Effects of Lactobacillus gasseri OLL2716 on Helicobacter pylori-Associated Dyspepsia: A Multicenter Randomized Double-Blind Controlled Trial

Efficacy of Lactobacillus spp. Supplementation in Helicobacter pylori Eradication: A Systematic Meta-Analysis of Randomized Controlled Trials With Trial Sequential Analysis

BACKGROUND

Helicobacter pylori infection is a major global health concern and has been associated with a number of gastrointestinal disorders. Probiotics, especially Lactobacillus spp., have been suggested to have beneficial effect in managing H. pylori infection. This meta-analysis of randomized control trials (RCTs) aimed to evaluate the effect of Lactobacillus spp. supplementation on H. pylori eradication rates and associated side effects when combined with standard therapy.

MATERIALS AND METHODS

Relevant studies were retrieved from PubMed, Scopus, Google Scholar and the Cochrane Library. Comprehensive Meta-Analysis (CMA) Software 4.0 was used for all the statistical analyses. TSA 0.9.5.10 Beta software was used for the trial sequential analysis (TSA). GRADEpro GDT was used to assess the certainty of evidence.

RESULTS

An analysis of 26 selected studies showed that supplementing with Lactobacillus spp. significantly increased the rates of H. pylori eradication in per-protocol (PP) analysis (Overall risk ratio [RR] = 1.063, p = 0.000, 95% CI of -0.21 to 2.11; adults: RR = 1.050, p = 0.005, 95% CI = -0.55 to 2.03, children: RR = 1.223, p = 0.001, 95% CI = -13.35 to 4.55). In comparison to quadruple therapy, Lactobacillus spp. supplementation to triple therapy showed significant benefit (RR: 1.124; p = 0.000, 95% CI of -0.48 to 2.61). L. reuteri supplementation indicated better efficacy (RR: 1.049; p = 0.055, 95% CI of -0.56 to 3.26) than Lactobacillus GG (RR: 0.980; p = 0.595, 95% CI of -0.69 to 1.21). The 28-30 day (RR: 1.103; p = 0.003, 95% CI of -2.14 to 4.19) and 14-day supplementation periods (RR: 1.102; p = 0.003, 95% CI of -1.69 to 3.51) showed the most improvement. The analysis also revealed that Lactobacillus spp. significantly reduced gastrointestinal side effects: nausea/vomiting (RR: 0.566; p = 0.037, -3.11 to 1.45), diarrhea (RR: 0.324; p = 0.000, -5.46 to 0.48), and abdominal pain (RR: 0.438; p = 0.007, -5.65 to 4.22). The effect on bloating was non-significant (RR: 0.820; p = 0.498, -4.01 to 0.96). TSA graphs validated sufficient evidence for the conclusions.

CONCLUSION

Lactobacillus spp. significantly enhances H. pylori eradication rates and may reduce gastrointestinal side effects when used alongside standard therapy, offering a promising adjunctive treatment option. The evidence was supported by TSA and assessed using GRADEpro, indicating a high certainty of the findings.

The Beneficial Effects of Regular Intake of Lactobacillus paragasseri OLL2716 on Gastric Discomfort in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Study

We investigated the effects of Lactobacillus paragasseri OLL2716 on gastrointestinal symptoms in healthy adults with gastric complaints. In this randomized, double-blind, placebo-controlled trial, 174 healthy Japanese adults were randomly assigned to an OLL2716 or placebo group, and each group consumed 85 g of yogurt containing L. paragasseri OLL2716 or placebo yogurt daily for 12 weeks. The primary endpoint was the change in gastric symptoms from baseline as per the participants' questionnaires at 6 and 12 weeks. The secondary endpoints were changes from baseline in the short-form Nepean Dyspepsia Index (SF-NDI), the Gastrointestinal Symptom Rating Scale (GSRS), and the Council on Nutrition Appetite Questionnaire-Japanese (CNAQ-J) scores at 6 and 12 weeks. The primary endpoint data showed that the changes in "epigastric pain" at 6 and 12 weeks were significantly decreased in the OLL2716 group compared with those in the placebo group. Additionally, the changes in "epigastric pain syndrome-like symptoms" were significantly decreased in the OLL2716 group compared with those in the placebo group at 6 weeks. The SF-NDI items that improved at 6 weeks were "irritable, tense, or frustrated", "enjoyment of eating or drinking", and "tension", which are sub-scales related to mental stress. The items "Over-all" in the GSRS and "feeling hungry" in the CNAQ-J significantly improved in the OLL2716 group compared with the placebo group at 12 weeks. The results suggest that regular intake of L. paragasseri OLL2716 may improve both gastric discomfort and mental stress in healthy adults with gastric complaints, such as postprandial fullness or early satiety.

Effects of Latilactobacillus sakei LZ217 on Gastric Mucosal Colonization, Metabolic Interference, and Urease Expression in Helicobacter pylori Infection

Emerging evidence suggests differential antagonism of lactic acid-producing bacteria (LAB) to Helicobacter pylori, posing challenges to human health and food safety due to unclear mechanisms. This study assessed 21 LAB strains from various sources on H. pylori growth, urease activity, and coaggregation. Composite scoring revealed that Latilactobacillus sakei LZ217, derived from fresh milk, demonstrates strong inhibitory effects on both H. pylori growth and urease activity. L. sakei LZ217 significantly reduced H. pylori adherence of gastric cells in vitro, with inhibition ratios of 47.62%. Furthermore, in vivo results showed that L. sakei LZ217 alleviated H. pylori-induced gastric mucosa damage and inflammation in mice. Metabolomic exploration revealed metabolic perturbations in H. pylori induced by L. sakei LZ217, including reduced amino acid levels (e.g., isoleucine, leucine, glutamate, aspartate, and phenylalanine) and impaired carbohydrate and nucleotide synthesis, contributing to the suppression of ureA (28.30%), ureE (84.88%), and ureF (59.59%) expressions in H. pylori. This study underscores the efficacy of LAB against H. pylori and highlights metabolic pathways as promising targets for future interventions against H. pylori growth and colonization.

Effect of Lactobacillus gasseri BIO6369 and Lacticaseibacillus rhamnosus BIO5326 on Gastric Carcinogenesis Induced by Helicobacter pylori Infection

BACKGROUND

Helicobacter pylori infection-associated gastric adenocarcinoma is influenced by various factors, including the digestive microbiota. Lactic acid bacteria role in digestive carcinogenesis has been discussed, and some Lactobacillaceae family species have been shown to act against H. pylori-induced inflammation and colonization. However, their effects on H. pylori-related carcinogenesis have not yet been studied. Lactobacillaceae family effects on the epithelial-to-mesenchymal transition (EMT), emergence of cells with cancer stem cell (CSC) properties and the pro-inflammatory response of gastric epithelial cells to H. pylori infection were investigated.

MATERIALS AND METHODS

A co-culture model of AGS gastric epithelial cells infected with a carcinogenic strain of H. pylori associated with 18 different probiotic strains candidates were used. Different EMT indicators and CSC properties were studied, including quantification of the mesenchymal phenotype, tumorsphere formation, EMT marker expression, and tight junction evaluation with immunofluorescence microscopy. The effect of the strains on the pro-inflammatory response to H. pylori was also evaluated by quantifying interleukin-8 (IL-8) production using ELISA.

RESULTS

Among the strains tested, Lactobacillus gasseri BIO6369 and Lacticaseibacillus rhamnosus BIO5326 induced a 30.6% and 38.4% reduction in the mesenchymal phenotype, respectively, caused a significant decrease in Snail and Zeb1 EMT marker expression and prevented the loss of tight junctions induced by H. pylori infection. A separate co-culture with a Boyden chamber maintained the effects induced by the two strains. H. pylori-induced IL-8 production was also significantly reduced in the presence of L. gasseri BIO6369 and L. rhamnosus BIO5326.

CONCLUSION

Lactobacillus gasseri BIO6369 and L. rhamnosus BIO5326 strains decreased epithelial-to-mesenchymal transition and inflammation induced by H. pylori infection, suggesting that these species may have a protective effect against H. pylori-induced gastric carcinogenesis.

Beneficial Effect of Heat-Killed Lactic Acid Bacterium Lactobacillus johnsonii No. 1088 on Temporal Gastroesophageal Reflux-Related Symptoms in Healthy Volunteers: A Randomized, Placebo-Controlled, Double-Blind, Parallel-Group Study

A randomized, placebo-controlled, double-blind, parallel-group clinical study was conducted to examine the effects of ingesting a heat-killed lactic acid bacterium, Lactobacillus johnsonii No. 1088 (LJ88) on temporal gastroesophageal reflux-related symptoms in healthy volunteers. A total of 120 healthy Japanese volunteers of both sexes, aged between 21 and 63 years, whose Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease (FSSG) total score was 8 or greater, but who were not diagnosed with functional dyspepsia according to the Rome IV classification, were enrolled. They were randomly assigned to either the LJ88 or placebo group and instructed to ingest the test food (1 billion heat-killed LJ88 or placebo) once a day for six weeks. Gastroesophageal reflux-related symptoms were evaluated using FSSG scores as a primary endpoint. The Gastrointestinal Symptoms Rating Scale (GSRS), stomach state questionnaire, and serum gastrin concentration were used as secondary endpoints. In the FSSG evaluation, the heartburn score was significantly improved at 6 weeks in the LJ88 group compared to the placebo group. No severe adverse events related to the test food were observed. In conclusion, daily ingestion of heat-killed LJ88 improved temporal heartburn symptoms in non-diseased individuals.

The modulatory effect of Lactobacillus gasseri ATCC 33323 on autophagy induced by extracellular vesicles of Helicobacter pylori in gastric epithelial cells in vitro

Helicobacter pylori has been recognized as a true pathogen, which is associated with various gastroduodenal diseases, and gastric adenocarcinoma. The crosstalk between H. pylori virulence factors and host autophagy remains challenging. H. pylori can produce extracellular vesicles (EVs) that contribute to gastric inflammation and malignancy. Some probiotic strains have been documented to modulate cell autophagy process. This study was aimed to investigate the modulatory effect of cell-free supernatant (CFS) obtained from Lactobacillus gasseri ATCC 33323 on autophagy induced by H. pylori-derived EVs. EVs were isolated from two clinical H. pylori strains (BY-1 and OC824), and characterized using transmission electron microscopy (TEM) and dynamic light scattering (DLS). The viability of AGS cells was assessed after exposure to different concentrations of H. pylori EVs, and L. gasseri CFS. Based on MTT assay and Annexin V-FITC/PI staining, 50 μg/ml of H. pylori EVs and 10 % v/v of L. gasseri CFS were used for further cell treatment experiments. Autophagy was examined using acridin orange (AO) staining, RT-qPCR analysis for autophagy mediators (LC3B, ATG5, ATG12, ATG16L1, BECN1, MTOR, and NOD1), and western blotting for LC3B expression. H. pylori EVs were detected to range in size from 50 to 200 nm. EVs of both H. pylori strains and L. gasseri CFS showed no significant effect on cell viability as compared to untreated cells. H. pylori EVs promoted the development of acidic vesicular organelles and the expression of autophagy-related genes (LC3B, ATG5, ATG12, ATG16L1, BECN1, and NOD1), and decreased the expression of MTOR in AGS cells at 12 and 24 h time periods. In addition, the production of LC3B was increased following 12 h of treatment in AGS cells. In contrast, L. gasseri CFS effectively inhibited EVs-induced autophagy, as evidenced by reduced acidic vesicular organelle formation and modulation of autophagy markers. Our study indicated that L. gasseri CFS can effectively suppress H. pylori EV-induced autophagy in AGS cells. Further investigations are required to decipher the mechanism of action L. gasseri CFS and its metabolites on autophagy inhibition induced by H. pylori.

Characterization, mechanism and in vivo validation of Helicobacter pylori antagonism by probiotics screened from infants' feces and oral cavity

Helicobacter pylori (H. pylori) infection is a major cause of chronic gastritis, intestinal metaplasia, and gastric carcinoma. Antibiotics, the conventional regimen for eliminating H. pylori, cause severe bacterial resistance, gut dysbiosis and hepatic insufficiency. Here, fifty lactic acid bacteria (LAB) were initially screened out of 266 strains obtained from infants' feces and oral cavity. The antagonistic properties of these 50 strains against H. pylori were investigated. Based on eight metrics combined with principal component analysis, three LAB with probiotic function and excellent anti-H. pylori capacity were affirmed. Combining dynamics test, metabolite assays, adhesion assays, co-cultivation experiments, and SEM and TEM observations, LAB were found to antagonize H. pylori by causing coccoid conversion and intercellular adhesion. Furthermore, it was found that LAB antagonized H. pylori by four pathways, i.e., production of anti-H. pylori substances, inhibition of H. pylori colonization, enhancement of the gastric mucosal barrier, and anti-inflammatory effect. In addition, animal model experiments verified that the final screened superior strain L. salivarius NCUH062003 had anti-H. pylori activity in vivo. LAB also reduced IL-8 secretion, ultimately alleviating the inflammatory response of gastric mucosa. Whole genome sequencing (WGS) data showed that the NCUH062003 genome contained the secondary metabolite biosynthesis gene cluster T3PKS. Furthermore, NCUH062003 had a strong energy metabolism and substance transport capacity, and produced a small molecule heat stable peptide (SHSP, 4.1-6.5 kDa). Meanwhile, LAB proved to be safe through antibiotic susceptibility testing and CARD database comparisons.

Targeting the altered duodenal microenvironment in functional dyspepsia

Duodenal micro-inflammation and microbial dysregulation are increasingly recognized to play an important role in functional dyspepsia (FD) pathophysiology, previously regarded as a purely functional disorder. With current therapeutic options contested through insufficient efficacy or unfavorable adverse effects profiles, novel treatments directed to duodenal alterations could result in superior symptom control in at least a subset of patients. Indeed, recent advances in FD research provided evidence for anti-inflammatory therapies to relieve gastroduodenal symptoms by reducing duodenal eosinophils or mast cells. In addition, restoring microbial homeostasis by probiotics proved to be successful in FD. As the exact mechanisms by which these novel pharmacological approaches result in clinical benefit often remain to be elucidated, future research should focus on how immune activation and dysbiosis translate into typical FD symptomatology.

Microbiota in the stomach and application of probiotics to gastroduodenal diseases

The stomach is a hostile environment for most microbes because strong gastric acid kills indigenous microorganisms. Thus, the mass of indigenous microbes detected by traditional culturing method in a highly acidic stomach is reported to be very small. However, in a stomach with less acidity due to atrophic changes of the gastric mucosa, the number of live gastric microbiota dramatically increases and their composition changes. A probiotic is defined as a live microorganism that, when administered in adequate amounts, confers a health benefit on the host. The administration of probiotics to the stomach has thus far been considered impractical, mainly due to the strong acidity in the stomach. The identification of candidate probiotic strains with sufficient resistance to acidity and the ability to achieve close proximity to the gastric mucosa could enable the application of probiotics to the stomach. The utilization of probiotics alone for Helicobacter pylori (H. pylori) infection significantly improves gastric mucosal inflammation and decreases the density of H. pylori on the mucosa, although complete eradication of H. pylori has not yet been demonstrated. The use of probiotics in combination with antimicrobial agents significantly increases the H. pylori eradication rate, especially when the H. pylori strains are resistant to antimicrobial agents. While H. pylori has been considered the most important pathogenic bacterium for the development of gastric cancer, bacteria other than H. pylori are also suggested to be causative pathogens that promote the development of gastric cancer, even after the eradication of H. pylori. Increased non-H. pylori Gram-negative bacteria in the stomach with weak acidity accompanying atrophic gastritis may perpetuate gastric mucosal inflammation and accelerate carcinogenic progression, even after H. pylori eradication. Probiotics restore the acidity in this stomach environment and may therefore prevent the development of gastric cancer by termination of Gram-negative bacteria-induced inflammation. Functional dyspepsia (FD) is defined as the presence of symptoms that are thought to originate in the gastroduodenal region in the absence of any organic, systematic or metabolic diseases. Accumulating evidence has pointed out the duodenum as a target region underlying the pathophysiology of FD. A randomized placebo-controlled clinical trial using a probiotic strain (LG21) demonstrated a significant improving effect on major FD symptoms. One of the possible mechanisms of this effect is protection of the duodenal mucosa from injurious intestinal bacteria through the resolution of small intestinal bacterial over growth.

Role of the duodenal microbiota in functional dyspepsia

BACKGROUND

Functional dyspepsia (FD) is a common and debilitating gastrointestinal disorder attributed to altered gut-brain interactions. While the etiology of FD remains unknown, emerging research suggests the mechanisms are likely multifactorial and heterogenous among patient subgroups. Small bowel motor disturbances, visceral hypersensitivity, chronic microinflammation, and increased intestinal tract permeability have all been linked to the pathogenesis of FD. Recently, alterations to the gut microbiome have also been implicated to play an important role in the disease. Changes to the duodenal microbiota may either trigger or be a consequence of immune and neuronal disturbances observed in the disease, but the mechanisms of influence of small intestinal flora on gastrointestinal function and symptomatology are unknown.

PURPOSE

This review summarizes and synthesizes the literature on the link between the microbiota, low-grade inflammatory changes in the duodenum and FD. This review is not intended to provide a complete overview of FD or the small intestinal microbiota, but instead outline some of the key conceptual advances in understanding the interactions between altered gastrointestinal bacterial communities; dietary factors; host immune activation; and stimulation of the gut-brain axes in patients with FD versus controls. Current and emerging treatment approaches such as dietary interventions and antibiotic or probiotic use that have demonstrated symptom benefits for patients are reviewed, and their role in modulating the host-microbiota is discussed. Finally, suggested opportunities for diagnostic and therapeutic improvements for patients with this condition are presented.

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.

Relationship between Helicobacter pylori infection and gastrointestinal microecology

The prevalence of Helicobacter pylori (H. pylori) infection has exceeded 50% worldwide, and it is considered a high-risk factor for chronic gastritis, peptic ulcer, gastric adenocarcinoma, gastroesophageal reflux disease and functional dyspepsia. H. pylori drug resistance is a common problem worldwide. In recent years, the relationship between H. pylori infection and gastrointestinal microecology has received much attention. H. pylori infection changes the structure and composition of gastrointestinal microflora by regulating the gastrointestinal microecological environment, local pH value, cytokines and antimicrobial peptides, and immune response and then plays a crucial role in the occurrence and development of digestive system tumors, liver metabolism and extragastrointestinal diseases. The quadruple strategy of H. pylori eradication can also aggravate gastrointestinal microflora disorder. However, probiotics can reduce intestinal flora changes and imbalances through different mechanisms, thus enhancing the efficacy of H. pylori eradication therapy and reducing adverse reactions caused by eradication therapy. Therefore, this paper reviews the relationship between H. pylori infection and gastrointestinal microecology and its clinical application, providing a basis for clinical treatment.

Bi-Directionality of the Microbiota-Gut-Brain Axis in Patients With Functional Dyspepsia: Relevance of Psychotherapy and Probiotics

Functional dyspepsia is one of the most commonly diagnosed disorders of the gut-brain interaction worldwide. The precise pathogenesis of functional dyspepsia is complex and remains incompletely understood. Therefore, advances in the understanding of functional dyspepsia could change clinical practice. The aim of this review is to highlight the relevance of psychotherapy and probiotics in the context of the microbiota-gut-brain axis in the pathophysiology and especially in the treatment of functional dyspepsia. Therefore, studies which have been conducted to investigate the role of psychotherapy and probiotics in FD and the microbiota-gut-brain axis in the pathophysiology of functional dyspepsia were examined, and the outcomes of this research summarized. There might be a link between changes in the microbiome and functional dyspepsia. Even though, specific alterations in the microbiome that may be pathognomonic in functional dyspepsia remain unclear, the use of probiotics became a viable treatment option for patients with functional dyspepsia. Since mental illness also plays an important role in the pathophysiology of functional dyspepsia, psychotherapy is a useful treatment method, with additional study results indicating that psychotherapy may also shift the microbiome in a favorable direction. Moreover, other findings suggest that probiotics can be used not only to alleviate gastrointestinal symptoms in functional dyspepsia, but also to treat or even prevent mental disorders in these patients. In summary, in this review we highlight the bi-directionality of the microbiota-gut-brain axis in the pathophysiology of functional dyspepsia. Although there are multiple treatment approaches, the burden of disease in patients with functional dyspepsia is still enormous and a definitive therapy to cure this disease does not (yet) exist. Lastly, there is a lack of studies on the impact of dysbiosis, mental health and probiotics on pathophysiology and symptomatology in functional dyspepsia which should be investigated in future studies.

Evidence-based clinical practice guidelines for functional dyspepsia 2021

BACKGROUND

Functional dyspepsia (FD) is a disorder that presents with chronic dyspepsia, which is not only very common but also highly affects quality of life of the patients. In Japan, FD became a disease name for national insurance in 2013, and has been gradually recognized, though still not satisfactory. Following the revision policy of Japanese Society of Gastroenterology (JSGE), the first version of FD guideline was revised this time.

METHOD

Like previously, the guideline was created by the GRADE (grading of recommendations assessment, development and evaluation) system, but this time, the questions were classified to background questions (BQs, 24 already clarified issues), future research questions (FRQs, 9 issues cannot be addressed with insufficient evidence), and 7 clinical questions that are mainly associated with treatment.

RESULTS AND CONCLUSION

These revised guidelines have two major features. The first is the new position of endoscopy in the flow of FD diagnosis. While endoscopy was required to all cases for diagnosis of FD, the revised guidelines specify the necessity of endoscopy only in cases where organic disease is suspected. The second feature is that the drug treatment options have been changed to reflect the latest evidence. The first-line treatment includes gastric acid-secretion inhibitors, acetylcholinesterase (AChE) inhibitors (acotiamide, a prokinetic agent), and Japanese herbal medicine (rikkunshito). The second-line treatment includes anxiolytics /antidepressant, prokinetics other than acotiamide (dopamine receptor antagonists, 5-HT4 receptor agonists), and Japanese herbal medicines other than rikkunshito. The patients not responding to these treatment regimens are regarded as refractory FD.

Combined Signature of the Urinary Microbiome and Metabolome in Patients With Interstitial Cystitis

Interstitial cystitis (IC) is a clinical syndrome characterized by frequency, urgency, and bladder pain or pelvic pain; however, the underlying pathophysiological mechanisms and diagnostic markers are unknown. In this study, microbiome and metabolome analysis were used to explain the urine signatures of IC patients. Urine samples from 20 IC patients and 22 control groups were analyzed by using 16S rRNA sequence and liquid chromatography coupled with mass spectrometry. Four opportunistic pathogen genera, including Serratia, Brevibacterium, Porphyromonas, and Citrobacter, were significantly upregulated in IC group. The altered metabolite signatures of the metabolome may be related to sphingosine metabolism, amino acid metabolism, and fatty acid biosynthesis. Meanwhile, the associations were observed between different metabolites and microbiomes of IC. The present study suggests that the combined signatures of IC in urine microbiome and metabolome may become its prospective diagnostic markers.

Mechanisms of Food-Induced Symptom Induction and Dietary Management in Functional Dyspepsia

Functional dyspepsia (FD) is a common disorder of gut-brain interaction, characterised by upper gastrointestinal symptom profiles that differentiate FD from the irritable bowel syndrome (IBS), although the two conditions often co-exist. Despite food and eating being implicated in FD symptom induction, evidence-based guidance for dietetic management of FD is limited. The aim of this narrative review is to collate the possible mechanisms for eating-induced and food-related symptoms of FD for stratification of dietetic management. Specific carbohydrates, proteins and fats, or foods high in these macronutrients have all been reported as influencing FD symptom induction, with removal of 'trigger' foods or nutrients shown to alleviate symptoms. Food additives and natural food chemicals have also been implicated, but there is a lack of convincing evidence. Emerging evidence suggests the gastrointestinal microbiota is the primary interface between food and symptom induction in FD, and is therefore a research direction that warrants substantial attention. Objective markers of FD, along with more sensitive and specific dietary assessment tools will contribute to progressing towards evidence-based dietetic management of FD.

Evaluation of main functional dyspepsia symptoms after probiotic administration in patients receiving conventional pharmacological therapies

Objective

Postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS) are the two main forms of functional dyspepsia (FD). Probiotics are a promising therapy for FD, but current data remains heterogeneous. This work aims to evaluate a probiotic combination of Lacticaseibacillus rhamnosus LR04 (DSM 16605), Lactiplantibacillus pentosus LPS01 (DSM 21980), Lactiplantibacillus plantarum LP01 (LMG P-21021), and Lactobacillus delbrueckii subsp. delbruekii LDD01 (DMS 22106), alone or together with other pharmacological therapies, for clinical improvement of symptoms associated with FD.

Methods

Patients with FD were enrolled and divided into two groups: PDS and EPS. Probiotic alone or combined with prokinetics, antacids, or proton-pump-inhibitors were administered for 30 days. A progressive-score scale was used to evaluate symptoms in all patients at the beginning of the trial and at 15 days after the end of treatment.

Results

A cohort of 2676 patients were enrolled (1 357 with PDS; 1 319 with EPS). All patients showed significant improvements in dyspeptic symptoms following treatment. In patients with PDS, probiotic alone resulted in the lowest prevalence of symptoms following treatment, while patients with EPS showed no clear between-treatment differences.

Conclusions

Dyspeptic symptoms were reduced following treatment in all patients.

Effects of a Potential Probiotic Strain Lactobacillus gasseri ATCC 33323 on Helicobacter pylori-Induced Inflammatory Response and Gene Expression in Coinfected Gastric Epithelial Cells

In the present study, we aimed to investigate the modulatory effects of a potential probiotic bacterium Lactobacillus gasseri ATCC 33323 on Helicobacter pylori-induced inflammatory response and gene expression in human gastric adenocarcinoma (AGS) cell line. The gastric epithelial cells were coinfected with a collection of H. pylori clinical strains alone or in combination with L. gasseri at a multiplicity of infection (MOI) of 1:100 for each bacterium, and incubated for different time points of 3, 6, and 12 h. IL-8 secretion from coinfected AGS cells after incubation at each time point was measured by an enzyme-linked immunosorbent assay (ELISA). The mRNA expression of IL-8, Bcl-2, β-catenin, integrin α₅, and integrin β₁ genes was determined by quantitative RT-PCR amplification of total RNA extracted from coinfected epithelial cells. L. gasseri significantly (P < 0.05 and P < 0.01) decreased the production of IL-8 in AGS cells coinfected with H. pylori strains at 6 h post-infection. We also detected that L. gasseri significantly (P < 0.05) down-regulated the gene expression level of IL-8 in H. pylori-stimulated AGS cells after 6 and 12 h of coinfection. Similarly, L. gasseri caused a significant decrease (P < 0.05) in mRNA expression of Bcl-2, β-catenin, integrin α₅, and integrin β₁ genes in AGS cells at 3 and 6 h after infection with H. pylori strains as compared with non-infected control cells. In conclusion, our results demonstrated that L. gasseri ameliorates H. pylori-induced inflammation and could be developed as a supplementation to the current treatment regimens administrated against H. pylori infection.

Meta-analysis of the efficacy of probiotic-supplemented therapy on the eradication of H. pylori and incidence of therapy-associated side effects

Traditional therapies for Helicobacter pylori (H. pylori) infection remain hindered by the antibiotic resistance of the pathogen and the poor therapeutic compliance of patients. To address these issues, probiotics have been added as an adjunctive therapy. This meta-analysis aimed to evaluate the efficacy of probiotic supplementation during standard therapy on the eradication rate of H. pylori infection and incidence of therapy-related side effects. Four online databases were searched for eligible studies without language restriction. Review Manager (REVMAN, Version 5.3) was used to perform all data analyses. Forty articles including 5792 patients met our criteria and were included in the analysis. Notably, probiotic supplementation improved the eradication rate by approximately 10% relative to the control group [odds ratio (OR), 1.94, 95% confidence interval (CI): 1.70-2.22, P < 0.00001]. The incidence of total side effects (OR, 0.56, 95% CI: 0.45-0.70, P < 0.00001) and individual symptoms (e.g., diarrhea, vomiting and nausea, constipation, epigastric pain, taste disturbance) also decreased significantly with probiotic supplementation. No other differences in side effects were observed between the experimental and control groups. Moreover, a longer duration (≥10 days) of probiotic treatment had positive effects on both eradication rate of H. pylori and incidence of overall side effects.

Prophylactic effect of Lactobacillus plantarum KSFY06 on HCl/ethanol-induced gastric injury in mice

The present study was conducted to determine the prophylactic effect of Lactobacillus plantarum KSFY06 (LP-KSFY06) on HCl/ethanol-induced gastric injury in Kunming mice. The experimental mice were allocated into six groups: the normal group, HCl/ethanol treated group, HCl/ethanol + ranitidine treated group, HCl/ethanol + Lactobacillus delbrueckii subsp. Bulgaricus (LB) treated group, HCl/ethanol + low concentration of Lactobacillus plantans KSFY06 (LP-KSFY06-L) treated group, and HCl/ethanol + high concentration of Lactobacillus plantans KSFY06 (LP-KSFY06-H) treated group. The changes in daily body weight and food intake of the mice in the HCl/ethanol + LP-KSFY06-H treated group were the closest to those of the HCl/ethanol + ranitidine treated and normal groups. LP-KSFY06 significantly inhibited the formation of gastric mucosal lesions, reduced the area of gastric lesions, inhibited gastric-juice secretion, and increased pH compared with the HCl/ethanol treated group. After the treatment, the serum interleukin-6 (IL)-6, IL-12, tumor necrosis factor-α (TNF-α), and interferon-γ levels and the gastric-tissue IL-6 and IL-12 levels in the LP-KSFY06 (including LP-KSFY06-L and LP-KSFY06-H) group decreased compared with those in the HCl/ethanol treated group. The level of serum and gastric tissue malondialdehyde was lower and the nitric oxide, total superoxide dismutase, and glutathione activities in the LP-KSFY06 treated mice were higher than those in the HCl/ethanol treated mice. Quantitative polymerase chain reaction analysis and western blot analysis showed that LP-KSFY06 increased the mRNA and protein expression of the epidermal growth factor, epidermal growth factor receptor, vascular endothelial growth factor, inhibitor kappaB-α, neuronal nitric oxide synthase, and endothelial NOS and reduced the mRNA and protein expression of nuclear factor kappaB, inducible NOS, cyclooxygenase-2, TNF-α, and IL-1β in gastric tissues compared with the HCl/ethanol treated mice. These experimental results showed that a high concentration (1.0 × 109 CFU per kg B.W.) of LP-KSFY06 had a stronger effect on preventing gastric injury than a low concentration (1.0 × 108 CFU per kg B.W.) of LP-KSFY06. These results suggest that LP-KSFY06 has a potential probiotic effect in preventing gastric injury.

Microbiota: a novel regulator of pain

Among the various regulators of the nervous system, the gut microbiota has been recently described to have the potential to modulate neuronal cells activation. While bacteria-derived products can induce aversive responses and influence pain perception, recent work suggests that "abnormal" microbiota is associated with neurological diseases such as Alzheimer's, Parkinson's disease or autism spectrum disorder (ASD). Here we review how the gut microbiota modulates afferent sensory neurons function and pain, highlighting the role of the microbiota/gut/brain axis in the control of behaviors and neurological diseases. We outline the changes in gut microbiota, known as dysbiosis, and their influence on painful gastrointestinal disorders. Furthermore, both direct host/microbiota interaction that implicates activation of "pain-sensing" neurons by metabolites, or indirect communication via immune activation is discussed. Finally, treatment options targeting the gut microbiota, including pre- or probiotics, will be proposed. Further studies on microbiota/nervous system interaction should lead to the identification of novel microbial ligands and host receptor-targeted drugs, which could ultimately improve chronic pain management and well-being.

Probiotic L. gasseri strain (LG21) for the upper gastrointestinal tract acting through improvement of indigenous microbiota

Objective

To describe probiotics including a Lactobacillus gasseri strain LG21 used for the upper gastrointestinal tract, which are considered to act through improvement of indigenous microbiota inhabiting there.

Background and design

Because the early definition of probiotics emphasized their effects on improving the intestinal microbial ecology, their effects on the intestinal tract and its immunity have been considered common general benefits associated with probiotics. This conclusion was also based on a body of successful clinical trials whose endpoints were the prevention or treatment of intestinal diseases. In contrast to intestinal microbiota, our understanding of the role of gastric microbiota in human health and physiology remains poor, as the bacterial load in the stomach is considered too small to exert a significant effect due to the highly acidic environment of the human stomach. Therefore, the intervention using probiotics in the stomach is still limited at present.Results:In this article using representative 38 quoted articles, we first describe the gastric microbiota, as the indigenous microbiota in the stomach is thought to be significantly involved in the pathophysiology of this organ, since probiotics exert their beneficial effects through improving the resident microbiota. We then review the present status and future prospects of probiotics for the treatment of upper gastrointestinal diseases by quoting representative published articles, including our basic and clinical data.

Conclusions

Probiotics have been demonstrated to suppress Helicobacter pylori in the stomach, and are also expected to improve functional dyspepsia through the correction of dysbiotic gastric microbiota.

Treating Viral Diarrhea in Children by Probiotic and Zinc Supplements

PURPOSE

The aim of this study was to analyze the effects of probiotics and zinc supplements on the mean duration and frequency of acute diarrhea in children aged 6 months to 2 years.

METHODS

In this clinical trial of infants aged between 6 months and 2 years, eligible patients were divided into 3 groups: Zinc Receiving Group (ZRG), Probiotic Receiving Group (PRG), and a control group receiving supportive care alone. The frequency of diarrhea was evaluated in the test groups during the first 24 hours and 48-72 hours, along with the duration of hospitalization and diarrhea persistence for 3-7 days.

RESULTS

Diarrhea persisted for until the third day of admission in 100% of the infants in PRG compared with only 76.1% in ZRG. The relative risk of diarrhea persistence in the PRG was 1.31 times more than in ZRG until the third day. Also, 80% of diarrhea cases in the PRG persisted until the fourth day of admission, compared with 47.8% in the ZRG group, and this value was significant. The relative incidence of diarrhea persistence in the PRG was 36.4 times greater than in the ZRG until the day 4. Also, the percentage of post-treatment complications was 35.5% in the PRG and 2.6% in the ZRG, which was significant.

CONCLUSION

In our study, the effectiveness of zinc at a dose of 20 mg was higher than that of probiotics. The complications associated with zinc supplementation were lower than those of probiotics.

Immunopathological and molecular basis of functional dyspepsia and current therapeutic approaches

INTRODUCTION

Functional dyspepsia (FD) is widespread with 20% prevalence worldwide and a significant economic burden due to health care cost and constraints on daily activities of patients. Despite extensive investigation, the underlying causes of dyspepsia in a majority of patients remain unknown. Common complaints include abdominal discomfort, pain, burning, nausea, early satiety, and bloating. Motor dysfunction of the gut was long considered a major cause, but recent investigations suggest immune-based pathophysiological and molecular events in the duodenum are more probable contributing factors. Areas Covered: Inflammatory mediators and immune cells including duodenal eosinophils, intraepithelial lymphocytes, and T-cells have been implicated in the underlying cause of disease process, as have genetic factors. In this article, we critically reviewed findings, identified gaps in knowledge and suggested future directions for further investigation to identify targets and develop better therapeutic approaches. Expert commentary: Impaired gastric accommodation, slow gastric emptying, and increased visceral sensitivity have long been thought of as main causal factors of FD. However, more recent identification of eosinophilic degranulation and recruitment of T cells that induce mild duodenal inflammation are giving rise to new insights into immune-mediated pathophysiology. These insights offer promising avenues to explore for immune-mediated therapy in the future.

Role of the Duodenum in the Pathogenesis of Functional Dyspepsia: A Paradigm Shift

Functional dyspepsia (FD) is a common disorder characterized by chronic epigastric pain or burning, or bothersome postprandial fullness or early satiation, without a definitive organic cause. The pathogenesis of FD is likely heterogeneous. Classically, motor disorders, visceral hypersensitivity, and brain-gut interactions have been implicated in the pathophysiology of FD, but recently an important role for chronic low-grade inflammation and infection in FD has been reported and confirmed. Duodenal low-grade inflammation is frequently observed in FD in those with and without documented previous gastroenteritis. Duodenal eosinophils and in some cases mast cells may together or separately play a key role, and immune activation (eg, circulating homing small intestinal T cells) has been observed in FD. Low-grade intestinal inflammation in patients with FD may provoke impairment in motor-sensory abnormalities along the gastrointestinal neural axis. Among FD patients, the risk of developing dyspeptic symptoms after a bout of gastroenteritis is 2.54 (95% CI, 1.76–3.65) at more than 6 months after acute gastroenteritis. Gut host and microbial interactions are likely important, and emerging data demonstrate both quantitative and qualitative changes of duodenal mucosal and fecal microbiota in FD. Food antigens (eg, wheat proteins) may also play a role in inducing duodenal inflammation and dyspepsia. While causation is not established, the hypothesis that FD is a disorder of microscopic small intestinal inflammation in a major subset is gaining acceptance, opening the possibility of novel treatment approaches that may be able to alter the natural history of the disorder.

Effect of Lactobacillus gasseri BNR17 on irritable bowel syndrome: a randomized, double-blind, placebo-controlled, dose-finding trial

Lactobacillus gasseri BNR17 is a strain isolated from human breast milk. The objective of this randomized, double-blind, placebo-controlled, and preliminary dose-finding trial was to find the effective dose and evaluate the effect of Lb. gasseri BNR17 on irritable bowel syndrome (IBS) symptoms. A total of 55 volunteers aged over 20 years with body mass index over 23 kg/m² were randomized to intake a placebo, low-dose (BNR-L, 2 × 10⁸ CFU/day), intermediate-dose (BNR-M, 2 × 10⁹ CFU/day), or high-dose BNR (BNR-H, 2 × 5 × 10⁹ CFU/day) for four weeks. Questionnaire for IBS symptoms scores and Lb. gasseri BNR17 in feces were assessed at the beginning and end of the trial. Among IBS symptoms scores, abdominal pain score was significantly reduced in BNR-H group. Lb. gasseri BNR17 was detected in all intake groups except placebo. In the preliminary study, Lb. gasseri BNR17 was confirmed to have probiotic properties.

The Ameliorating Effect of Lactobacillus gasseri OLL2716 on Functional Dyspepsia in Helicobacter pylori-Uninfected Individuals: A Randomized Controlled Study

BACKGROUND/AIMS

Probiotics appear to improve Helicobacter pylori-associated dyspepsia via an inhibitory effect on H. pylori; however, uncertainty exists regarding their effects in H. pylori-uninfected individuals. We evaluated the efficacy of Lactobacillus gasseri OLL2716 (L. gasseri OLL2716) on H. pylori-uninfected individuals with functional dyspepsia (FD).

METHODS

A double-blind, parallel-group, placebo-controlled, randomized, controlled trial was performed. Participants were randomly assigned to ingest L. gasseri OLL2716-containing yogurt (L. gasseri OLL2716 group) or L. gasseri OLL2716-free yogurt (placebo group) for 12 weeks. Participants completed questionnaires that dealt with a global assessment as well as symptom severity. The per-protocol (PP) population was evaluated for efficacy in accordance with a plan prepared beforehand.

RESULTS

Randomization was performed on 116 individuals; the PP population consisted of 106 individuals (mean age 42.8 ± 9.0). The impressions regarding the overall effect on gastric symptoms were more positive in the L. gasseri OLL2716 group compared to that in the placebo group (statistical trend; p = 0.073). The elimination rate for major FD symptoms was 17.3 and 35.3% in the placebo and L. gasseri OLL2716 groups respectively (p = 0.048).

CONCLUSION

L. gasseri OLL2716 has beneficial effects on FD without H. pylori involvement.

Alteration in the gastric microbiota and its restoration by probiotics in patients with functional dyspepsia

Objective

The objective of this study was to comparatively analyse the gastric fluid (GF) microbiota between patients with functional dyspepsia (FD) and healthy controls (HC), and to assess the effect of probiotics on the microbiota.

Design

Twenty-four Japanese patients with FD who met the Rome III definition and 21 age-matched and gender-matched HC volunteers were enrolled. The patients with FD had been treated with LG21, a probiotic strain. The GF was sampled after an overnight fast using a nasogastric tube. The bile acids concentration was determined by ELISA. The V3-V4 region of 16S rRNA gene was amplified using bacterial DNA from the GF, and then about 30 000 high-quality amplicons per sample were grouped into operational taxonomic units for analyses.

Results

The ratio of GF samples in which the bile acids were detectable was significantly greater in the FD than in the HC groups. In the bacterial composition analysis at the phylum level, the GF microbiota had a Bacteroidetes > Proteobacteria abundance and an absence of Acidobacteria in the FD group, in contrast, the GF microbiota had a Bacteroidetes < Proteobacteria abundance and the presence of Acidobacteria in the HC group. Probiotic therapy in patients with FD shifted the composition of the GF microbiota to that observed in the HC volunteers.

Conclusions

Alteration in the GF microbiota was found in patients with FD compared with HC volunteers. Reflux of the small intestinal contents, including bile acid and intestinal bacteria, to the stomach was suggested to induce a bacterial composition change and be involved in the pathophysiology underlying FD. Probiotics appear effective in the treatment of FD through the normalisation of gastric microbiota.

Trial registration number

UMINCTR 000022026; Results.

Gastric microbiota in the functional dyspepsia patients treated with probiotic yogurt

OBJECTIVE

To investigate the structure of the gastric microbiota in functional dyspepsia (FD) and its role in the pathophysiology.

DESIGN

We compared the basic physiological properties of the gastric fluid (GF) and the structure of the microbiota in the GF of 44 healthy control (HC) participants and 44 patients with FD. We then treated the patients with FD with a yogurt containing a probiotic strain of Lactobacillus gasseri OLL2716 (LG21 yogurt) and investigated the effects on the bacteriological parameters and symptoms to examine the relationship between them.

RESULTS

The volume of GF recovered from the stomach after overnight fasting was greater in the patients with FD than in the HCs, and decreased in the patients with FD whose symptoms were improved by the LG21 yogurt treatment. An analysis using a terminal restriction fragment polymorphism method demonstrated that the overall structure of the bacterial community and the abundance of genus Prevotella in the GF of the patients in the FD group were significantly different from those in the HC group. In the patients with FD, this bacteriological change was restored by treatment with LG21 yogurt. A significant inverse correlation was found between the abundance of Prevotella and the severity of postprandial distress-like symptoms in patients with FD who received LG21 yogurt.

CONCLUSIONS

Significant dysbiosis was found in the GF microbiota of patients with FD and considered to be involved in the pathogenesis. The abundance of genus Prevotella in the GF may be used as a biomarker of the efficacy of the treatment of FD.

TRIAL REGISTRATION NUMBER

UMINCTR000022026.