Probiotic suppression of the H. pylori-induced responses by conjugated linoleic acids in a gastric epithelial cell line

Inhibitory activity of Limosilactobacillus reuteri isolated from camel milk against Helicobacter pylori effects in human gastric epithelial cells

This study aimed to evaluate anti-Helicobacter pylori effects of Limosilactobacillus reuteri 2892 (L. reuteri 2892) isolated from camel milk in GC cell lines (AGS and MKN). From 15 camel milk samples, 132 microbial strains were isolated. Based on microbial and biochemical analysis, 11 potential probiotic candidates were selected. The potential probiotic candidates were assayed for anti-H. pylori activity, and the strain with the highest anti-H. pylori activity was identified genotypically. Based on 16S rDNA sequencing, the selected strain with the best activity against H. pylori (inhibition zone = 15.5 ± 0.8) belonged to the Lactobacillus reuteri strain 2892. Cell treatment with H. pylori HC-113 inhibits gene expression of Claudin-4, ZO-1, MUC5AC, and MUC2 in gastric cells, which are attenuated by L. reuteri 2892. The simulative effects of H. pylori HC-113 on the cell migration and invasion of gastric cells were lost when cells were cotreated with L. reuteri 2892. Cell treatment with H. pylori HC-113 promoted cell death, whereas cotreatment with L. reuteri 2892 markedly decreased necrotic and late apoptotic cells. The present study demonstrates that L. reuteri 2892 has potent anti-H. pylori effects and thus can be considered as an alternative protective agent against inflammatory effects of H. pylori in gastric cells.

Lactobacillus acidophilus NCFM and Lactiplantibacillus plantarum Lp-115 inhibit Helicobacter pylori colonization and gastric inflammation in a murine model

Purpose

To determine the role of Lactobacillus strains and their combinations in inhibiting the colonization of H. pylori and gastric mucosa inflammation.

Methods

Human gastric adenocarcinoma AGS cells were incubated with H. pylori and six probiotic strains (Lactobacillus acidophilus NCFM, L. acidophilus La-14, Lactiplantibacillus plantarum Lp-115, Lacticaseibacillus paracasei Lpc-37, Lacticaseibacillus rhamnosus Lr-32, and L. rhamnosus GG) and the adhesion ability of H. pylori in different combinations was evaluated by fluorescence microscopy and urease activity assay. Male C57BL/6 mice were randomly divided into five groups (uninfected, H. pylori, H. pylori+NCFM, H. pylori+Lp-115, and H. pylori+NCFM+Lp-115) and treated with two lactobacilli strains (NCFM and Lp-115) for six weeks. H. pylori colonization and tissue inflammation statuses were determined by rapid urease test, Hematoxylin-Eosin (HE) staining, immunohistochemistry, and qRT-PCR and ELISA.

Results

L. acidophilus NCFM, L. acidophilus La-14, L. plantarum Lp-115, L. paracasei Lpc-37, L. rhamnosus Lr-32, and L. rhamnosus GG reduced H. pylori adhesion and inflammation caused by H. pylori infection in AGS cells and mice. Among all probiotics L. acidophilus NCFM and L. plantarum, Lp-115 showed significant effects on the H. pylori eradication and reduction of inflammation in-vitro and in-vivo. Compared with the H. pylori infection group, the mRNA and protein expression levels of IL-8 and TNF-α in the six Lactobacillus intervention groups were significantly reduced. The changes in the urease activity (ureA and ureB) for 1-7h in each group showed that L. acidophilus NCFM, L. acidophilus La-14, L. plantarum Lp-115, and L. rhamnosus GG effectively reduced the colonization of H. pylori. We observed a higher ratio of lymphocyte and plasma cell infiltration into the lamina propria of the gastric mucosa and neutrophil infiltration in H. pylori+NCFM+Lp-115 mice. The infiltration of inflammatory cells in lamina propria of the gastric mucosa was reduced in the H. pylori+NCFM+Lp-115 group. Additionally, the expression of IFN-γ was decreased significantly in the NCFM and Lp-115 treated C57BL/6 mice.

Conclusions

L. acidophilus NCFM and L. plantarum Lp-115 can reduce the adhesion of H. pylori and inhibit the gastric inflammatory response caused by H. pylori infection.

Probiotics for the Treatment of Gastric Diseases

Common gastric diseases include chronic gastritis, gastric ulcers and gastric cancer. The etiology of gastric diseases is complicated, including genetics, diet, excessive smoking and drinking, environmental factors, and bacterial infections. As live microorganisms, probiotics can confer health benefits to the host. At present, probiotics have been widely used in the preparation of foods, health products, and medicines. Due to their positive effects in improving diarrhea, constipation, alleviating allergies, enhancing immunity, and maintaining intestinal homeostasis, studies worldwide have focused on whether probiotics also provide therapeutic effects on gastric diseases. Thus, this review summarizes the possible mechanism of probiotics in the treatment of gastric diseases and provides a reference for expanding not only their application but also that of other microecological agents.

Efficacy of second-line regimens for Helicobacter pylori eradication treatment: a systemic review and network meta-analysis

Background

Current guidelines recommend bismuth-containing quadruple therapy (BQT) and quinolone-containing therapy after failure of first-line Helicobacter pylori eradication therapy. However, the optimum regimen of second-line eradication therapy remains elusive. We conducted a network meta-analysis to compare the relative efficacy of 16 second-line H. pylori eradication regimens.

Methods

Three major bibliographic databases were reviewed to enrol relevant randomised controlled trials between January 2000 and September 2018. Network meta-analysis was conducted by STATA software and we performed subgroup analysis in countries with high clarithromycin resistance and high levofloxacin resistance, and in patients with documented failure of first-line triple therapy.

Results

Fifty-four studies totalling 8752 participants who received 16 regimens were eligible for analysis. Compared with a 7-day BQT, use of probiotic add-on therapy during, before, and after second-line antibiotic regimens, quinolone-based sequential therapy for 10–14 days, quinolone-based bismuth quadruple therapy for 10–14 days, bismuth quadruple therapy for 10–14 days, and quinolone-based triple therapy for 10–14 days were significantly superior to the other regimens. Subgroup analysis of countries with high clarithromycin resistance and high levofloxacin resistance revealed that the ranking of second-line eradication regimens was distributed similarly in each group, as well as in patients with failure of first-line triple therapy.

Conclusion

We conducted a detailed comparison of second-line H. pylori regimens according to different antibiotic resistance rates and the results suggest alternative treatment choices with potential benefits beyond those that could be achieved using salvage therapies recommended by guidelines.

Efficacy of Probiotic Supplementation Therapy for Helicobacter pylori Eradication: A Meta-Analysis of Randomized Controlled Trials

Background

Traditional Helicobacter pylori (H. pylori) eradication therapies have shown efficacies below 80% in several studies, and their use has been accompanied by antibiotic-related side effects. Some recent studies have reported that supplementing standard therapies with probiotics can improve the efficacy and tolerability of Helicobacter pylori eradication therapy.

Objective

To assess the effects of probiotic supplementation on the eradication rates and therapy-related adverse event rates of anti-Helicobacter pylori regimens.

Methods

We searched PubMed, Medline, the Cochrane Central Registry of Controlled Trials and the Chinese Biomedical Database for eligible randomized controlled trials published through July, 2015. Review Manager 5.3 was used for all statistical analyses.

Results

Thirteen randomized controlled trials involving a total of 2306 patients were included in our analysis. Intent-to-treat (ITT) analysis performed using a fixed-effects model (test for heterogeneity I² = 45%) showed that the pooled relative risk (RR) of eradication was significantly higher in the probiotic supplementation group than in the control group [RR 1.15, 95% confidence interval (CI): 1.10–1.20, P<0.00001]. The incidence of total antibiotic-related side effects was lower in the probiotic supplementation group than in the control group, and the pooled RR (studies n = 9) was 0.71 (95% CI: 0.54–0.94, P = 0.02), as determined using a random-effects model (heterogeneity test I² = 59%). Certain adverse events, such as nausea and vomiting (RR = 0.58, 95% CI 0.35–0.95, P = 0.03), diarrhea (RR = 0.51, 95% CI: 0.31–0.84, P = 0.008) and constipation (RR = 0.47, 95% CI: 0.28–0.80, P = 0.005), were reported at lower rates in the probiotic supplementation group than in the control group. Subgroup analysis showed that eradication rates were significantly improved in both adults (RR = 1.14, 95% CI: 1.09–1.19, P<0.00001) and children (RR = 1.24, 95% CI: 1.05–1.47, P = 0.01) in the probiotic supplementation group and that no regional differences between Europe (RR = 1.17, 95% CI: 1.09–1.24, P<0.00001) and Asia were present (RR = 1.14, 95% CI: 1.06–1.22, P = 0.0002). However, the total adverse event rate was not decreased in the adult group (RR = 0.80, 95% CI: 0.61–1.04, P = 0.1) or the Asian group (RR = 0.68, 95% CI: 0.39–1.18, P = 0.17). Subgroup analyses examining therapy regimens and treatment durations showed that probiotic supplementation increased eradication rates in the triple-therapy (RR = 1.18, 95% CI: 1.12–1.25, P<0.00001), seven-day treatment (RR = 1.21, 95% CI: 1.12–1.31, P<0.00001) and fourteen-day treatment (RR = 1.13, 95% CI: 1.06–1.20, P = 0.0002) groups. The incidence of antibiotic-related side effects was significantly reduced in all groups, with the exception of the quadruple-therapy subgroup (RR = 1.13, 95% CI: 0.60–2.13, P = 0.07) and the fourteen-day therapy subgroup (RR = 0.96, 95% CI 0.61–1.51, P = 0.86). Supplementation with Lactobacillus alone (RR = 1.24, 95% CI: 1.12–1.38, P<0.0001) or multi-strain probiotics (RR = 1.12, 95% CI 1.07–1.18, P<0.00001) was effective at improving H. pylori eradication rates. However, supplementation with Lactobacillus alone did not significantly decrease the overall incidence of side effects (RR = 0.61, 95% CI: 0.11–3.51, P = 0.58). Our study also showed that probiotic supplementation before, during or after H. pylori eradication therapy improved eradication rates, regardless of supplementation duration. Furthermore, probiotic supplementation during H. pylori treatment reduced the incidence of side effects.

Conclusion

Probiotic supplementation during anti-Helicobacter pylori treatment may be effective for improving H. pylori eradication rates, minimizing the incidence of therapy-related adverse events and alleviating most disease-related clinical symptoms. However, our results should be interpreted with caution because of the presence of heterogeneity across the trials included in this analysis.

Potential role of probiotics in the management of gastric ulcer

Gastric ulcer is one of the most common chronic gastrointestinal diseases characterized by a significant defect in the mucosal barrier. Helicobacter pylori (H. pylori) infection and the frequent long-term use of non-steroidal anti-inflammatory drugs are major factors involved in gastric ulcer development. Acid inhibitors and antibiotics are commonly used to treat gastric ulcer. However, in the last few decades, the accumulating evidence for resistance to antibiotics and the side effects of antibiotics and acid inhibitors have drawn attention to the possible use of probiotics in the prevention and treatment of gastric ulcer. Probiotics are live microorganisms that when administered in adequate amounts confer health benefits on the host. Currently, the available experimental and clinical studies indicate that probiotics are promising for future applications in the management of gastric ulcers. This review aims to provide an overview of the general health benefits of probiotics on various systemic and gastrointestinal disorders with a special focus on gastric ulcer and the involved cellular and molecular mechanisms: i) Protection of gastric mucosal barrier; ii) upregulation of prostaglandins, mucus, growth factors and anti-inflammatory cytokines; iii) increased cell proliferation to apoptosis ratio; and iv) induction of angiogenesis. Finally, some of the available data on the possible use of probiotics in H. pylori eradication are discussed.

Use of probiotics in the fight against Helicobacter pylori

After the discovery of Helicobacter pylori (H. pylori), and the evidence of its relationship with gastric diseases, antibiotic-based therapies were developed, which efficacy was however limited by antibiotic resistance and lack of patient compliance. A vaccine would overcome these drawbacks, but currently there is not any H. pylori vaccine licensed. In the frame of the studies aimed at finding alternative therapies or at increasing the efficacy of the current ones and/or reducing their side effects, the investigation on the use of probiotics plays an interesting role. In vitro and preclinical studies have shown the feasibility of this approach. Several clinical trials indicated that administration of probiotics can reduce the side effects of H. pylori eradication treatment, increasing tolerability, and often increases the overall efficacy. The results of these trials vary, likely reflecting the variety of probiotics assessed and that of the eradication treatment, as well as the differences in the geographic area that imply different H. pylori strains distribution, host susceptibility, and therapy efficacy. In conclusion, the use of probiotics appears promising as an adjuvant for the current H. pylori eradication treatment, though it still requires optimization.

Helicobacter pylori and interleukin-8 in gastric cancer

Helicobacter pylori (H. pylori) is a major etiological factor in the development of gastric cancer. Large-scale epidemiological studies have confirmed the strong association between H. pylori infection and both cancer development and progression. Interleukin-8 (IL-8) is overexpressed in gastric mucosa exposed to H. pylori. The expression of IL-8 directly correlates with a poor prognosis in gastric cancer. IL-8 is multifunctional. In addition to its potent chemotactic activity, it can induce proliferation and migration of cancer cells. In this review, we focus on recent insights into the mechanisms of IL-8 signaling associated with gastric cancer. The relationship between IL-8 and H. pylori is discussed. We also summarize the current therapeutics against IL-8 in gastric cancer.

Mechanisms underlying role of probiotics in recovering Helicobacter pylori-associated intestinal mucosal barrier damage

Helicobacter pylori (H. pylori) is closely associated with many gastrointestinal diseases, including peptic ulcers, chronic gastritis, gastric cancer and gastric mucosa-associated lymphoid tumors. In recent year, traditional triple therapy for H. pylori eradication has become less effective than the past, which is related to the resistance of bacteria. The addition of probiotics into the regimen has been proved to be able to significantly enhance the eradication rate and reduce side effects. Probiotics increase the eradication of H. pylori by recovering the damage of the chemical barrier, biological barrier, mechanical barrier and immune barrier.

Crosstalk between Helicobacter pylori and gastric epithelial cells is impaired by docosahexaenoic acid

H. pylori colonizes half of the world's population leading to gastritis, ulcers and gastric cancer. H. pylori strains resistant to antibiotics are increasing which raises the need for alternative therapeutic approaches. Docosahexaenoic acid (DHA) has been shown to decrease H. pylori growth and its associated-inflammation through mechanisms poorly characterized. We aimed to explore DHA action on H. pylori-mediated inflammation and adhesion to gastric epithelial cells (AGS) and also to identify bacterial structures affected by DHA. H. pylori growth and metabolism was assessed in liquid cultures. Bacterial adhesion to AGS cells was visualized by transmission electron microscopy and quantified by an Enzyme Linked Immunosorbent Assay. Inflammatory proteins were assessed by immunoblotting in infected AGS cells, previously treated with DHA. Bacterial total and outer membrane protein composition was analyzed by 2-dimensional gel electrophoresis. Concentrations of 100 µM of DHA decreased H. pylori growth, whereas concentrations higher than 250 µM irreversibly inhibited bacteria survival. DHA reduced ATP production and adhesion to AGS cells. AGS cells infected with DHA pre-treated H. pylori showed a 3-fold reduction in Interleukin-8 (IL-8) production and a decrease of COX2 and iNOS. 2D electrophoresis analysis revealed that DHA changed the expression of H. pylori outer membrane proteins associated with stress response and metabolism and modified bacterial lipopolysaccharide phenotype. As conclusions our results show that DHA anti-H. pylori effects are associated with changes of bacteria morphology and metabolism, and with alteration of outer membrane proteins composition, that ultimately reduce the adhesion of bacteria and the burden of H. pylori-related inflammation.