Helicobacter pylori Infection and Gastric Dysbiosis: Can Probiotics Administration Be Useful to Treat This Condition?

Crosstalk between COVID-19 and the gut-brain axis: a gut feeling

The microbes in the gut are crucial for maintaining the body's immune system and overall gut health. However, it is not fully understood how an unstable gut environment can lead to more severe cases of SARS-CoV-2 infection. The gut microbiota also plays a role in the gut-brain axis and interacts with the central nervous system through metabolic and neuroendocrine pathways. The interaction between the microbiota and the host's body involves hormonal, immune, and neural pathways, and any disruption in the balance of gut bacteria can lead to dysbiosis, which contributes to pathogen growth. In this context, we discuss how dysbiosis could contribute to comorbidities that increase susceptibility to SARS-CoV-2. Probiotics and fecal microbiota transplantation have successfully treated infectious and non-infectious inflammatory-related diseases, the most common comorbidities. These treatments could be adjuvant therapies for COVID-19 infection by restoring gut homeostasis and balancing the gut microbiota.

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.

Helicobacter pylori infection in humans and phytotherapy, probiotics, and emerging therapeutic interventions: a review

The global prevalence of Helicobacter pylori (H. pylori) infection remains high, indicating a persistent presence of this pathogenic bacterium capable of infecting humans. This review summarizes the population demographics, transmission routes, as well as conventional and novel therapeutic approaches for H. pylori infection. The prevalence of H. pylori infection exceeds 30% in numerous countries worldwide and can be transmitted through interpersonal and zoonotic routes. Cytotoxin-related gene A (CagA) and vacuolar cytotoxin A (VacA) are the main virulence factors of H. pylori, contributing to its steep global infection rate. Preventative measures should be taken from people's living habits and dietary factors to reduce H. pylori infection. Phytotherapy, probiotics therapies and some emerging therapies have emerged as alternative treatments for H. pylori infection, addressing the issue of elevated antibiotic resistance rates. Plant extracts primarily target urease activity and adhesion activity to treat H. pylori, while probiotics prevent H. pylori infection through both immune and non-immune pathways. In the future, the primary research focus will be on combining multiple treatment methods to effectively eradicate H. pylori infection.

Gastric microbiota: an emerging player in gastric cancer

Gastric cancer (GC) is a common cancer worldwide with a high mortality rate. Many microbial factors influence GC, of which the most widely accepted one is Helicobacter pylori (H. pylori) infection. H. pylori causes inflammation, immune reactions and activation of multiple signaling pathways, leading to acid deficiency, epithelial atrophy, dysplasia and ultimately GC. It has been proved that complex microbial populations exist in the human stomach. H. pylori can affect the abundance and diversity of other bacteria. The interactions among gastric microbiota are collectively implicated in the onset of GC. Certain intervention strategies may regulate gastric homeostasis and mitigate gastric disorders. Probiotics, dietary fiber, and microbiota transplantation can potentially restore healthy microbiota. In this review, we elucidate the specific role of the gastric microbiota in GC and hope these data can facilitate the development of effective prevention and therapeutic approaches for GC.

Current understanding of antibiotic-associated dysbiosis and approaches for its management

Increased exposure to antibiotics during early childhood increases the risk of antibiotic-associated dysbiosis, which is associated with reduced diversity of gut microbial species and abundance of certain taxa, disruption of host immunity, and the emergence of antibiotic-resistant microbes. The disruption of gut microbiota and host immunity in early life is linked to the development of immune-related and metabolic disorders later in life. Antibiotic administration in populations predisposed to gut microbiota dysbiosis, such as newborns, obese children, and children with allergic rhinitis and recurrent infections; changes microbial composition and diversity; exacerbating dysbiosis and resulting in negative health outcomes. Antibiotic-associated diarrhea (AAD), Clostridiodes difficile-associated diarrhea (CDAD), and Helicobacter pylori infection are all short-term consequences of antibiotic treatment that persist from a few weeks to months. Changes in gut microbiota, which persist even 2 years after antibiotic exposure, and the development of obesity, allergies, and asthma are among the long-term consequences. Probiotic bacteria and dietary supplements can potentially prevent or reverse antibiotic-associated gut microbiota dysbiosis. Probiotics have been demonstrated in clinical studies to help prevent AAD and, to a lesser extent, CDAD, as well as to improve H pylori eradication rates. In the Indian setting, probiotics (Saccharomyces boulardii and Bacillus clausii) have been shown to reduce the duration and frequency of acute diarrhea in children. Antibiotics may exaggerate the consequences of gut microbiota dysbiosis in vulnerable populations already affected by the condition. Therefore, prudent use of antibiotics among neonates and young children is critical to prevent the detrimental effects on gut health.

Lactobacillus rhamnosus GG supplementation on eradication rate and dyspepsia in Helicobacter pylori infection treated with three-in-one bismuth quadruple therapy

Introduction

Helicobacter pylori (Hp)-related dyspepsia has been related to gastroduodenal dysbiosis. The role of probiotic supplementation in the clinical management of Hp infection has been the object of several studies in terms of improvement of efficacy and tolerability of eradication treatments but data on their effects on the outcomes of post-eradication dyspepsia are lacking. The aim of the present study was to evaluate the influence of Lactobacillus rhamnosus GG (LGG) supplementation on bismuth quadruple therapy (BQT) in the clinical management of Hp-related infection both in terms of efficacy and tolerability and persistence of post-treatment dyspepsia.

Methods

A total of 164 (121 women) Hp-positive adult patients were enrolled in this pilot study and assigned to two different treatment regimens: group A received BQT for 10 days (three capsules qid, IPP bid) and group B received BQT for 10 days in combination with 6 × 10⁹CFU LGG (ATCC53103) taken for 24 days (7 days before, 10 days during, and 7 days after therapy). Eradication was assessed after 45 days using the ¹³C-urea breath test (¹³C-UBT). Dyspepsia, distinguished into postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS), was assessed at the time of enrollment and 6 months after eradication.

Results

Approximately 98 patients were enrolled in group A and 66 patients in group B. At the enrollment, dyspepsia was present in 76.5% of group A and 86.5% of group B. No significant differences were observed in eradication rate between the 2 groups, both in intention-to-treat (ITT) analysis (82.3 vs. 75.0%) and per-protocol (PP) analysis (95 vs. 96%), and in the presence of side effects during the treatment (70.6 vs. 65.4%). At 6 months after eradication of Hp infection, the persistence of dyspepsia was statistically higher in patients of group A than in group B (38.8 vs. 16.1%; p = 0.032). The positive influence of LGG supplementation in improving post-eradication dyspepsia resulted in statistically more effectiveness in PDS dyspepsia, whose remission was 41.7% in group A and 84% in group B patients (p = 0.011).

Conclusion

In conclusion, LGG supplementation during Hp eradication therapy, even if not affecting eradication rates and therapy-related side effects, significantly impacts the remission of dyspepsia.

Therapeutic effects of probiotics combined with quadruple anti-Helicobacter pylori therapy in coronary artery disease patients with long-term antiplatelet-induced upper gastrointestinal mucosal damage

BACKGROUND

Long-term antiplatelet therapy may cause damage to the upper gastrointestinal mucosa of patients with coronary heart disease. Probiotics can not only improve intestinal micro-ecology, but also effectively antagonize Helicobacter pylori (H. pylori). In this study, we explored whether probiotics can improve the upper gastrointestinal mucosa damage caused by long-term antiplatelet therapy in patients with coronary heart disease.

AIM

To investigate the effect of probiotics combined with quadruple anti-H. pylori therapy in coronary artery disease patients with long-term antiplatelet-induced upper gastrointestinal mucosal damage.

METHODS

A total of 220 patients with coronary artery disease on long-term antiplatelet therapy at our hospital from January 2019 to June 2021 were selected, and all of them had upper gastrointestinal mucosal damage and were positive for H. pylori. The patients were randomly divided into either a control group or an observation group (110 cases each). The control group was treated with quadruple anti-H. pylori therapy, and the observation group was treated with probiotics combined with quadruple anti-H. pylori therapy. The clinical efficacy, eradication rate of H. pylori, and changes of gastrointestinal mucosal pathology score, gastrointestinal function indexes [pepsinogen Ⅱ(PG Ⅱ), pepsinogen Ⅰ (PG Ⅰ), and gastrin-17 (G-17)], inflammatory factors [tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-8] were compared in the two groups, and endpoint events were recorded.

RESULTS

The total clinical treatment efficiency of the observation group was 88.18%, which was significantly higher than that of the control group (78.18%; P < 0.05). The eradication rate of H. pylori at 6 mo after drug discontinuation was significantly higher in the observation group than in the control group (P < 0.05). Inflammation, atrophy, intestinal epithelial chemosis, and heterotypic hyperplasia scores were significantly lower in the observation group than in the control group after treatment (P < 0.05). Serum PG Ⅰ, PG Ⅱ, and G-17 levels were significantly lower in the observation group than in the control group (P < 0.05). Serum TNF-α, IL-6, and IL-8 levels were also significantly lower in the observation group than in the control group after treatment (P < 0.05).

CONCLUSION

The addition of probiotics to the long-term antiplatelet-induced upper gastrointestinal mucosal damage treatment in patients with coronary artery disease is beneficial for clinical outcomes, effectively improving H. pylori eradication rates, reducing inflammatory responses, and decreasing the risk of carcinogenesis.

Basic Traditional Chinese Medicinal Compound for Adjuvant Treatment of Helicobacter pylori-Related Gastritis: Implication for Anti-H. pylori-Related Gastritis Drug Discovery

This study was aimed at evaluating the efficacy of traditional Chinese medicine (TCM) in the adjuvant treatment of Helicobacter pylori-associated gastritis (HPAG) and exploring the molecular mechanism underlying the action of the basic TCM compounds against HPAG. Eight representative Chinese and British databases were combed for pertinent literature. In light of the basic principle of evidence-based medicine, this work rigorously stuck to the inclusion and exclusion of criteria so as to plump for qualified articles. Also, the data mining method was adopted to help determine the basic TCM compound for HPAG treatment. Furthermore, a network pharmacology-based strategy was used to uncover the underlying mechanisms of the basic TCM compound against HPAG. Ultimately, molecular docking was used for preliminary verification. TCM combined with triple or quadruple therapy against HPAG possessed more advantages in improving the total effective rate and H. pylori eradication rate than triple or quadruple therapy alone. The basic TCM plant materials against HPAG consisted of Citrus reticulata Blanco, Glycyrrhiza uralensis Fisch, Pinellia ternata (Thunb.) Breit, Coptis chinensis Franch, and Poria cocos (Schw.) Wolf. Quercetin, kaempferol, naringenin, baicalein, nobiletin, and hederagenin were determined as the key active ingredients of the basic TCM preparation against HPAG. Moreover, these ingredients played a therapeutic role by acting on AKT1, TP53, interleukin (IL)-6, VEGFA, CASP3, MAPK3, JUN, TNF, and MAPK8 via Pathways in cancer, PI3K-Akt signaling pathway, TNF signaling pathway, and MAPK signaling pathway. The results of molecular docking indicated that the key ingredients could bind stably with the core targets. The efficacy of the TCM in the adjuvant treatment of HPAG is worthy of affirmation. Compatible use of the key ingredients of the basic TCM compound is a novel idea of drug research with profound clinical significance and research value in the development of anti- H. pylori drugs.

[Characteristics of gastric microbiota in children with Helicobacter pylori infection family history]

OBJECTIVE

To explore the characteristics of gastric microbiota in children with and without (Helicobacter pylori, H. pylori) infection who had family history of H. pylori infection.

METHODS

Mucosal biopsy samples of the gastric corpus and gastric antrum were collected during the gastroscope. And the gastric mucosa flora's information of the two groups of children were obtained after sample DNA extraction, PCR amplification of the 16S ribosomal DNA (rDNA) V3-V4 region, high-throughput sequencing and data processing. All the samples with family history of H. pylori infection were divided into two groups, the H. pylori infection group (n=18) and the H. pylori non-infection group (n=24). Then the α-, β-diversity and bacteria abundance of the gastric microbiota were compared between the H. pylori infection and non-infection groups at different taxonomic levels. The differential microbiota was found out by LEfSe analysis, and then the function of microbiota predicted using phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) method.

RESULTS

There was statistically significant difference in α-diversity (P < 0.05) between the two groups, indicating that the H. pylori non-infection group had higher microbial richness than the H. pylori infection group. Moreover, the β-diversity was significantly different as well (P < 0.05), which meant that the microbiota composition of the two groups was different. At the phyla level, Proteobacteria, Firmicutes, Bacteroides, Actinobacteria, and Fusobacteria were dominant in the two groups. At the genus level, Bacteroides, Prevotella, Streptococcus, and Neisseria, etc. were dominant in the H. pylori non-infected group. Meanwhile, Helicobacter and Haemophilus etc. were dominant in the H. pylori infected group. LEfSe analysis showed that the relative abundance of Bacteroides etc. at the genus level in the H. pylori non-infected group was significantly higher than that in the H. pylori infected group. Functional prediction showed that Bacteroides were positively correlated with amino acid and vitamin metabolism, mitogen-activated protein kinase (MAPK), mammalian target of rapamycin (mTOR) signaling pathway and ansamycin synthesis pathway.

CONCLUSION

The gastric microbiota between H. pylori positive and H. pylori negative in children with family history of H. pylori infection is significant different. Some gastric microbiota, such as Bacteroides, may have a potential relationship with H. pylori infection in children.

Paradigm shift in the pathogenesis and treatment of oral cancer and other cancers focused on the oralome and antimicrobial-based therapeutics

The oral microbiome is a community of microorganisms, comprised of bacteria, fungi, viruses, archaea, and protozoa, that form a complex ecosystem within the oral cavity. Although minor perturbations in the environment are frequent and compensable, major shifts in the oral microbiome can promote an unbalanced state, known as dysbiosis. Dysbiosis can promote oral diseases, including periodontitis. In addition, oral dysbiosis has been associated with other systemic diseases, including cancer. The objective of this review is to evaluate the epidemiologic evidence linking periodontitis to oral, gastrointestinal, lung, breast, prostate, and uterine cancers, as well as describe new evidence and insights into the role of oral dysbiosis in the etiology and pathogenesis of the cancer types discussed. Finally, we discuss how antimicrobials, antimicrobial peptides, and probiotics may be promising tools to prevent and treat these cancers, targeting both the microbes and associated carcinogenesis processes. These findings represent a novel paradigm in the pathogenesis and treatment of cancer focused on the oral microbiome and antimicrobial‐based therapies.

Impact of Environmental and Pharmacologic Changes on the Upper Gastrointestinal Microbiome

Diseases of the upper gastrointestinal tract have become more prevalent over time. Mechanisms of disease formation are still only partially understood. Recent literature has shown that the surrounding microbiome affects the propensity for disease formation in various parts of the upper gastrointestinal tract. A review was performed of any literature to our best knowledge concerning the effects of pharmacologic agents, environmental changes, and surgical intervention on the microbiome of the upper gastrointestinal tract. Searches of the literature were performed using specific keywords related to drugs, surgical procedures, and environmental factors. Many prescription and nonprescription drugs that are commonly used have varying effects on the upper gastrointestinal tract. Proton pump inhibitors may affect the relative prevalence of some organisms in the lower esophagus and have less effect in the proximal esophagus. Changes in the esophageal microbiome correlate with some esophageal diseases. Drugs that induce weight loss have also been shown to affect the microbiomes of the esophagus and stomach. Common surgical procedures are associated with shifts in the microbial community in the gastrointestinal tract. Environmental factors have been shown to affect the microbiome in the upper gastrointestinal tract, as geographic differences correlate with alterations in the microbiome of the gastrointestinal tract. Understanding the association of environmental and pharmacologic changes on the microbiome of the upper gastrointestinal tract will facilitate treatment plans to reduce morbidity from disease.

Outer Membrane Vesicles of Helicobacter pylori 7.13 as Adjuvants Promote Protective Efficacy Against Helicobacter pylori Infection

Helicobacter pylori(H. pylori), a gram-negative bacterium in the human stomach with global prevalence, is relevant to chronic gastrointestinal diseases. Due to its increasing drug resistance and the low protective efficacy of some anti-H. pylori vaccines, it is necessary to find a suitable adjuvant to improve antigen efficiency. In our previous study, we determined that outer membrane vesicles (OMVs), a multicomponent secretion generated by gram-negative bacteria, of H. pylori were safe and could induce long-term and robust immune responses against H. pylori in mice. In this study, we employed two common vaccines, outer membrane proteins (OMPs) and whole cell vaccine (WCV) to assess the adjuvanticity of OMVs in mice. A standard adjuvant, cholera toxin (CT), was used as a control. Purified H. pylori OMVs used as adjuvants generated lasting anti-H. pylori resistance for 12 weeks. Additionally, both systematic and gastric mucosal immunity, as well as humoral immunity, of mice immunized with vaccine and OMVs combinations were significantly enhanced. Moreover, OMVs efficiently promoted Th1 immune response, but the response was skewed toward Th2 and Th17 immunity when compared with that induced by the CT adjuvant. Most importantly, OMVs as adjuvants enhanced the eradication of H. pylori. Thus, OMVs have potential applications as adjuvants in the development of a new generation of vaccines to treat H. pylori infection.

Clinical efficacy of the modified Helicobacter pylori eradication therapy for Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma: a meta analysis

Background

Helicobacter pylori (HP) has been considered to be one of the primary causes of gastric mucosa-associated lymphoid tissue (MALT) lymphoma since 1993. Low-grade gastric MALT lymphoma with HP is widely treated with HP eradication therapy, according to each specific clinical situation. However, several studies and guidelines indicate that the modified HP eradication therapy is also valid for HP-negative gastric MALT lymphoma. The aim of this study was to perform a meta-analysis of the clinical efficacy of the modified HP eradication therapy for gastric MALT lymphoma without HP.

Methods

We searched studies that reported the response rate of the modified HP eradication therapy regimen for gastric MALT lymphoma without HP by using PubMed, Medline, and Ebsco from January 1971 until February 2019. All statistical analyses were carried out using R 3.5.3 (Mathsoft Company, Cambridge, MA, USA). The pooled response rate was expressed as a decimal. The heterogeneity test was performed using the I-squared (I²) statistic.

Results

A total of 14 studies were selected with a total of 148 patients with HP-negative gastric MALT lymphoma. The overall pooled response rate was 0.38 (95% confidence interval [CI]: 0.29–0.47). The combined estimate is I² = 57% (P < 0.01). The study subjects were categorized by factors (area of patients). The pooled response rate of the sub-groups (Korea, Japan, China, and Western countries) was 0.63 (95% CI: 0.50–0.76), 0.16 (95% CI: 0.05–0.30), 0.38 (95% CI: 0.20–0.55), and 0.57 (95% CI: 0.08–1.00). The response rate showed that the modified HP eradication therapy was effective for patients with HP-negative gastric MALT lymphoma, especially in Korea and Western countries.

Conclusion

Therefore, the modified HP eradication therapy can be considered an optional therapy for patients with low-grade HP-negative gastric MALT lymphoma. However, several limitations were revealed in the meta-analysis. Further systematic reviews and research are required.

Mucosa microbiome of gastric lesions: Fungi and bacteria interactions

Many components of the gastric non-Helicobacter pylori microbiota have been identified recently thanks to advances in DNA sequencing techniques. Several lines of evidence support the hypothesis that the gastric microbiome is essential for gastric disorders such as gastric cancer. Microbial interactions impact the pathophysiology of various gastric disorders. This chapter provides an overview of recent findings regarding general gastric microbial community profiling, microbial interactions in the stomach, and microbial characteristics in various gastric disorders.

Selected commensal bacteria change profiles of Helicobacter pylori-induced T cells via dendritic cell modulation

BACKGROUND

The mechanisms of downregulation of protective immunity against Helicobacter pylori (Hp) infection strongly depend on dendritic cell (DC)-induced T-lymphocyte differentiation pattern. Lactic acid bacteria (LAB) strains can modulate Hp-induced immunoresponse by changes in DC activation profiles. Here, we want to find out if the LAB-pulsed DCs will change Hp-induced T-cell responsiveness patterns.

MATERIALS AND METHODS

The naive peripheral CD4⁺ T cells were co-cultured with Hp CagA + pulsed monocyte-derived DCs (DC/CD4⁺ T cell) in the presence/absence of the feces-derived probiotics: antagonistic or non-antagonistic to Hp (Lactobacillus rhamnosus 900, Lr, Lactobacillus paracasei 915, Lp, respectively), as assessed by the agar slab method. The regulatory T-cell (Treg) population was assessed by flow cytometry, and IFN-γ, IL-12p70, IL-10, and IL-17A levels were evaluated by ELISA method.

RESULTS

The Hp-pulsed DC/CD4⁺ T-cell co-cultures were characterized by high IL-10, decreased IL-12p70 and IFN-γ levels, and elevated Treg population. In contrast, Lr-pulsed DC/CD4⁺ T-cell co-cultures expressed low IL-10, high IL-12p70 and IFN-γ levels and declined Treg population; this responsiveness pattern was not changed by Hp. The responsiveness pattern of the Lp/Hp-pulsed DC/CD4⁺ T-cell co-cultures did not differ from those pulsed with Hp alone.

CONCLUSION

In contrast to Lp, Lr probiotic strain overcomes Hp-mediated immune profile in the DC/T-cell co-cultures toward Th1 pattern and limited generation of Tregs in vitro. Lr may therefore be used as a component of anti-Hp treatment.

Variations in Oral Microbiota Composition Are Associated With a Risk of Throat Cancer

In this study, a next-generation sequencing strategy on 16S ribosomal RNA (16S rRNA) gene was employed to analyze 70 oral samples from 32 patients with throat cancer, nine patients with vocal cord polyp, and 29 healthy individuals (normal controls). Using this strategy, we demonstrated, for the first time, that the salivary microbiota of cancer patients were significantly different from those of patients with a polyp and healthy individuals. We observed that the beta diversity of the cancer group was divergent from both the normal and polyp groups, while alpha-diversity indices such as the Chao1 estimator (P = 8.1e-05), Simpson (P = 0.0045), and Shannon (P = 0.0071) were significantly reduced in cancer patients compared with patients containing a polyp and normal healthy individuals. Linear discriminant analysis (LDA) and Kruskal–Wallis test analyses and real-time quantitative polymerase chain reaction (qPCR) verification test revealed that the genera Aggregatibacter, Pseudomonas, Bacteroides, and Ruminiclostridium were significantly enriched in the throat cancer group compared with the vocal cord polyp and normal control groups (score value >2). Finally, diagnostic models based on putatively important constituent bacteria were constructed with 87.5% accuracy [area under the curve (AUC) = 0.875, 95% confidence interval (CI): 0.695–1]. In summary, in this study we characterized, for the first time, the oral microbiota of throat cancer patients without smoking history. We speculate that these results will help in the pathogenic mechanism and early diagnosis of throat cancer.

Lactobacillus plantarum induces apoptosis in gastric cancer cells via modulation of signaling pathways in Helicobacter pylori

Introduction: Gastric cancer is considered the second prevalent cause of death around the world. This type of cancer is generally induced by Helicobacter pylori which could colonize within the gastric mucosa of the infected cases. To date, triple antibiotic therapy has routinely been utilized for controlling the H. pylori- induced infection. However, this strategy has been unsuccessful, in large part because of issues such as occurring point mutations in the H. pylori genome that can induce resistance to the antibiotics administered. Recently, it has been shown that different probiotics may have strong anti-cancer effects, in which they are capable of inhibiting H. pylori by both immunological and non-immunological mechanisms. Here, we aimed at finding possible anti-cancer impacts of the probiotic bacterium Lactobacillus plantarum on gastric cancer, AGS cells. Methods: The anti-cancer effects of the conditioned media of the locally isolated L. plantarum on the AGS cells were evaluated by different analyses such as flow cytometry, DNA ladder assay, DAPI staining, and RT-PCR. Results: Our findings showed that the conditioned media of L. plantarum can inhibit both H. pylori and AGS cells through up-/down-regulation of PTEN, Bax, TLR4, and AKT genes. The exudates of the probiotic L. plantarum bacteria can increase the expression of PTEN, Bax, and TLR4, and also decrease the expression of AKT gene. Conclusion: In agreement with different reports, our results proved the anti-cancer effects of the locally isolated L. plantarum through some immunological cell signaling pathways. Accordingly, it seems the probiotics could be considered as at least a complementary treatment for different types of malignancies.

Proton pump inhibitors and dysbiosis: Current knowledge and aspects to be clarified

Proton pump inhibitors (PPIs) are common medications within the practice of gastroenterology. These drugs, which act through the irreversible inhibition of the hydrogen/potassium pump (H+/K+-ATPase pump) in the gastric parietal cells, are used in the treatment of several acid-related disorders. PPIs are generally well tolerated but, through the long-term reduction of gastric acid secretion, can increase the risk of an imbalance in gut microbiota composition (i.e., dysbiosis). The gut microbiota is a complex ecosystem in which microbes coexist and interact with the human host. Indeed, the resident gut bacteria are needed for multiple vital functions, such as nutrient and drug metabolism, the production of energy, defense against pathogens, the modulation of the immune system and support of the integrity of the gut mucosal barrier. The bacteria are collected in communities that vary in density and composition within each segment of the gastrointestinal (GI) tract. Therefore, every change in the gut ecosystem has been connected to an increased susceptibility or exacerbation of various GI disorders. The aim of this review is to summarize the recently available data on PPI-related microbiota alterations in each segment of the GI tract and to analyze the possible involvement of PPIs in the pathogenesis of several specific GI diseases.