Non-viable Lactobacillus reuteri DSMZ 17648 (Pylopass™) as a new approach to Helicobacter pylori control in humans

Effects of Lactobacillus spp. on Helicobacter pylori: A Promising Frontier in the Era of Antibiotic Resistance

Helicobacter pylori, a pathogenic bacterium responsible for multiple gastrointestinal disorders, has emerged as a major global concern due to rise in antibiotic resistance. Unwanted side effects of antibiotics therapy are further complicating the treatment strategies. Consequently, an alternative approach, using probiotics has emerged as a promising solution for treating H. pylori infections. Probiotics have shown considerable potential in increasing the cure rate and reducing the side effects through diverse mechanisms. Among the widely employed probiotics, Lactobacillus spp. has garnered particular attention in this review. After reviewing the studies on effects of Lactobacillus spp. on H. pylori, it is evident that several Lactobacillus spp. have demonstrated their potential efficacy against H. pylori infection, when administered alone or in conjunction with antibiotics, in a strain-specific manner. Furthermore, the inclusion of Lactobacillus spp. in the treatment regimen has also been associated with a reduction in the side effects related to antibiotic-based therapies. Future research may focus on identifying optimal strains and treatment regimens, understanding the long-term impacts of use, and determining their role in preventing H. pylori infection in various populations.

Efficacy and Safety of Postbiotic Contained Inactivated Lactobacillus reuteri ( Limosilactobacillus reuteri ) DSM 17648 as Adjuvant Therapy in the Eradication of Helicobacter pylori in Adults With Functional Dyspepsia: A Randomized Double-Blind Placebo-Controlled Trial

INTRODUCTION

Increasing the effectiveness of eradication therapy is an important task in gastroenterology. The aim of this study was to evaluate the efficacy and safety of postbiotic containing inactivated (nonviable) Limosilactobacillus (Lactobacillus) reuteri DSM 17648 (Pylopass) as adjuvant treatment of Helicobacter pylori eradication in patients with functional dyspepsia (FD).

METHODS

This randomized, double-blind, placebo-controlled, multicenter, parallel study included H. pylori -positive patients with FD. The postbiotic group received Pylopass 200 mg bid for 14 days in combination with eradication therapy (esomeprazole 20 mg bid + amoxicillin 1,000 mg bid + clarithromycin 500 mg bid for 14 days) and another 14 days after the completion of eradication therapy. The study was registered in the ISRCTN registry (ISRCTN20716052).

RESULTS

Eradication efficiency was 96.7% for the postbiotic group vs 86.0% for the placebo group ( P = 0.039). Both groups showed significant improvements in quality of life and reduction of most gastrointestinal symptoms with no significant differences between groups. The overall number of digestive adverse effects in the postbiotic group was lower than in the placebo group. Serious adverse effects were not registered.

DISCUSSION

The postbiotic containing inactivated L. reuteri DSM 17648 significantly improves the effectiveness of H. pylori eradication therapy in FD and decreases overall number of digestive adverse effects of this therapy.

Role of probiotic as adjuvant in treating various infections: a systematic review and meta-analysis

BACKGROUND

Research on the advantages of probiotics has attracted increasing interest based on the number of publications, products, and public awareness of their benefits. This review evaluated the role of probiotics (single and multiple regimens) as an additional regimen to treat common infectious diseases, including Helicobacter. pylori, diarrheal infections, urinary tract infections (UTIs), upper respiratory tract infections (URTIs), and HIV infections.

METHODS

We searched randomized controlled trials from PubMed, Scopus, Embase, and Cochrane and identified 6,950 studies. Duplicates were removed, and titles and abstracts were filtered. Bias was evaluated using the Cochrane Risk of Bias Tool for Randomized Trials (ROB 1.0 and 2.0). The certainty of the evidence was evaluated using GRADE. Data were extracted and meta-analysis was performed using RevMan.

RESULTS

A total of 32 studies were included in this study (22 H. pylori studies, 2 diarrheal infection studies, 6 UTI studies, and 2 HIV infection studies). There was no study on URTI. Probiotics, in addition to primary treatment, could improve the eradication of H. pylori versus the control (RR: 1.09; 95% CI:1.04 - 1.13, p value = 0.001) and achieve a cure range of Nugent score in UTI patients (RR 1.38; 95% CI: 1.01 - 1.89, p value = 0.04). For eradicating H. pylori infection, subgroup analysis based on the therapy regimen showed that standard triple therapy was slightly superior compared to quadruple therapy in eradicating H. pylori (RR: 1.14 vs. 1.01, respectively). Single strain probiotics showed a similar effect to multiple strain probiotic regimens (both had an RR of 1.09). The effect estimates of the use of single strain probiotics as adjuvant therapy in eradicating H. pylori and the use of probiotics in UTI had a high certainty of evidence. Meta-analysis was not performed for infectious diarrheal because there were only two eligible studies with different probiotic supplementations and outcome parameters. Nonetheless, they showed that the diarrheal incidence was lower and complete remission of diarrheal was higher after the regimen of probiotics. Similarly, a meta-analysis was not performed for HIV infection because the two eligible studies used different designs and comparators with contradicting findings.

CONCLUSION

This meta-analysis showed beneficial use of single strain probiotics as adjuvant therapy in eradicating H. pylori and the use of probiotics in UTI. Probiotic supplementation might not be beneficial for patients given a quadruple therapy. Single-strain and multi-strain probiotic regimens had similar effects in increasing the eradication rate of H. pylori. Our study also suggested that the benefits of probiotics as an additional regimen in infectious diarrheal and HIV infections remain unclear; more studies are needed to confirm the benefits.

Unlocking the power of postbiotics: A revolutionary approach to nutrition for humans and animals

Postbiotics, which comprise inanimate microorganisms or their constituents, have recently gained significant attention for their potential health benefits. Extensive research on postbiotics has uncovered many beneficial effects on hosts, including antioxidant activity, immunomodulatory effects, gut microbiota modulation, and enhancement of epithelial barrier function. Although these features resemble those of probiotics, the stability and safety of postbiotics make them an appealing alternative. In this review, we provide a comprehensive summary of the latest research on postbiotics, emphasizing their positive impacts on both human and animal health. As our understanding of the influence of postbiotics on living organisms continues to grow, their application in clinical and nutritional settings, as well as animal husbandry, is expected to expand. Moreover, by substituting postbiotics for antibiotics, we can promote health and productivity while minimizing adverse effects. This alternative approach holds immense potential for improving health outcomes and revolutionizing the food and animal products industries.

Lactobacilli and Klebsiella: Two Opposites in the Fight for Human Health

The problem of antibiotic resistance is currently very acute. Numerous research and development of new antibacterial drugs are being carried out that could help cope with various infectious agents. One of the promising directions for the search for new antibacterial drugs is the search among the probiotic strains present in the human gastrointestinal tract. This review is devoted to characteristics of one of these probiotic strains that have been studied to date: Limosilactobacillus reuteri. The review discusses its properties, synthesis of various compounds, as well as role of this strain in modulating various systems of the human body. The review also examines key characteristics of one of the most harmful among the currently known pathogenic organisms, Klebsiella, which is significantly resistant to antibiotics existing in medical practice, and also poses a great threat of nosocomial infections. Discussion of characteristics of the two strains, which have opposite effects on human health, may help in creation of new effective antibacterial drugs without significant side effects.

Study of the effect of Lactobacillus crispatus FSCDJY67L3 on Helicobacter Pylori eradication: a double-blind randomized controlled clinical trial

Helicobacter pylori (H. pylori) is a gram-negative bacterium exhibiting high pathogenicity. Traditional antibiotic treatments are considered ineffective as the H. pylori resistance has increased. Recently, a quadruple therapy strategy of probiotics and antibiotics to eliminate H. pylori was proposed. Probiotics play a therapeutic role as supplements in this process. The present research screened a probiotic strain (Lactobacillus crispatus FSCDJY67L3) that co-aggregates strongly with H. pylori. L. crispatus FSCDJY67L3 was demonstrated to significantly reduce H. pylori load (14C breath test) in clinical trials with H. pylori-positive patients. The Gastrointestinal Symptom Rating Scale (GSRS) score decreased, indicating improvement in the gastrointestinal discomfort of patients. Furthermore, L. crispatus FSCDJY67L3 showed no change in the structure of the intestinal flora of patients. Routine blood indices and blood biochemical indices related to liver and kidney function were also not affected in the patients. Therefore, L. crispatus FSCDJY67L3 may be used clinically as a supplement for the treatment of H. pylori.

Clinical Trial Registration

https://www.chictr.org.cn/, Chinese Clinical Trial Registry (ChiCTR2100053710).

Lactobacillus reuteri in digestive system diseases: focus on clinical trials and mechanisms

Objectives

Digestive system diseases have evolved into a growing global burden without sufficient therapeutic measures. Lactobacillus reuteri (L. reuteri) is considered as a new potential economical therapy for its probiotic effects in the gastrointestinal system. We have provided an overview of the researches supporting various L. reuteri strains' application in treating common digestive system diseases, including infantile colic, diarrhea, constipation, functional abdominal pain, Helicobacter pylori infection, inflammatory bowel disease, diverticulitis, colorectal cancer and liver diseases.

Methods

The summarized literature in this review was derived from databases including PubMed, Web of Science, and Google Scholar.

Results

The therapeutic effects of L. reuteri in digestive system diseases may depend on various direct and indirect mechanisms, including metabolite production as well as modulation of the intestinal microbiome, preservation of the gut barrier function, and regulation of the host immune system. These actions are largely strain-specific and depend on the activation or inhibition of various certain signal pathways. It is well evidenced that L. reuteri can be effective both as a prophylactic measure and as a preferred therapy for infantile colic, and it can also be recommended as an adjuvant strategy to diarrhea, constipation, Helicobacter pylori infection in therapeutic settings. While preclinical studies have shown the probiotic potential of L. reuteri in the management of functional abdominal pain, inflammatory bowel disease, diverticulitis, colorectal cancer and liver diseases, its application in these disease settings still needs further study.

Conclusion

This review focuses on the probiotic effects of L. reuteri on gut homeostasis via certain signaling pathways, and emphasizes the importance of these probiotics as a prospective treatment against several digestive system diseases.

Probiotics and autoprobiotics for treatment of Helicobacter pylori infection

The article discusses various approaches for probiotic treatment of Helicobacter pylori (H. pylori) infection: Probiotics as an adjuvant treatment in the standard eradication therapy; probiotic strains as a monotherapy; and autoprobiotics as a monotherapy. Autoprobiotics refer to indigenous bifidobacteria, lactobacilli, or enterococci isolated from a specific individual, intended to restore his/her microbiota and improve his/her health. The potential mechanisms of probiotic action against H. pylori include correction of the gut microbiota, immunological effects (enhancement of humoral and cellular immunity, and reduction of oxidative stress), direct antagonistic effects against H. pylori (such as colonization resistance and bacteriocin synthesis), and stimulation of local immunological protection (strengthening of the mucous protective barrier and reduction of gastric mucosa inflammation). The incorporation of probiotics into comprehensive eradication therapy shows promise in optimizing the treatment of H. pylori infection. Probiotics can enhance the eradication rates of H. pylori, reduce the occurrence and severity of side effects, and improve patient compliance. Probiotic or autoprobiotic monotherapy can be considered as an alternative treatment approach in cases of allergic reactions and insufficient effectiveness of antibiotics. We recommend including probiotics as adjunctive medications in anti-H. pylori regimens. However, further randomized multicenter studies are necessary to investigate the effects of probiotics and autoprobiotics against H. pylori, in order to gain a better understanding of their mechanisms of action.

Heat-Killed Bifidobacterium bifidum B1628 May Alleviate Dextran Sulfate Sodium-Induced Colitis in Mice, and the Anti-Inflammatory Effect Is Associated with Gut Microbiota Modulation

Inflammatory bowel disease (IBD) is a chronic inflammatory disease associated with gut dysbiosis. This study aimed to investigate the effects of heat-killed Bifidobacterium bifidum B1628 (HB1628) in dextran sulfate sodium (DSS)-induced colitis in mice. The following three mouse groups were included (n = eight per group): NC (normal control), DSS (colitis), and HB1628 (colitis and postbiotic). The mice in the DSS group showed significant weight loss and histological damage, developed bloody diarrhea, scored high in the disease activity index (DAI), and exhibited increases in pro-inflammatory cytokines (interleukin [IL]-1β, IL-6, and tumor necrosis factor [TNF]-α) and decreases in an anti-inflammatory cytokine (IL-13) in the serum. These changes were accompanied by gut microbiota modulation in colitis mice (decreases in Rikenellaceae and Eubacterium; increases in Peptostreptococcaceae, Bacteroides vulgatus, and Parasutterella excrementihominis). The HB1628 group had lower DAIs, histology scores, and serum levels of pro-inflammatory cytokines (IL-1β and TNF-α), but higher levels of an anti-inflammatory cytokine (IL-13), compared with the DSS group, suggesting a less severe inflammatory state after the HB1628 intervention. Additionally, HB1628 improved DSS-induced gut dysbiosis, which is evidenced by increases in intestinal beneficial bacteria, such as Lactobacillus, and decreases in known unfavorable taxa in IBD, e.g., Porphyromonadaceae, Subdoligranulum, Lachnospiraceae bacterium 3_1_46FAA, and Alistipes indistinctus. Functional metagenomics revealed three significantly enriched metabolic pathways in the HB1628 group (namely, the aerobic respiration I [cytochrome c] pathway and the superpathways of L-phenylalanine biosynthesis and L-tryptophan biosynthesis, respectively). In conclusion, our results showed that HB1628 effectively improved the inflammation state and tissue damage in DSS-induced colitis mice, and the symptom relief effect was accompanied by obvious gut microbiota remodulation.

Current and future perspectives for Helicobacter pylori treatment and management: From antibiotics to probiotics

Helicobacter pylori (H. pylori) is a Gram-negative anaerobic bacterium that colonizes the human stomach and is the leading cause of gastric diseases such as chronic gastritis and peptic ulcers, as well as the most definite and controllable risk factor for the development of gastric cancer. Currently, the regimen for H. pylori eradication has changed from triple to quadruple, the course of treatment has been extended, and the type and dose of antibiotics have been adjusted, with limited improvement in efficacy but gradually increasing side effects and repeated treatment failures in an increasing number of patients. In recent years, probiotics have become one of the most important tools for supporting intestinal health and immunity. Numerous in vitro studies, animal studies, and clinical observations have demonstrated that probiotics have the advantage of reducing side effects and increasing eradication rates in adjuvant anti-H. pylori therapy and are a valuable supplement to conventional therapy. However, many different types of probiotics are used as adjuncts against H. pylori, in various combinations, with different doses and timing, and the quality of clinical studies varies, making it difficult to standardize the results. In this paper, we focus on the risk, status, prevention, control, and treatment of H. pylori infection and review international consensus guidelines. We also summarize the available scientific evidence on using Limosilactobacillus reuteri (L. reuteri) as a critical probiotic for H. pylori treatment and discuss its clinical research and application from an evidence-based perspective.

Towards a knowledge graph for pre-/probiotics and microbiota-gut-brain axis diseases

Scientific publications present biological relationships but are structured for human reading, making it difficult to use this resource for semantic integration and querying. Existing databases, on the other hand, are well structured for automated analysis, but do not contain comprehensive biological knowledge. We devised an approach for constructing comprehensive knowledge graphs from these two types of resources and applied it to investigate relationships between pre-/probiotics and microbiota-gut-brain axis diseases. To this end, we created (i) a knowledge base, dubbed ppstatement, containing manually curated detailed annotations, and (ii) a knowledge base, called ppconcept, containing automatically annotated concepts. The resulting Pre-/Probiotics Knowledge Graph (PPKG) combines these two knowledge bases with three other public databases (i.e. MeSH, UMLS and SNOMED CT). To validate the performance of PPKG and to demonstrate the added value of integrating two knowledge bases, we created four biological query cases. The query cases demonstrate that we can retrieve co-occurring concepts of interest, and also that combining the two knowledge bases leads to more comprehensive query results than utilizing them separately. The PPKG enables users to pose research queries such as "which pre-/probiotics combinations may benefit depression?", potentially leading to novel biological insights.

The Influence of the Degree of Thermal Inactivation of Probiotic Lactic Acid Bacteria and Their Postbiotics on Aggregation and Adhesion Inhibition of Selected Pathogens

The study aimed to evaluate the effect of thermal inactivation of potentially probiotic lactic acid bacteria (LAB) strains isolated from food on their ability to compete with pathogenic microorganisms. Five strains of LAB, previously isolated from food and characterized, one commercial reference strain of Lactiplantibacillus plantarum 299v, and two indicator strains of Staphylococcus aureus 25923 and Listeriamonocytogenes 15313 were used in the study. The experiment consisted in applying a stress factor (high temperature: 80 °C, at a different time: 5, 15, and 30 min) to the tested LAB cells to investigate the in vitro properties such as hydrophobicity abilities (against p-xylene and n-hexadecane), auto-aggregation, co-aggregation with pathogens, and inhibition of pathogens adhesion to the porcine gastric mucin. The bacterial strains showed various hydrophobicity to p-xylene (36-73%) and n-hexadecane (11-25%). The affinity for solvents expanded with increasing thermal inactivation time. All LAB isolates were able to auto-aggregate (ranging from 17 to 49%). Bacterial strains subjected to 5 and 15 min of thermal inactivation had the highest auto-aggregation ability in comparison to viable and heat-killed cells for 30 min. The LAB strains co-aggregated with pathogens to different degrees; among them, the highest scores of co-aggregation were observed for L. monocytogenes, reaching 27% (with 15 min of heat-killed LAB cells). All LAB strains reduced the adherence of pathogenic bacteria in the competition test, moreover, heat-killed cells (especially 15 min inactivated) were more efficient than viable cells. The properties of selected LAB strains as moderately heat-stressed forms analyzed in the study increased the prevention of colonization and elimination of pathogenic bacteria in the in vitro model of gastrointestinal tract. The thermal inactivation process may therefore preserve and modifies some characteristics of bacterial cells.

Evaluation of the Potential Protective Effects of Lactobacillus Strains against Helicobacter pylori Infection: A Randomized, Double-Blinded, Placebo-Controlled Trial

BACKGROUND

The beneficial effects of probiotic supplementation standard antibiotic therapies for Helicobacter pylori infection have been verified, but the ability of probiotic monotherapy to eradicate H. pylori remains unclear.

AIM

To evaluate the accuracy and efficacy of specific Lactobacillus strains against H. pylori infection.

METHODS

Seventy-eight patients with H. pylori infection were treated with strain L. crispatus G14-5M (L. crispatus CCFM1118) or L. helveticus M2-09-R02-S146 (L. helveticus CCFM1121) or L. plantarum CCFM8610 at a dose of 2 g twice daily for one month. ¹⁴C-urea breath test, the gastrointestinal symptom rating scale, serum pepsinogen concentrations, and serum cytokine concentrations of patients were measured at baseline and end-of-trial to analyze the effect of the Lactobacillus strains in eradicating H. pylori infection and reducing gastrointestinal discomfort in patients. In addition, the composition and abundance of the intestinal microbiota of patients were also measured at end-of-trial.

RESULTS

The ¹⁴C-urea breath test value of the three Lactobacillus treatment groups had decreased significantly, and the eradication rate of H. pylori had increased by the end of the trial. In particular, the eradication rate in the G14-5M treatment group was significantly higher than the placebo group (70.59% vs. 15.38%, P=0.0039), indicating that one-month administration of the G14-5M regimen was sufficient to eradicate H. pylori infection. The ingestion of Lactobacillus strains also ameliorated the gastrointestinal symptom rating scale scores, and the serum interleukin-8 concentrations of H. pylori-infected patients appeared to modulate the gut microbiota of patients. However, none of the Lactobacillus strains had a significant effect on general blood physiological characteristics, serum tumor necrosis factor α concentrations, or serum pepsinogen concentrations in the patients.

CONCLUSION

Three Lactobacillus strains significantly alleviate the gastrointestinal discomfort and the gastric inflammatory response of H. pylori-infected patients. The activity of probiotics in eradicating H. pyloriinfection may be species/strain specific.

Investigating the effect of quadruple therapy with Saccharomyces boulardii or Lactobacillus reuteri strain (DSMZ 17648) supplements on eradication of Helicobacter pylori and treatments adverse effects: a double-blind placebo-controlled randomized clinical trial

Background

The goal of this study was to investigate the effects of treatment with Saccharomyces boulardii and Lactobacillus reuteri on the eradication of Helicobacter pylori and Adverse effects (AEs) of the treatment.

Results

This study was a double-blind, randomized, placebo-controlled trial. And, eradication of H. pylori was reported comparing quadruple therapy include of PPI (proton pomp inhibitor), bismuth subcitrate, clarithromycin, and amoxicillin versus quadruple therapy supplemented with S. boulardii and L. reuteri DSMZ 17648. For this aim, a total of 156 patients were included in the current study; and patients positive for H. pylori infection (n = 156) were randomly assigned to 3 groups: 52 patients (Group P) received conventional quadruple therapy plus L. reuteri, 52 patients (Group S) received conventional quadruple therapy plus S. boulardii daily, for 2 weeks, and 52 patients were in the control group (Group C). At the end of the treatment period, all the subjects continued to take proton pump inhibitor (PPI) alone for 14 days, and then, no medication was given for 2 weeks again. During follow-up, gastrointestinal symptoms were assessed using an evaluation scale (Glasgow dyspepsia questionnaire [GDQ]), and AEs were assessed at 7, 14, 21, and 28 days. As a result, all patients completed the treatment protocol in all groups by the end of the study. Additionally, eradication therapy was effective for 94.2% of subjects in Group S, 92.3% of subjects in Group P, and 86.5% of subjects in the control group, with no differences between treatment arms. In Group S, the chance of developing symptoms of nausea (OR = 2.74), diarrhea (OR = 3.01), headache (OR = 10.51), abdominal pain (OR = 3.21), and anxiety (OR = 3.58) was significantly lower than in the control group (p < 0.05).

Conclusion

S. boulardii could significantly reduce some AEs of H. pylori eradication therapy, but effectiveness of Lactobacillus reuteri on these cases was not significant. It is recommended to conduct the future research with larger sample size in order to investigate the effect.

Trial registration: IRCT20200106046021N1, this trial was registered on Jan 14, 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02187-z.

Probiotics in the treatment of Helicobacter pylori infection: reality and perspective

Helicobacter pylori (H. pylori) infection is one of the most common in the world today, associated with the development of acute or chronic inflammatory diseases of the gastroduodenal tract. In order to eradicate the pathogen, various antibacterial therapy regimens have been proposed, based on the use of several chemotherapeutic drugs and a proton pump inhibitor (PPI). However, recent studies indicate a decrease in antibiotic effectiveness due to both the growth rate of H. pylori resistance and side effects, often due to the development of dysbiosis. One of the promising areas of investigation is the treatment with probiotic therapy of helicobacteriosis. The use of probiotics, in the context of H. pylori infection, has two main reasons. The first is related to the use of certain probiotics to reduce the frequency of undesirable gastrointestinal consequences during H. pylori eradication therapy. The second is associated with the antagonistic effect of individual probiotics on H. pylori and the potentiation of the eradication effect. The purpose of this review was to summarize the latest data on the use of probiotics to enhance H. pylori eradication and to restore the gastrointestinal microbiota. Many unresolved questions, about the choice of the specific composition of the probiotic cocktail, dosage, duration of therapy, mechanisms of the antimicrobial action of probiotics, as well as possible negative consequences of such therapy, remain.

Effects of non-viable Lactobacillus reuteri combining with 14-day standard triple therapy on Helicobacter pylori eradication: A randomized double-blind placebo-controlled trial

BACKGROUND

Viable probiotics have shown effects on the eradication of Helicobacter pylori, but the role of non-viable probiotics in H. pylori eradication is unclear. This study aimed to evaluate the effects of non-viable Lactobacillus reuteri DSM17648 combining with 14-day standard triple therapy on H. pylori eradication.

MATERIALS AND METHODS

Two hundred treatment-naive H. pylori-positive adult patients were randomized equally to receive non-viable L. reuteri DSM17648 (LR group) or placebo for 4 weeks, with the latter 2 weeks treated together with triple therapy. The Gastrointestinal Symptom Rating Scale (GSRS) was completed before and after treatment. Stool samples were collected for 16S rRNA gene sequencing at week0, week2, and week8.

RESULTS

Eradication rates in the LR group and the placebo group were 81.8% and 83.7% in ITT analysis (p = 0.730), 86.2% and 87.2% in PP analysis (p = 0.830), respectively. After treatment, the mean GSRS score decreased significantly in the LR group as compared with the placebo group (1.9 ± 0.2 vs. 2.7 ± 0.3; p = 0.030). Significantly less patients in the LR group as compared with the placebo group reported abdominal distention (5.1% vs. 16.3%; p = 0.010) and diarrhea (11.1% vs. 23.5%; p = 0.022). The relative abundance of Proteobacteria phylum and Escherichia-Shigella genus in the placebo group was about 4.0-fold and 8.1-fold of that in the LR group at wk2, respectively. Significant changes of diversity and enhancements of Fusicatenibacter, Subdoligranulum, and Faecalibacterium were observed in the LR group compared with the placebo group.

CONCLUSIONS

Supplementation of non-viable L. reuteri DSM17648 with triple therapy did not improve the eradication rate of H. pylori, but it helped to build up a beneficial microbial profile and reduced the frequencies of abdominal distention, diarrhea, and the GSRS score.

Limosilactobacillus reuteri Strains as Adjuvants in the Management of Helicobacter pylori Infection

Helicobacter pylori (HP) is a Gram-negative bacterium which finds its suitable habitat in the stomach. The infection affects about half of the global population with high variability in prevalence among regions and for age. HP is the main causative agent of chronic active gastritis, peptic and duodenal ulcers, and may be the primary cause of gastric cancer or MALT lymphoma. Due to the high rate of failure of eradication therapy in various countries and the increase in antibiotic resistance reported in the literature, there is an ever wider need to seek alternative therapeutic treatments. Probiotics seem to be a promising solution. In particular, the Limosilactobacillus reuteri (L. reuteri) species is a Gram-positive bacterium and is commonly found in the microbiota of mammals. L. reuteri is able to survive the gastric acid environment and bile and to colonize the gastric mucosa. This species is able to inhibit the growth of several pathogenic bacteria through different mechanisms, keeping the homeostasis of the microbiota. In particular, it is able to secrete reuterin and reutericycline, substances that exhibit antimicrobial properties, among other molecules. Through the secretion of these and the formation of the biofilm, it has been found to strongly inhibit the growth of HP and, at higher concentrations, to kill it. Moreover, it reduces the expression of HP virulence factors. In clinical trials, L. reuteri has been shown to decrease HP load when used as a single treatment, but has not achieved statistical significance in curing infected patients. As an adjuvant of standard regimens with antibiotics and pump inhibitors, L. reuteri can be used not only to improve cure rates, but especially to decrease gastrointestinal symptoms, which are a common cause of lack of compliance and interruption of therapy, leading to new antibiotic resistance.

Paraprobiotics: A New Perspective for Functional Foods and Nutraceuticals

Probiotics are live microorganisms that confer health benefits on the host. However, in recent years, several concerns on their use have been raised. In particular, industrial processing and storage of probiotic products are still technological challenges as these could severely impair cell viability. On the other hand, safety of live microorganisms should be taken into account, especially when administered to vulnerable people, such as the elderly and immunodeficient individuals. These drawbacks have enhanced the interest toward new products based on non-viable probiotics such as paraprobiotics and postbiotics. In particular, paraprobiotics, defined as "inactivated microbial cells (non-viable) that confer a health benefit to the consumer," hold the ability to regulate the adaptive and innate immune systems, exhibit anti-inflammatory, antiproliferative and antioxidant properties and exert antagonistic effect against pathogens. Moreover, paraprobiotics can exhibit enhanced safety, assure technological and practical benefits and can also be used in products suitable for people with weak immunity and the elderly. These features offer an important opportunity to prompt the market with novel functional foods or nutraceuticals that are safer and more stable. This review provides an overview of central issues on paraprobiotics and highlights the urgent need for further studies aimed at assessing safety and efficacy of these products and their mechanisms of action in order to support decisions of regulatory authorities. Finally, a definition is proposed that unambiguously distinguishes paraprobiotics from postbiotics.

Paraprobiotics and Postbiotics of Probiotic Lactobacilli, Their Positive Effects on the Host and Action Mechanisms: A Review

Lactobacilli comprise an important group of probiotics for both human and animals. The emerging concern regarding safety problems associated with live microbial cells is enhancing the interest in using cell components and metabolites derived from probiotic strains. Here, we define cell structural components and metabolites of probiotic bacteria as paraprobiotics and postbiotics, respectively. Paraprobiotics and postbiotics produced from Lactobacilli consist of a wide range of molecules including peptidoglycans, surface proteins, cell wall polysaccharides, secreted proteins, bacteriocins, and organic acids, which mediate positive effect on the host, such as immunomodulatory, anti-tumor, antimicrobial, and barrier-preservation effects. In this review, we systematically summarize the paraprobiotics and postbiotics derived from Lactobacilli and their beneficial functions. We also discuss the mechanisms underlying their beneficial effects on the host, and their interaction with the host cells. This review may boost our understanding on the benefits and molecular mechanisms associated with paraprobiotics and probiotics from Lactobacilli, which may promote their applications in humans and animals.

Postbiotics and paraprobiotics: From concepts to applications

In recent years, new probiotic-related concepts such as postbiotics and paraprobiotics have been used to describe non-viable microorganisms or bacterial-free extracts that may provide benefits to the host by offering bioactivities additional to probiotics. However, several aspects related to these postbiotics and paraprobiotics bioactivities remain unexplored or are poorly understood. Therefore, the aim of this work is to provide an overview of the general aspects and emerging trends of postbiotics and paraprobiotics, such as conceptualization of terms, production, characterization, bioactivities, health-promoting effects, bioengineering approaches, and applications. In vitro and in vivo studies have demonstrated that some postbiotics and paraprobiotics exhibit bioactivities such as anti-inflammatory, immunomodulatory, anti-proliferative, antioxidant, and antimicrobial. These bioactivities could be involved in health-promoting effects observed in human and clinical trials, but despite the scientific evidence available, the mechanisms of action and the signaling pathways involved have not been fully elucidated. Nevertheless, paraprobiotics and postbiotics possess valuable potential for the development of biotechnological products with functional ingredients for the nutraceutical industry.

Lactobacillus reuteri versus triple therapy for the eradication of Helicobacter pylori in functional dyspepsia

Background and aim

The eradication of H. pylori infection using PPI associated with different combinations of two or three antibiotics entails high risks of side effects and non- adherence. Therefore probiotics have been proposed for H. pylori eradication.We tested the efficacy of Lactobacillus reuteri plus Pantoprazole compared to a triple regimen based on Pantoprazole plus Amoxicillin plus Clarithromycin in patients with H. pylori infection and functional dyspepsia.

Methods

In a prospective design, 46 patients (M: 13, F: 33, mean age 48.80 ± 13.82 years) fulfilled the following inclusion criteria: age at least 18, documented informed consent, positive H. pylori finding by histology, no morphological changes of the gastric mucosa at upper gastrointestinal endoscopy and complaints of functional dyspepsia according to the Rome III criteria. Exclusion criteria were: presence of any other chronic organic diseases that required drug treatment, use of antibiotics, PPIs or H2 antagonists in the previous 3 months; pregnancy or lactation. Patients were randomly divided into two equal groups (23 patients each group). One group received the standard therapy in our area: Pantoprazole 40 mg bid for 30 days associated with Amoxicillin 2×1000 mg/day and Clarithromycin 500 mg bid for 14 days. The other group received Pantoprazole 40 mg/day plus L. reuteri DSMZ 17648 twice a day for 8 weeks. Post-treatment eradication was tested by H. pylori antigen stool assay at 30 days after therapy.

Results

The group on L. reuteri plus Pantoprazole presented 65.22% eradication rate compared to 73.91% cure rate in the group that received the Pantoprazole and Amoxicillin and Clarithromycin therapy, with no statistically significant difference in eradication rate between the two groups (p=0.75). The total adherence was good and eradication of H. pylori was associated with improvement of dyspeptic symptoms for both eradication regimens.

Conclusion

L. reuteri is a good alternative for patients with chronic dyspepsia for the eradication of H. pylori infection. Its efficacy is similar to the triple therapy.

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).

Role of Lactobacillus reuteri in Human Health and Diseases

Lactobacillus reuteri (L. reuteri) is a well-studied probiotic bacterium that can colonize a large number of mammals. In humans, L. reuteri is found in different body sites, including the gastrointestinal tract, urinary tract, skin, and breast milk. The abundance of L. reuteri varies among different individuals. Several beneficial effects of L. reuteri have been noted. First, L. reuteri can produce antimicrobial molecules, such as organic acids, ethanol, and reuterin. Due to its antimicrobial activity, L. reuteri is able to inhibit the colonization of pathogenic microbes and remodel the commensal microbiota composition in the host. Second, L. reuteri can benefit the host immune system. For instance, some L. reuteri strains can reduce the production of pro-inflammatory cytokines while promoting regulatory T cell development and function. Third, bearing the ability to strengthen the intestinal barrier, the colonization of L. reuteri may decrease the microbial translocation from the gut lumen to the tissues. Microbial translocation across the intestinal epithelium has been hypothesized as an initiator of inflammation. Therefore, inflammatory diseases, including those located in the gut as well as in remote tissues, may be ameliorated by increasing the colonization of L. reuteri. Notably, the decrease in the abundance of L. reuteri in humans in the past decades is correlated with an increase in the incidences of inflammatory diseases over the same period of time. Direct supplementation or prebiotic modulation of L. reuteri may be an attractive preventive and/or therapeutic avenue against inflammatory diseases.

Microbial lysate upregulates host oxytocin

Neuropeptide hormone oxytocin has roles in social bonding, energy metabolism, and wound healing contributing to good physical, mental and social health. It was previously shown that feeding of a human commensal microbe Lactobacillus reuteri (L. reuteri) is sufficient to up-regulate endogenous oxytocin levels and improve wound healing capacity in mice. Here we show that oral L. reuteri-induced skin wound repair benefits extend to human subjects. Further, dietary supplementation with a sterile lysate of this microbe alone is sufficient to boost systemic oxytocin levels and improve wound repair capacity. Oxytocin-producing cells were found to be increased in the caudal paraventricular nucleus [PVN] of the hypothalamus after feeding of a sterile lysed preparation of L. reuteri, coincident with lowered blood levels of stress hormone corticosterone and more rapid epidermal closure, in mouse models. We conclude that microbe viability is not essential for regulating host oxytocin levels. The results suggest that a peptide or metabolite produced by bacteria may modulate host oxytocin secretion for potential public or personalized health goals.

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.

Probiotics in Helicobacter pylori-induced peptic ulcer disease

The ideal treatment regimen for the eradication Helicobacter pylori infection has yet to be identified. Probiotics, particularly Lactobacillus, Bifidobacterium and Saccharomyces, have been suggested as adjuncts to antibiotics for the treatment of H. pylori. There is in vitro evidence that probiotics dampen the Th1 response triggered by H. pylori, attenuate H. pylori associated hypochlorhydria and secrete bacteriocidal metabolites. Probiotics interact with the innate host immune system through adherence to the gastric epithelium and secretion of bacterial adhesins. In prospective human studies, probiotic monotherapy effectively decrease H. pylori density (expired (13)CO2) by 2.0%-64.0%. Probiotic monotherapy has also been shown to eradicate H. pylori in up to 32.5%, although subsequent recrudescence is likely. Eleven meta-analyses have evaluated the efficacy of probiotics as adjuvants to antibiotics for the eradication of H. pylori. The addition of a probiotic increased treatment efficacy, OR 1.12-2.07. This benefit is probably strain-specific and may only be significant with relatively ineffective antibiotic regimens. The pooled prevalence of adverse effects was 12.9%-31.5% among subjects receiving adjuvant probiotics, compared with 24.3%-45.9% among controls. Diarrhea in particular was significantly reduced in subjects receiving adjuvant probiotics, compared with controls (OR 0.16-0.47). A reduction in adverse events other than diarrhea is variable. Despite the apparent benefit on efficacy and side effects conferred by probiotics, the optimal probiotic species, dose and treatment duration has yet to be determined. Further studies are needed to identify the probiotic, antibiotic and patient factors which might predict benefit from probiotic supplementation.

Saccharomyces Boulardii in Helicobacter Pylori Eradication in Children: A Randomized Trial From Iran

Background:

Helicobacter pylori infects around 50% of the human population and is asymptomatic in 70% of the cases. H. pylori eradication in childhood will not only result in peptic symptoms relief, but will also prevent late-term complications such as cancer. Today, probiotics are being increasingly studied in the treatment of gastrointestinal infections as an alternative or complement to antibiotics.

Objectives:

In this study we aimed to assess the effect of S. boulardii supplementation on H. pylori eradication among children in our region.

Patients and Methods:

In this randomized double-blind placebo-controlled clinical trial 28 asymptomatic primary school children with a positive H. pylori stool antigen (HpSA) exam were randomly allocated into the study group, receiving Saccharomyces boulardii, and the control group receiving placebo capsules matched by shape and size, for one month. The children were followed up weekly and were reinvestigated four to eight weeks after accomplished treatment by HpSA testing. The significance level was set at P < 0.05.

Results:

24 children completed the study. The mean HpSA reduced from 0.40 ± 0.32 to 0.21 ± 0.27 in the study group, indicating a significant difference (P = 0.005). However, such difference was not observed in the control group (P = 0.89). Moreover, the HpSA titer showed a 0.019 ± 0.19 decrease in the study group whereas the same value was 0.0048 ± 0.12 for the controls, again stating a significant difference (P = 0.01).

Conclusions:

Saccharomyces boulardii has a positive effect on reducing the colonization of H. pylori in the human gastrointestinal system but is not capable of its eradication when used as single therapy.

Saccharomyces Boulardii in Helicobacter Pylori Eradication in Children: A Randomized Trial From Iran

BACKGROUND

Helicobacter pylori infects around 50% of the human population and is asymptomatic in 70% of the cases. H. pylori eradication in childhood will not only result in peptic symptoms relief, but will also prevent late-term complications such as cancer. Today, probiotics are being increasingly studied in the treatment of gastrointestinal infections as an alternative or complement to antibiotics.

OBJECTIVES

In this study we aimed to assess the effect of S. boulardii supplementation on H. pylori eradication among children in our region.

PATIENTS AND METHODS

In this randomized double-blind placebo-controlled clinical trial 28 asymptomatic primary school children with a positive H. pylori stool antigen (HpSA) exam were randomly allocated into the study group, receiving Saccharomyces boulardii, and the control group receiving placebo capsules matched by shape and size, for one month. The children were followed up weekly and were reinvestigated four to eight weeks after accomplished treatment by HpSA testing. The significance level was set at P < 0.05.

RESULTS

24 children completed the study. The mean HpSA reduced from 0.40 ± 0.32 to 0.21 ± 0.27 in the study group, indicating a significant difference (P = 0.005). However, such difference was not observed in the control group (P = 0.89). Moreover, the HpSA titer showed a 0.019 ± 0.19 decrease in the study group whereas the same value was 0.0048 ± 0.12 for the controls, again stating a significant difference (P = 0.01).

CONCLUSIONS

Saccharomyces boulardii has a positive effect on reducing the colonization of H. pylori in the human gastrointestinal system but is not capable of its eradication when used as single therapy.

Significant Reduction in Helicobacter pylori Load in Humans with Non-viable Lactobacillus reuteri DSM17648: A Pilot Study

Reducing the amount of Helicobacter pylori in the stomach by selective bacterial-bacterial cell interaction was sought as an effective and novel method for combating the stomach pathogen. Lactobacillus reuteri DSM17648 was identified as a highly specific binding antagonist to H. pylori among more than 700 wild-type strains of Lactobacillus species. Applying a stringent screening procedure, the strain DSM17648 was identified as selective binder to H. pylori cells under in vivo gastric conditions. The strain DSM17648 co-aggregates the pathogen in vivo and in vitro. The specific co-aggregation occurs between Lact. reuteri DSM17648 and different H. pylori strains and serotypes, as well as H. heilmannii, but not with Campylobacter jejuni or other commensal oral and intestinal bacteria. Lact. reuteri DSM17648 was shown in a proof-of-concept single-blinded, randomized, placebo-controlled pilot study to significantly reduce the load of H. pylori in healthy yet infected adults. Reducing the amount of H. pylori in the stomach by selective bacterial-bacterial cell interaction might be an effective and novel method for combating the stomach pathogen. Lact. reuteri DSM17648 might prove useful as an adhesion blocker in antibiotic-free H. pylori therapies.

Study and use of the probiotic Lactobacillus reuteri in pigs: a review

Probiotics are living microorganisms that provide a wide variety of health benefits to the host when ingested in adequate amounts. The bacterial strains most frequently used as probiotic agents are lactic acid bacteria, such as Lactobacillus reuteri, which is one of the few endogenous Lactobacillus species found in the gastrointestinal tract of vertebrates, including humans, rats, pigs and chickens. L. reuteri is one of the most well documented probiotic species and has been widely utilized as a probiotic in humans and animals for many years. Initially, L. reuteri was used in humans to reduce the incidence and the severity of diarrhea, prevent colic and necrotic enterocolitis, and maintain a functional mucosal barrier. As interest in alternatives to in-feed antibiotics has grown in recent years, some evidence has emerged that probiotics may promote growth, improve the efficiency of feed utilization, prevent diarrhea, and regulate the immune system in pigs. In this review, the characteristics of L. reuteri are described, in order to update the evidence on the efficacy of using L. reuteri in pigs.

The effect of probiotics supplementation on Helicobacter pylori eradication rates and side effects during eradication therapy: a meta-analysis

Background

Previous meta-analyses reported that probiotics improve the effectiveness of Helicobacter pylori (H. pylori) eradication during antibiotic therapy, while results regarding a possible reduction of side effects remained inconclusive. Moreover, the effectiveness of different strains of probiotics has not been studied so far. It is further conceivable that probiotics will produce additional effects only if antibiotics are relatively ineffective.

Methods

This meta-analysis includes eligible randomized controlled trials examining effects of probiotics supplementation on eradication rates (ER) and side effects, published up to May 2014. Sub-group analysis was performed to compare different probiotic strains and antibiotic therapies with different effectiveness in controls (ER <80% vs.>80%). Publication bias was assessed with funnel plots and Harbord's test. The quality of the trials was assessed with the Cochrane risk of bias tool.

Results

Thirty-three RCTs involving a total of 4459 patients met the inclusion criteria in case of eradication rates of which 20 assessed total side effects in addition. Overall, the pooled eradication rate in probiotics supplementation groups was significantly higher than in controls (ITT analysis: RR 1.122, 95% CI 1.086–1.159, PP analysis: RR 1.114, 95% CI 1.070–1.159). Sub group-analysis could, however, confirm this finding only for four individual strains (Lactobacillus acidophilus, Lactobacillus casei DN-114001, Lactobacillus gasseri, and Bifidobacterium infantis 2036) and for relatively ineffective antibiotic therapies. There was a significant difference between groups in the overall incidence of side effects (RR 0.735, 95% CI 0.598–0.902). This result was, however, only confirmed for non-blinded trials.

Conclusions

The pooled data suggest that supplementation with specific strains of probiotics compared with eradication therapy may be considered an option for increasing eradication rates, particularly when antibiotic therapies are relatively ineffective. The impact on side effects remains unclear and more high quality trials on specific probiotic strains and side effects are thus needed.

The overarching influence of the gut microbiome on end-organ function: the role of live probiotic cultures

At the time of birth, humans experience an induced pro-inflammatory beneficial event. The mediators of this encouraged activity, is a fleet of bacteria that assault all mucosal surfaces as well as the skin. Thus initiating effects that eventually provide the infant with immune tissue maturation. These effects occur beneath an emergent immune system surveillance and antigenic tolerance capability radar. Over time, continuous and regulated interactions with environmental as well as commensal microbial, viral, and other antigens lead to an adapted and maintained symbiotic state of tolerance, especially in the gastrointestinal tract (GIT) the organ site of the largest microbial biomass. However, the perplexing and much debated surprise has been that all microbes need not be targeted for destruction. The advent of sophisticated genomic techniques has led to microbiome studies that have begun to clarify the critical and important biochemical activities that commensal bacteria provide to ensure continued GIT homeostasis. Until recently, the GIT and its associated micro-biometabolome was a neglected factor in chronic disease development and end organ function. A systematic underestimation has been to undervalue the contribution of a persistent GIT dysbiotic (a gut barrier associated abnormality) state. Dysbiosis provides a plausible clue as to the origin of systemic metabolic disorders encountered in clinical practice that may explain the epidemic of chronic diseases. Here we further build a hypothesis that posits the role that subtle adverse responses by the GIT microbiome may have in chronic diseases. Environmentally/nutritionally/and gut derived triggers can maintain microbiome perturbations that drive an abnormal overload of dysbiosis. Live probiotic cultures with specific metabolic properties may assist the GIT microbiota and reduce the local metabolic dysfunctions. As such the effect may translate to a useful clinical treatment approach for patients diagnosed with a metabolic disease for end organs such as the kidney and liver. A profile emerges that shows that bacteria are diverse, abundant, and ubiquitous and have significantly influenced the evolution of the eukaryotic cell.

Review article: bacteria and pathogenesis of disease in the upper gastrointestinal tract--beyond the era of Helicobacter pylori

BACKGROUND

Study of the upper gastrointestinal microbiome has shown that other bacteria besides Helicobacter pylori flourish despite the hostile environment. Whilst H. pylori is the most studied bacteria in this region with a defined role in inflammation and neoplasia, it is apparent that other bacteria may contribute to UGI disease.

AIM

To review current knowledge of bacteria inhabiting the oesophagus, stomach and duodenum.

METHODS

Published studies on the upper gastrointestinal microbiome (extracted from PubMed during the last 20 years).

RESULTS

The stomach is a hostile environment for bacteria; however, recent studies categorising the microbiota have shown surprising results. Helicobacter pylori has been intensively studied since 1984 and recent sequencing analysis of other gastric microbiota shows that H. pylori is not alone. Composition can be influenced by acid suppression, gastritis and abundance of H. pylori. Eradication of H. pylori, whilst decreasing gastric cancer is associated with an increase in asthma, reflux and obesity. A future approach may be to selectively eradicate bacteria which predispose to inflammation and cancer as opposed to a comprehensive knockout policy. In the oesophagus, viridans streptococci are the most common bacteria influenced by both oral and gastric bacteria. Oesophagitis and Barrett's oesophagus are characterised by a significant decrease in Gram-positive bacteria and an increase in Gram-negative bacteria. An inverse association of H. pylori and oesophageal adenocarcinoma is described. The duodenal microbiome has been shown to influence small intestinal bacterial overgrowth, irritable bowel syndrome and coeliac disease. The numbers of bacteria recoverable by culture are variable in the stomach mucosa and gastric juice, typically 10(2) -10(4) colony-forming units (CFU)/g or mL and in the oesophagus, up to 10(4) bacteria per mm(2) mucosal surface. In the small bowel, in health, 10(3) CFU/mL are normal.

CONCLUSION

This review highlights current knowledge of upper gastrointestinal bacteria and associations with disease.