Probiotics as an adjuvant treatment in Helicobacter pylori eradication therapy

Screening Probiotics for Anti-Helicobacter pylori and Investigating the Effect of Probiotics on Patients with Helicobacter pylori Infection

Probiotics are natural microbial agents with beneficial properties such as bacteriostatic and anti-infective properties. Lactobacillus plantarum Q21, Q25 and QA85, were isolated from the Chinese specialty fermented food "Jiangshui" and proved to be highly resistant to Helicobacter pylori (p < 0.0001). In vitro results showed that Q21, Q25 and QA85 strongly inhibited H. pylori and could specifically co-aggregate H. pylori in vitro (more than 56%). Strains have the potential to adhere to cells and hinder H. pylori colonization (p < 0.0001). To assess the anti-H. pylori efficacy of strains in vivo, volunteers were recruited and a self-controlled study of probiotic intervention was conducted. Compared to pre-probiotics, volunteers who took Q21, Q25 and QA85 for 1 month showed significant improvement in discomfort, a significant reduction in GSRS scores (p < 0.05), and modulation of inflammatory response (p < 0.05). Q21, Q25 and QA85 resulted in a decreasing trend of H. pylori load in volunteers (454.30 ± 327.00 vs. 328.35 ± 237.19, p = 0.06). However, the strains were not significantly effective in modulating the imbalance of the gut microbiota caused by H. pylori infection. In addition, strains affect metabolic pathways by increasing the levels of O-Phosphoethanolamine and other related metabolites, which may ameliorate associated symptoms. Therefore, Lactobacillus plantarum Q21, Q25 and QA85 can be regarded as a candidate probiotic preparation that exerts direct or indirect anti-H. pylori effects by inhibiting H. pylori activity and colonization, reducing inflammation and discomfort, maintaining homeostasis in the internal environment, affecting the metabolic pathways and repairing the body barrier. They can play a role in relieving H. pylori infection.

Role of the Microbiome in the Diagnosis and Management of Gastroesophageal Cancers

PURPOSE

Stomach and esophageal cancers are among the highest mortality from cancers worldwide. Microbiota has an interplaying role within the human gastrointestinal (GI) tract. Dysbiosis occurs when a disruption of the balance between the microbiota and the host happens. With this narrative review, we discuss the main alterations in the microbiome of gastroesophageal cancer, revealing its potential role in the pathogenesis, early detection, and treatment.

RESULTS

Helicobacter pylori plays a major role the development of a cascade of preneoplastic conditions ranging from atrophic gastritis to metaplasia and dysplasia, ultimately culminating in gastric cancer, while other pathogenic agents are Fusobacterium nucleatum, Bacteroides fragilis, Escherichia coli, and Lactobacillus. Campylobacter species (spp.)'s role in the progression of esophageal adenocarcinoma may parallel that of Helicobacter pylori in the context of gastric cancer, with other esophageal carcinogenic agents being Escherichia coli, Bacteroides fragilis, and Fusobacterium nucleatum. Moreover, gut microbiome could significantly alter the outcomes of chemotherapy and immunotherapy. The gut microbiome can be modulated through interventions such as antibiotics, probiotics, or prebiotics intake. Fecal microbiota transplantation has emerged as a therapeutic strategy as well.

CONCLUSIONS

Nowadays, it is widely accepted that changes in the normal gut microbiome causing dysbiosis and immune dysregulation play a role gastroesophageal cancer. Different interventions, including probiotics and prebiotics intake are being developed to improve therapeutic outcomes and mitigate toxicities associated with anticancer treatment. Further studies are required in order to introduce the microbiome among the available tools of precision medicine in the field of anticancer treatment.

Weizmannia coagulans BCF-01: a novel gastrogenic probiotic for Helicobacter pylori infection control

The widespread prevalence of Helicobacter pylori infection, particularly in China, contributes to the development of gastrointestinal diseases. Antibiotics have limitations, including adverse reactions and increased antibiotic resistance. Therefore, identification of novel gastrogenic probiotics capable of surviving the acidic gastric environment and effectively combating H. pylori infection has potential in restoring gastric microbiota homeostasis. Five novel strains of human gastrogenic Weizmannia coagulans (BCF-01-05) were isolated from healthy gastric mucosa and characterized using 16S rDNA identification. Acid resistance, H. pylori inhibition, and adherence to gastric epithelial cells were evaluated in in-vitro experiments and the molecular mechanism explored in in-vivo experiments. Among the gastric-derived W. coagulans strains, BCF-01 exhibited the strongest adhesion and H. pylori inhibition, warranting further in-vivo safety evaluation. Through 16S rRNA sequencing of a mouse model, BCF-01 was determined to significantly restore H. pylori-associated gastric dysbiosis and increase the abundance of potential probiotic bacteria. Furthermore, BCF-01 enhanced mucosal tight junction protein expression and inhibited the TLR4-NFκB-pyroptosis signaling pathway in macrophages, as demonstrated by qRT-PCR and western blotting.These findings highlight the potential of BCF-01 in the prevention and control of H. pylori infection. Specifically, treatment with BCF-01 effectively restored gastric microecology and improved H. pylori-mediated mucosal barrier destruction while reducing inflammation through inhibition of the TLR4-NFκB-pyroptosis signaling pathway in macrophages. BCF-01 is a promising alternative to traditional triple therapy for H. pylori infections, offering minimal side effects with high suitability for high-risk individuals.

Efficacy and safety of probiotic-supplemented bismuth quadruple therapy for the treatment of Helicobacter pylori infection: a systematic review and meta-analysis

OBJECTIVE

We performed a meta-analysis to determine whether the addition of probiotics to the bismuth quadruple therapy (BQT) for Helicobacter pylori would improve the incidence of eradication and reduce that of side effects.

METHODS

Randomized controlled trials matching the inclusion criteria were collected from PubMed, Embase, Web of Science, and The Cochrane Central Register of Controlled Trials. A Mantel-Haenszel random-effects model was used to calculate pooled risk ratios (RRs) and 95% confidence intervals (CIs) for the incidences of eradication rate, side effects as a whole, diarrhea, and other side effects.

RESULTS

Ten studies were selected for inclusion in the meta-analysis. The pooled RRs for the eradication rates in intention-to-treat and per-protocol analyses of the probiotic group vs. the control group were 1.07 (95% CI: 1.02-1.11) and 1.04 (95% CI: 1.00-1.07), respectively. Probiotic supplementation reduced the incidences of side effects (RR 0.58, 95% CI: 0.37-0.91), diarrhea (RR 0.41, 95% CI: 0.25-0.67), and bitter taste (RR 0.63, 95% CI: 0.40-0.99).

CONCLUSIONS

The results of this meta-analysis support the use of probiotics in combination with BQT in the clinical management of patients with H. pylori infection.

Efficacy of Sequential Therapy as the First-Line Treatment in the Eradication of Helicobacter pylori

The Helicobacter pylori infection is a significant issue in global health as it is associated with a range of gastrointestinal disorders and an elevated likelihood of developing stomach cancer. The declining efficacy of standard triple therapy (TT) as the recommended treatment can be attributed to the emergence of drug-resistant strains. Sequential therapy (ST) has been recognized as an alternative approach, wherein a combination of proton-pump inhibitor (PPI) and amoxicillin is administered for the initial five days, followed by a combination of PPI, clarithromycin, and metronidazole for the subsequent five days. In this comprehensive systematic review and meta-analysis, we have thoroughly assessed the effectiveness and tolerability of ST as a primary treatment option in comparison to TT for the eradication of H. pylori. The analysis comprised a total of 15 randomized controlled trials, encompassing a sample size of 5,219 patients. The collective findings indicate that ST exhibits promise as it achieves higher rates of eradication. Additionally, it is worth noting that this approach has the potential to yield cost savings and enhance treatment compliance when compared to TT. To summarize, this systematic review and meta-analysis provide evidence that ST is a viable option for the initial treatment of H. pylori eradication. It shows potential benefits compared to the standard TT, especially when there is resistance to clarithromycin. In order to establish ST as the preferred first-line treatment, it is imperative that additional research be conducted to address the aforementioned limitations and thoroughly investigate its long-term efficacy and safety profiles. Nevertheless, it is required that additional research be conducted in order to adequately tackle the constraints of the current studies and solidify its position as a favored treatment alternative. It is also essential to consider ST as a viable approach to improve the rates of H. pylori eradication. This method should be thoroughly examined in clinical practice to gain a deeper understanding of its effectiveness.

Comparative effectiveness of different probiotics supplements for triple helicobacter pylori eradication: a network meta-analysis

Background

Probiotics has been reported as an effective supplement for Helicobacter pylori eradication. However, knowledge of their comparative efficacy is still lacking.

Aim

In this study, we used network meta-analysis of current probiotics supplement used in standard triple therapy to assess and rank their comparative effectiveness.

Methods

All randomized controlled trials from three main databases (PubMed, Embase and Cochrane Library) up to April 2022 were collected and filtered to meet our criterion. We used Bayesian network meta-analysis to evaluate the eligible randomized controlled trials and gave a rank for the efficiency and incidence of side effects of each probiotics supplement. The ranking probability for each therapy was assessed by means of surfaces under cumulative ranking values. Subgroup analysis was conducted to evaluate other possible influencing factors.

Results

34 eligible randomized controlled trials entered the following meta-analysis, including 9,004 patients randomized to 10 kinds of therapies. Result showed that most probiotics added therapies had better outcomes than triple therapy, among which Bifidobacterium-Lactobacillus and Bifidobacterium-Lactobacillus-Saccharomyces adjuvant therapy could obtain comprehensive benefit with high eradication rate (78.3% and 88.2% respectively), and cause few side effects. Combination of different probiotics, adding probiotics before or after triple therapy and longer duration of probiotics can improve therapeutic effect in H.pylori infected individuals.

Conclusion

For triple therapy of H.pylori infection, adding probiotics can increase eradication rate and bring protective effect. Considering the overall influence, Bifidobacterium-Lactobacillus or Bifidobacterium-Lactobacillus-Saccharomyces therapy can be a better choice in improving H.pylori eradication process.

Current trends in <i>Helicobacter pylori</i> eradication therapy

According to the Maastricht VI consensus, the triple therapy (PPI + clarithromycin + amoxicillin) and bismuth-based quadruple therapy (PPI + bismuth + tetracycline + metronidazole) are considered and may be proscribed empirically as first-line regimens in the regions with low clarithromycin resistance rates (<15%). In the regions with high clarithromycin resistance rates (> 15%), as well as in the regions with unknown resistance to this antibacterial agent, it is recommended to use classical quadruple therapy with bismuth drugs as the main choice and quadruple therapy without bismuth drugs (“simultaneous” or “concomitant”) as an alternative. The second-line regimens of empiric choice (when antimicrobial susceptibility testing is not available) include fluoroquinolone-based quadruple therapy (PPI + levofloxacin + amoxicillin + bismuth) or fluoroquinolone-based triple therapy (PPI + levofloxacin + amoxicillin) and bismuth-based quadruple therapy. The Maastricht VI consensus regulates the use of rifabutin-based triple therapy (PPI + amoxicillin + rifabutin) as a “rescue” therapy, if the above ET schemes are ineffective and there is no possibility to conduct an antimicrobial susceptibility test. In its latest clinical guidelines, the Russian Gastroenterological Association (RGA) recommends with a view to achieving maximum treatment efficiency during classic triple ET and levelling the risk of further progression of clarithromycin resistance in Russia to take additional measures to increase its effectiveness (detailed instruction of a patient and control over strict adherence to the prescribed regimen, prolonging the course up to 14 days; prescribing PPI at increased dose twice a day; the latest generation PPIs (rabeprazole and esomeprazole); adding bismuth tripotassium dicitrate (240 mg 2 times a day) to the standard triple therapy; adding cytoprotector rebamipide (100 mg 3 times a day) to the standard triple therapy; adding a probiotic with proven efficacy to the standard triple therapy within controlled studies).

The Efficacy and Safety of Vonoprazan and Amoxicillin Dual Therapy for Helicobacter pylori Infection: A Systematic Review and Network Meta-Analysis

The eradication of Helicobacter pylori (H. pylori) infection remains challenging due to increasing bacterial resistance. Resistance rates to clarithromycin, metronidazole, and levofloxacin were higher than 30% in the USA, making current therapies less effective. Vonoprazan triple therapy (VAC) has demonstrated similar efficacy and safety profiles compared to PPI-based triple therapy (PPI). However, the eradication rate of vonoprazan dual therapy (VA) for H. pylori infection in comparison to VAC, and PPI was poorly established. Electronic databases were searched up to 6 October 2022, to identify studies examining the safety and efficacy of VA compared to VAC and PPI. Six studies were included. For empiric therapies among treatment naïve patients, VA, VAC, and PPI did not achieve high cure rates (>90%). The comparative efficacy ranking showed VAC was the most effective therapy, followed by VA, and PPI. The results were similar for clarithromycin-resistant infections. The comparative safety ranking showed VA ranked first, whereas PPI triple therapy was the least safe regimen. These findings should guide the selection of the most effective and safe treatment and conduct additional studies to determine the place of vonoprazan dual versus triple therapies in patients with H. pylori from various countries across the world.

Chemopreventive role of probiotics against cancer: a comprehensive mechanistic review

Probiotics use different mechanisms such as intestinal barrier improvement, bacterial translocation and maintaining gut microbiota homeostasis to treat cancer. Probiotics' ability to induce apoptosis against tumor cells makes them more effective to treat cancer. Moreover, probiotics stimulate immune function through an immunomodulation mechanism that induces an anti-tumor effect. There are different strains of probiotics, but the most important ones are lactic acid bacteria (LAB) having antagonistic and anti-mutagenic activities. Live and dead probiotics have anti-inflammatory, anti-proliferative, anti-oxidant and anti-metastatic properties which are useful to fight against different diseases, especially cancer. The main focus of this article is to review the anti-cancerous properties of probiotics and their role in the reduction of different types of cancer. However, further investigations are in progress to improve the efficiency of probiotics in cancer treatment.

Bacillus clausii for Gastrointestinal Disorders: A Narrative Literature Review

The gut microbiota is intrinsically linked to human health; disturbances in microbial homeostasis are implicated in both intestinal and extraintestinal disorders. Probiotics are "live microorganisms that, when administered in adequate amounts, confer a health benefit on the host," and many commercial preparations comprising a diverse range of species are available. While probiotics have been much researched, better understanding of the probiotic effects and applications of species such as Bacillus clausii is warranted. In this narrative literature review, we review the characteristics and mechanisms of action supporting B. clausii as a probiotic and discuss the evidence from clinical studies evaluating B. clausii probiotics for the management of a variety of gastrointestinal disorders and symptoms in children and adults. Finally, we highlight the challenges of future research and the need for more robust and diverse clinical evidence to guide physicians in the clinical application of probiotics for gastrointestinal disorders and other conditions.

Impact of Lactobacillus Reuteri and Three Other Probiotics in Helicobacter Pylori Eradication

Background/Objectives: To assess the effectiveness and safeness of Lactobacillus reuteri and additionally three other probiotics to conventional triple therapy against the Heliobacter pylori.Materials and Methods: We randomly selected 115 H. pylori positive dyspeptic patients, to be treated for 14 days with conventional triple therapy, without and with probiotics. Our first group of 62 patients received conventional triple therapy, while the second group of 53 patients were treated with Lactobacillus reuteri, and Lactobacillus casei, Lactobacillus acidophilus, Bifidobacterium lactis, all encapsulated in PharmaS Helicobalans capsules alongside the triple conventional therapy. One month after completion of treatment, Helicobacter pylori presence was evaluated. If the Helicobacter pylori test would turn out negative, it would prove the success of the eradication.Results: 38 patients of the first group (61,3%) were treated successfully. In the second group, where probiotics were added, the success of eradication was observed in 37 of them (69.8%).Despite the fact that eradication was higher in the second group, the difference between the two sides in terms of statistics was non-significant (p=0.199). As for the side effects of the ordered treatment, 27 patients of the first group (43.5%) had complaints, while the secondary group had 17(32%). Again, there was seen no difference statistically important between two sides.Conclusion: Including probiotics additionally to conventional Helicobacter pylori treatment may decrease the side effects of the therapy, and increase the Helicobacter pylori eradication success. Randomized prospective work on a larger scale is needed.

Quantitative and qualitative characterization of commercially available oral suspension of probiotic products containing Bacillus Clausii spores

Probiotics contain beneficial live bacteria that confer several health benefits to the host. For the past 50 years, spore-forming Bacillus species have been used in the form of probiotics. Among these, Bacillus clausii strains are used for the management of acute and antibiotic-associated diarrhoea. In the present work, we have evaluated the asserted label information on randomly chosen commercial Bacillus clausii spore suspension of probiotic products. The quality and number of viable bacteria were evaluated based on the colony count, antibiotic resistance, and hemolytic activity assays. The colony fingerprinting and 16S rRNA gene-sequencing techniques were used to confirm the presence of a univariate strain (Bacillus clausii). Our results corroborated the label count of 2 × 10⁹ CFU/5 mL in BACIPRO®, ENTEROGERMINA®, and TUFPRO® products. However, vegetative spore count was not found to match with the given label count in BENEGUT®, PROALANA-B®, β-LOCK®, and PROCILLUS® Bacillus clausii brands. In the hemolytic activity assay, except for β-LOCK®, the other 6 products showed gamma-hemolysis activity. Bacillus clausii isolated from all 7 probiotic products demonstrated resistance to several broad-spectrum antibiotics. The 16S rRNA gene-sequencing data detected genera of Bacillus and Bacillus clausii strain in the BACIPRO®, ENTEROGERMINA®, PROALANA-B®, BENEGUT®, and TUFPRO® products; however, Ralstonia mannitolilytica and Paenibacillus dendritiformis species were identified in β-LOCK® and PROCILLUS®, respectively. As correct label information was observed only in BACIPRO®, ENTEROGERMINA®, and TUFPRO® products, it is proposed that a more stringent quality check would minimize the possibility of mismatch concerning the label information.

Effectiveness of Rebamipide as a part of the <i>Helicobacter pylori</i> eradication therapy in Russia: a meta-analysis of controlled trials

Aim. To perform a meta-analysis of the data on Rebamipide efficacy and safety as a part of Helicobacter pylori eradication therapy in Russian patients. Materials and methods. A search for original studies was conducted in the electronic database of the Russian Science Citation Index (RSCI) on the Scientific Electronic Library (SEL Elibrary.ru). Google (Google.com) was used for the "grey" search. All Russian controlled studies comparing the efficacy and/or safety of Rebamipide as a part of the regimen of H. pylori eradication therapy were included in the final analysis. Results. In 6 included controlled trials with a cumulative population (considering double comparisons between multiple groups) of 531 patients (273 in Rebamipide groups and 258 in groups without Rebamipide), the pooled eradication effectiveness was 90.376% (95% confidence interval CI 86.31193.560) in patients receiving Rebamipide and 81.681% (95% CI 76.49986.141) in patients receiving eradication regimens without Rebamipide. The meta-analysis showed that the Rebamipide addition to eradication regimens significantly improved efficacy (odds ratio 2.162, 95% CI 1.2683.685; p=0.005). No significant heterogeneity was found between study results (p=0.863; I2=0.00%); therefore, a fixed effects model was used in the resulting analysis. In addition, the meta-analysis of included studies showed a reduction of adverse events (odds ratio 0.569, 95% CI 0.3330.970) in the groups receiving Rebamipide; p=0.038). This effect of Rebamipide deserves special attention and requires additional study, as the result was at the border of statistical significance in the subanalysis of three studies with a large margin of risk reduction in one of them (with the largest sample of patients). Conclusion. The present meta-analysis demonstrated that the Rebamipide addition to H. pylori eradication regimens significantly improves the treatment effectiveness in the Russian patient population.

Evaluation of IR Biotyper for Lactiplantibacillus plantarum Typing and Its Application Potential in Probiotic Preliminary Screening

IR Biotyper (IRBT), which is a spectroscopic system for microorganism typing based on Fourier transform infrared (FTIR) technology, has been used to detect the spread of clones in clinical microbiology laboratories. However, the use of IRBT to detect probiotics has rarely been reported. Herein, we evaluated the discriminatory power of IRBT to type Lactiplantibacillus plantarum isolates at the strain level and explored its application potential in probiotic preliminary selection. Twenty Lactiplantibacillus isolates collected from pickled radishes during successive fermentation were used to test the robustness of IRBT at the strain level. IRBT was then compared with genotyping methods such as whole-genome sequencing (WGS), pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST) to evaluate its discrimination power. IRBT distributed the 20 isolates into five clusters, with L. argentoratensis isolate C7-83 being the most distant from the other isolates, which belonged to L. plantarum. IRBT showed good reproducibility, although deviation in the discriminative power of IRBT was found at the strain level across laboratories, probably due to technical variance. All examined methods allowed bacterial identification at the strain level, but IRBT had higher discriminatory power than MLST and was comparable to the WGS and PFGE. In the phenotypic comparison study, we observed that the clustering results of probiotic physiological attributes (e.g., sensitivity to acid and bile salts, hydrophobicity of the cell surface, and resistance to antibiotics) were consistent with the typing results of IRBT. Our results indicated that IRBT is a robust tool for L. plantarum strain typing that could improve the efficiency of probiotic identification and preliminary screening, and can potentially be applied in probiotic traceability and quality control.

The impacts of probiotics in eradication therapy of Helicobacter pylori

Helicobacter pylori (H. pylori) is a well-known pathogen that infects approximately half of the world's population. It is a pathogenic agent with potential health hazards related to diverse diseases, especially digestive diseases, such as chronic gastritis, peptic ulcer, and gastric carcinoma. In clinical, antibiotics are commonly applied in eradication therapy of H. pylori. However, the increase in antibiotic resistance and side effects has induced the failure of eradication therapy. Recent studies have shown that probiotic supplementation has promising application prospects. It can restore the gastrointestinal microbiota balance and prevent dysbacteriosis caused by antibiotics. Furthermore, it has been reported to have direct or indirect inhibitory effects on H. pylori. Probiotics may have a beneficial effect on H. pylori eradication. However, the strain, dosages, duration times, and safety of probiotic supplementation need further study before clinical applications.

Fermented kimchi rejuvenated precancerous atrophic gastritis via mitigating Helicobacter pylori-associated endoplasmic reticulum and oxidative stress

Dietary intervention to prevent Helicobacter pylori (H. pylori)-gastric cancer might be ideal by long-term intervention, rejuvenating action, and no risk of bacterial resistance. Stimulated with finding that kimchi prevented H. pylori-gastric cancer, we compared the efficacy of cancer preventive kimchi (cpkimchi) and standard recipe kimchi (skimchi) and the efficacy between fermented kimchi and non-fermented kimchi (kimuchi) in H. pylori-initiated gastric cancer model and explored novel mechanisms hinted from RNAseq transcriptome analysis. Animal models assessing gastric pathology on 24 and 36 weeks after H. pylori initiated, salt diet-promoted gastric mutagenesis model showed fermented cpkimchi afforded the best outcome of either rejuvenating atrophic gastritis or inhibiting tumorigenesis compared to skimchi and kimuchi. Highest inhibition of atrophic gastritis was achieved with cpkimchi, while significantly lower in kimuchi. Transcriptomic analysis showed ameliorated-endoplasmic reticulum (ER) stress, -oxidative stress, and -apoptosis as major rejuvenating action of cpkimchi. Homogenates from animal model showed that elevated expressions of p-PERK, IRE, ATF6, p-elf, and XBP1 in control group, while significantly decreased with dietary intake of only cpkimchi. Significantly increased expressions of HO-1 and γ-GCS were only noted with cpkimchi. Conclusively, long-term dietary intervention of fermented cpkimchi can be potential way preventing H. pylori-associated carcinogenesis via rejuvenation of atrophic gastritis.

Clinical Relevance of Helicobacter pylori Infection

Helicobacter pylori (H. pylori) is a Gram-negative helical, microaerophilic bacterium which colonizes the antrum and body of the stomach, surviving in its harsh environment through mechanisms of acid resistance and colonization factors. It infects approximately 50% of the world population. Although the prevalence of this infection varies from country to country, as well as between different ethnic, social or age groups, it is estimated that about 50% of the human population only carries this microorganism. While H. pylori has been found to play a major etiological and pathogenic role in chronic gastritis, peptic ulcer disease and gastric cancer, its importance for many types of extra-gastric disease needs to be further investigated. The choice of tests to diagnose H. pylori infection, defined as invasive or non-invasive, depends on the clinical indication as to whether to perform upper gastrointestinal endoscopy. Focusing on bacterial eradication, the treatment should be decided locally based on the use of antibiotics and documented antibiotic resistance. The author provides an overview of the current state of knowledge about the clinical aspects of H. pylori infection, especially its diagnostic and therapeutic management.

Current status of probiotics for prevention and management of gastrointestinal cancers

INTRODUCTION

Gastrointestinal cancers contribute to a significant number of cancer- associated mortality. The gastrointestinal tract harbors a multitude of microorganisms, known as the microbiota. Recently, the microbiota is considered to be an accessory organ resulting in several health benefits. The microbiota is involved in almost all aspects of an individual ranging from managing behavior to controlling metabolism, immune status and the response to a disease. Researchers are observing the modulation of microbiota in almost every disease, including cancer. Probiotics are microorganisms that can help to alter the host microbiota toward a healthy state thus providing benefits from many diseases including cancer.

AREAS COVERED

We explored the current status of the use of probiotics in cancer patients. Although probiotic bacteria can provide significant benefits to individuals suffering from cancer, the number of cancer-specific clinical products containing probiotics is not comparable to research studies showing their benefits. The lack of available products is due to several factors including a lack of risk assessment data of beneficial probiotics in cancer patients.

EXPERT OPINION

Laboratory investigations indicate a huge potential of probiotics for the prevention and management of gastrointestinal cancer, but more clinical studies are required to support their application in clinical settings.

The Bacterial Microbiota of Gastrointestinal Cancers: Role in Cancer Pathogenesis and Therapeutic Perspectives

The microbiota has an essential role in the pathogenesis of many gastrointestinal diseases including cancer. This effect is mediated through different mechanisms such as damaging DNA, activation of oncogenic pathways, production of carcinogenic metabolites, stimulation of chronic inflammation, and inhibition of antitumor immunity. Recently, the concept of "pharmacomicrobiomics" has emerged as a new field concerned with exploring the interplay between drugs and microbes. Mounting evidence indicates that the microbiota and their metabolites have a major impact on the pharmacodynamics and therapeutic responses toward anticancer drugs including conventional chemotherapy and molecular-targeted therapeutics. In addition, microbiota appears as an attractive target for cancer prevention and treatment. In this review, we discuss the role of bacterial microbiota in the pathogenesis of different cancer types affecting the gastrointestinal tract system. We also scrutinize the evidence regarding the role of microbiota in anticancer drug responses. Further, we discuss the use of probiotics, fecal microbiota transplantation, and antibiotics, either alone or in combination with anticancer drugs for prevention and treatment of gastrointestinal tract cancers.

Survivability of alginate-microencapsulated Lactobacillus plantarum during storage, simulated food processing and gastrointestinal conditions

A comparison between the most investigated alginate-based encapsulating agents was performed in the current study. Here, the survivability of Lactobacillus plantarum microencapsulated with alginate (Alg) combined with skim milk (Sm), dextrin (Dex), denatured whey protein (DWP) or coated with chitosan (Ch) was evaluated after exposure to different heat treatments and in presence of some food additives, during storage and under simulated gastrointestinal condition. In addition, the encapsulated cells were evaluated for production of different bioactive compounds such as exopolysacchar. ides and antimicrobial substances compared with the unencapsulated cells. The results showed that only Alg-Sm maintained the viability of the cells >106 cfu/g at the pasteurization temperature (65 °C for 30 min). Interestingly, storage under refrigeration conditions increased the viability of L. plantarum entrapped within all the tested encapsulating agents for 4 weeks. However, under freezing condition, only Alg-DWP and Alg-Sm enhanced the survival of the entrapped cells for 3 months. All the microencapsulated cells were capable of growing at the different NaCl concentrations (1%-5%) except for cells encapsulated with Alg-Dex, showed viability loss at 3% and 5% NaCl concentrations. Tolerance of the microencapsulated cells toward organic acids was varied depending on the type of organic acid. Alg-Ch and Alg-Sm provide better survival for the cells under simulated gastric juice; however, all offer a good survival for the cells under simulated intestinal condition. Our findings indicated that Alg-Sm proved to be the most promising encapsulating combination that maintains the survivability of L. plantarum to the recommended dose level under almost all the stress conditions adopted in the current study. Interestingly, the results also revealed that microencapsulation does not affect the metabolic activity of the entrapped cells and there was no significant difference in production of bioactive compounds between the encapsulated and the unencapsulated cells.

Pathogenesis and clinical management of Helicobacter pylori gastric infection

Helicobacter pylori (H. pylori) is a gram-negative bacterium that infects approximately 4.4 billion individuals worldwide. However, its prevalence varies among different geographic areas, and is influenced by several factors. The infection can be acquired by means of oral-oral or fecal-oral transmission, and the pathogen possesses various mechanisms that improve its capacity of mobility, adherence and manipulation of the gastric microenvironment, making possible the colonization of an organ with a highly acidic lumen. In addition, H. pylori presents a large variety of virulence factors that improve its pathogenicity, of which we highlight cytotoxin associated antigen A, vacuolating cytotoxin, duodenal ulcer promoting gene A protein, outer inflammatory protein and gamma-glutamyl transpeptidase. The host immune system, mainly by means of a Th1-polarized response, also plays a crucial role in the infection course. Although most H. pylori-positive individuals remain asymptomatic, the infection predisposes the development of various clinical conditions as peptic ulcers, gastric adenocarcinomas and mucosa-associated lymphoid tissue lymphomas. Invasive and non-invasive diagnostic methods, each of them with their related advantages and limitations, have been applied in H. pylori detection. Moreover, bacterial resistance to antimicrobial therapy is a major challenge in the treatment of this infection, and new therapy alternatives are being tested to improve H. pylori eradication. Last but not least, the development of effective vaccines against H. pylori infection have been the aim of several research studies.

Efficiency of the Inclusion of Rebamipide in the Eradication Therapy for Helicobacter pylori Infection: Meta-Analysis of Randomized Controlled Studies

Background: There has been a negative trend in the effectiveness of classic eradication therapy regimens for Helicobacter pylori (H. pylori), which has largely been determined from the emergence and spread of antibiotic resistance. Several studies have shown that adding rebamipide to eradication regimens leads to an increase in the effectiveness of treatment. Aim: To evaluate the efficacy and safety of including rebamipide in the eradication regimens for H. pylori infection. Methods: The literature search was conducted in the MEDLINE/PubMed, EMBASE, Cochrane Central Register, Korean Medical Citation Index, and Russian Science Citation Index databases. All identified randomized controlled trials comparing rebamipide supplementation with non-rebamipide-containing eradication regimens for the treatment of H. pylori infection were included in the final analysis. Results: We identified 11 randomized controlled trials (RCTs) involving 1227 patients (631 in groups with rebamipide and 596 in groups without rebamipide). The meta-analysis showed that the addition of rebamipide to eradication regimens significantly increased the effectiveness of treatment (odds ratio (OR) 1.753, 95% confidence interval (CI) 1.312–2.333, p < 0.001). The subgroup analysis demonstrated that rebamipide significantly increased the effectiveness of eradication when added to a dual therapy regimen (OR 1.766, 95% CI: 1.167–2.495, p = 0.006); however, no significant improvement in effectiveness was observed when it was added to the triple therapy regimen (OR 1.638, 95% CI 0.833–3.219, p = 0.152). Conclusion: This meta-analysis demonstrated that the addition of rebamipide to H. pylori eradication regimens significantly increases the effectiveness of treatment.

The effect of Lactobacillus reuteri supplementation in Helicobacter pylori infection: a placebo-controlled, single-blind study

Background

Helicobacter pylori is the major cause of chronic gastritis, and considered as a risk factor for peptic ulcer and gastric cancer. The H. pylori standard antibiotic therapy fails in about 25–30% of cases, particularly because of the increasing occurrence of resistance to antibiotics. The aim of the current study was to investigate whether the strain Lactobacillus reuteri DSM17648 which has been previously shown to reduce Helicobacter pylori load additionally improves gastrointestinal symptoms in H. pylori positive subjects when used in a 28 days supplementation.

Methods

In a single-blinded, placebo controlled study 24 H. pylori-positive adults (13 females, 11 males; median age: 43.5) with mild dyspepsia (mean GSRS score: 11.82) received placebo for 28 days followed by Pylopass™ containing the L. reuteri DSM 17648 (2 × 10¹⁰ cells per day) for the following 28 days. After 28 days of Pylopass™ supplementation the change in H. pylori load was measured by ¹³C urea breath test (¹³C-UBT) and the change in symptoms were determined by the Gastrointestinal Symptom Rating Scale (GSRS). In addition, blood assessments were conducted to measure the physiological changes relevant in terms of safety.

Results

After a 28-day supplementation phase with Pylopass™ there was a trend for reduction of H. pylori load in 62.5% of the subjects and for the overall GSRS scores in 66.7% of subjects. The overall GSRS scores from baseline to day 56 following all 24 subjects undergoing the placebo phase followed by the Pylopass™ phase was significantly decreased (p = 0.005). The mean 13C-UBT δ value decreased by 22.5% during the Pylopass™ supplementation phase (− 3.14), while the mean 13C-UBT δ increased by 37.3% (+ 3.79) in the placebo phase. No side effects were reported in either study phase.

Conclusion

The results demonstrated that L. reuteri DSM17648 has the potential to suppress H. pylori infection, and may lead to an improvement of H. pylori-associated gastro intestinal symptoms. Further studies with adequate power should be performed.

Trial registration

Clinicaltrials.gov: NCT02051348 (January 30, 2014).