on ADMET and druglikeness screening. Molecular dynamics and MMPBSA experiments of two of the hits corroborated good stability and binding energy for Ellagic Acid and Scirpusin B (ΔG = -14.38 and -13.20 kcal mol-1, respectively). These phytochemicals showed good pharmacokinetic profiles with respect to the control drugs. This study revealed that the identified compounds of C. rotundus may serve as VacA inhibitors and may be potent candidates for novel drug formulations in gastric ulcer treatment.Communicated by Ramaswamy H. Sarma.

Exploration of gastric carcinogenesis from the relationship between bile acids and intestinal metaplasia and intragastric microorganisms (H. pylori and non-H. pylori)

Gastric cancer (GC) is a prevalent form of cancer, with Helicobacter pylori (H. pylori) infection being the most common risk factor. Recent studies have highlighted the role of long-term irritation of the gastric mucosa caused by bile reflux in the development of cancer. Bile acids (BAs), which are a significant component in bile reflux, have the potential to promote gastric carcinogenesis through various mechanisms. These mechanisms include the induction of intestinal metaplasia (IM), inhibition of H. pylori activity, modification of H. pylori colonization, and alteration of the abundance and composition of microorganisms in the stomach. Defining the mechanism of bile acid-induced gastric carcinogenesis could potentially be an effective approach to prevent GC. Hence, this paper aims to review the mechanism of bile acid-induced IM, the association between BAs and H. pylori infection as well as microorganisms in the stomach, and the correlation between BAs and gastric carcinogenesis. The ultimate goal is to elucidate the role of BAs in the development of GC.

Methylation Status of CDH1 Gene in Gastric Biopsy Specimens and Its Association with H. Pylori Infection

BACKGROUND

Helicobacter pylori (H. pylori) have been accepted as having an etiologic role in gastro-duodenal diseases as chronic gastritis, peptic ulcer, and gastric carcinoma. Methylation of CGI has been correlated with the tumorigenic process since it can inactivate tumor suppressor genes. CDH1 is a tumor suppressor gene that encodes the E-cadherin protein, which is preserving cell-cell connections. Early stages of gastric carcinogenesis may be affected by the promoter methylation-mediated inactivation of this gene.

OBJECTIVE

This study aimed to investigate the methylation status of CDH1 using Methylation-Specific PCR (MSP) technique in clinical suspected patients with H. pylori infection who undergoing upper gastrointestinal endoscopy and correlated it with H. pylori detection by glmM PCR test.

METHODS

Fifty gastric mucosal biopsies were selected from one hundred and five samples included in this study. The detection of H. pylori was performed with the PCR primers specific to glmM gene. Bisulfite modification was done and the methylation status of the CDH1 gene was detected using MSP reaction.

RESULTS

H. pylori was detected in 36% (18/50) of study population using glmM gene PCR test, 89% (16/18) of H. pylori positive cases were CDH1 methylated  positive (chi-square, p-value=0.002). CDH1 methylation can be present in cancerous and noncancerous gastric mucosa, where 60% (18/30) of CDH1 methylation positive gastric mucosa showed gastritis as an endoscopy finding and gastric cancer in 6% (2/30). There was a significant correlation between and CDH1 methylation positive results and age group (P-value = 0.02). There was no significant correlation between CDH1 methylation positive results and participants gender (p-value=0.431) and clinical symptoms (all P-value > 0.05).

CONCLUSION

This work suggested strong significance association between H. pylori infection and CDH1 methylation.