Bacillus Probiotics With Bismuth Quadruple Therapy for Helicobacter Pylori Infection

September 14, 2026 updated by: Anabio R&D

Clinical Efficacy and Gut Microbiota Effects of High-Dose Single-Strain and Multi-Strain Bacillus Probiotics as Adjunctive Therapy to Bismuth Quadruple Therapy for Helicobacter Pylori Eradication: A Randomised, Double-Blind, Placebo-Controlled Trial

Helicobacter pylori (H. pylori) is a very common gastrointestinal disease that colonises the human gastric mucosa and is a primary risk factor for chronic gastritis, peptic ulcer disease, and gastric cancer. The standard first-line treatment for H. pylori eradication is bismuth-containing quadruple therapy. While effective, this aggressive, multi-antibiotic regimen frequently induces significant gastrointestinal adverse effects and severe disruption of the normal gut microbiota (dysbiosis). These side effects often lead to poor patient compliance, which in turn contributes to treatment failure and the increasing global challenge of antibiotic resistance.

Emerging clinical evidence strongly supports the use of probiotics as an adjuvant therapy to alleviate antibiotic-associated side effects and significantly aid in restoring intestinal balance. Spore-forming Bacillus species, specifically Bacillus clausii, Bacillus subtilis, and Bacillus coagulans, are particularly advantageous due to their natural resistance to acidic gastric conditions and concurrent antibiotic administration, allowing them to remain viable and active during the intensive eradication therapy.

This clinical trial is designed as a randomised, double-blind, placebo-controlled study to evaluate the clinical efficacy, adverse effects, and treatment adherence of a standard four-drug bismuth-containing regimen for the treatment of H. pylori infection when combined with single-strain and multi-strain Bacillus probiotics.

The trial is conducted in the Gastroenterology Department of Tam Anh Hospital. 336 participants diagnosed with H. pylori infection and prescribed the standard 14-day bismuth-containing quadruple therapy are randomly divided and allocated to receive either a single-strain probiotic (LiveSpo Clausy), a multi-strain probiotic (LiveSpo DIA 30), or an identical placebo.

Over 8 weeks of follow-up, participants will be assessed at predefined time points for antibiotic-associated adverse events, gastrointestinal symptoms, stool form, treatment adherence, and Helicobacter pylori eradication status. Stool samples will be collected before and after treatment to evaluate faecal IgA levels, the presence of Bacillus strains, and changes in gut microbiota using real-time PCR, ELISA, and 16S rRNA sequencing.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Helicobacter pylori (H. pylori) infection affects roughly half of the world's population, making it a very common digestive disease. In developing countries, infection rates are especially high, with 85-95% of the population potentially infected with H. pylori, making this disease a major public health concern. H. pylori mainly infects and lives in the mucous membrane of the stomach lining, enabling it to persist for long periods and lead to chronic infection. Its survival in the stomach's harsh acidity is primarily due to urease, an enzyme that breaks down urea into ammonia, neutralizing the stomach acid. In Vietnam, historically, clarithromycin-based triple therapy achieved eradication rates exceeding 90%. However, rising global antibiotic resistance has reduced its efficacy to below 70%, leading to its removal from first-line recommendations in regions with high resistance. As a result, bismuth-containing quadruple therapy, which includes a proton pump inhibitor (PPI), tetracycline, metronidazole, and bismuth, has become the standard first-line and rescue treatment for H. pylori eradication.

While this regimen is highly effective, yielding eradication rates between 90.4% and 99.3%, it frequently induces significant gastrointestinal adverse effects. Clinical data indicate that 54.1% to 67.0% of patients experience symptoms such as dizziness, nausea, vomiting, diarrhea, black stools, fatigue, and anorexia. Furthermore, the high-dose administration of tetracycline and metronidazole causes severe disruption of the normal gut microbiota (dysbiosis). This dysbiosis is characterized by a marked decrease in beneficial microbial populations, such as Bacteroidetes and Actinobacteria, alongside a concerning overgrowth of opportunistic pathogens, such as Proteobacteria. These severe side effects often lead to poor patient compliance, causing patients to reduce dosages or prematurely discontinue therapy. This lack of adherence, in turn, contributes to treatment failure and exacerbates the increasing global challenge of antibiotic resistance.

The use of spore-forming probiotic strains from the genus Bacillus in Helicobacter pylori eradication regimens has recently garnered considerable attention within the scientific community, yielding promising outcomes in randomized controlled trials (RCTs). Multicenter studies have demonstrated that supplementation with Bacillus clausii alongside antibiotic regimens significantly reduces the incidence of antibiotic-associated diarrhoea (AAD) and other gastrointestinal symptoms, including nausea and a bitter taste. This, in turn, enhances drug tolerance and treatment adherence among patients. Additionally, research on Bacillus subtilis and Bacillus coagulans offers substantial medical evidence concerning their direct and indirect mechanisms of action. In vitro studies indicate that B. subtilis may inhibit H. pylori growth through secretion of natural antimicrobial compounds, particularly amicoumacin A, while other Bacillus-derived bacteriocins and lipopeptides may contribute to broader antimicrobial activity. In contrast, B. coagulans has demonstrated efficacy in modulating local immune responses, reducing inflammatory cytokines, and preserving the integrity of the gastric mucosa against bacterial damage.

Although there is substantial evidence for the effectiveness of Bacillus species, data on their effectiveness in supportive treatment with bismuth-containing quadruple drug regimens remain limited, particularly studies evaluating the simultaneous effects on bacterial eradication, adverse effects, and changes in mucosal immune response and gut microbiota.

Therefore, this study was conducted with two main objectives:

  1. To evaluate the rate and severity of adverse effects, as well as treatment compliance of bismuth-containing quadruple drug regimens (BQT) when combined with single-strain (B. clausii - LiveSpo Clausy) or with multi-strain (B. subtilis, B. clausii, B. coagulans - LiveSpo DIA 30) spore probiotics;
  2. Evaluate the H. pylori eradication rate along with changes in secretory IgA (sIgA) and gut microbiota before and after H. pylori eradication treatment with the BQT regimen combined with spore-forming probiotics (single-strain, multi-strain Bacillus).

This study is designed as a randomized, double-blind, placebo-controlled trial conducted at the Gastroenterology Department of Tam Anh Hospital. The study population consists of 336 eligible adult patients with confirmed active Helicobacter pylori infection, as determined by standardized diagnostic tests, specifically the 13C-Urea Breath Test. To ensure balanced comparison, participants will be randomly assigned in a 1:1:1 ratio to three parallel groups, with 112 patients in each group. All randomized patients will receive a standard 14-day bismuth-containing quadruple therapy, based on group assignment, patients will receive either a single-strain probiotic (LiveSpo Clausy), a multi-strain probiotic (LiveSpo DIA 30), or a placebo (RO water). To maintain the double-blind design, all adjunctive ampoules are identical in appearance, labelling, and packaging. All groups received the assigned probiotic product at a dose of 3 ampoules per day for 2 weeks. After completing the antibiotic course, participants continued probiotics at two ampoules per day for an additional six weeks.

A structured monitoring protocol will be implemented at specific intervals: Baseline (Week 0), Week 1, Week 2, Week 4, and Week 8. During these visits, standardized questionnaires will assess patient compliance, the incidence of gastrointestinal adverse effects, and overall symptom resolution. Subsequent stool samples will be collected for post-treatment laboratory analyses to quantify Bacillus colonization and track dynamic shifts in the gut microbiota. Finally, the primary clinical endpoint, successful H. pylori eradication, will be objectively confirmed 6 weeks after the completion of the antibiotic therapy.

Expect outcomes:

  • Primary Outcome Measures: (i) Antibiotic-Associated Adverse Event Rate and Severity; (ii) Change in Gastrointestinal Symptom Score; (iii) Change in Stool Consistency.
  • Secondary Outcome Measures: (i) Medication Adherence via MARS-5; (ii) Pill Count Adherence Rate.
  • Exploratory Outcome Measures: (i) H. pylori Eradication Rate; (ii) Change in Faecal Secretory IgA (sIgA) Concentration; (iii) Gut Microbiota Composition and Diversity; (iv) Detection of Probiotic Bacillus Spores in Stool.

Tabular analysis is performed on dichotomous variables using the χ2 test or Fisher's exact test when the expected value of any cell is below five. Continuous variables are compared using either the t-test or the Mann-Whitney test when the data are not normally distributed. Statistical and graphical analyses are conducted using GraphPad Prism v8.4.3 software (GraphPad Software, CA, USA). The significance level for all analyses is set at p < 0.05.

Study Type

Interventional

Enrollment (Estimated)

336

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients aged 18 to 65 years;
  • Diagnosed with H. pylori infection by the 13C-urea breath test or the rapid urease test;
  • Indicated for H. pylori eradication treatment with the four-drug bismuth regimen (BQT);
  • Agree to participate in the study and have been informed and signed the consent form

Exclusion Criteria:

  • Active bleeding gastric or duodenal ulcer.
  • Use of antibiotics, acid-suppressing drugs (PPIs, H2RAs), non-steroidal anti-inflammatory drugs (NSAIDs), laxatives, antidiarrheals, or probiotics (excluding yogurt) within at least 4 weeks before participating in the study, except for laxatives used as part of the study's endoscopic preparation procedure.
  • Chronic inflammatory bowel disease (IBD), acute intestinal infection, gastrointestinal cancer (stomach cancer, colon cancer), acute or chronic pancreatitis, immunosuppression (including prolonged corticosteroid use), or psychiatric disorders.
  • Alcohol abuse, history of delirium tremens, or alcoholic liver disease.
  • Pregnant or breastfeeding women.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Supportive Care
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Control group

The Control group receives the standard treatment regimen, combined with RO water at a dose of 3 ampoules/day for 2 weeks; then continues using 2 ampoules/day for the next 6 weeks.

The probiotic product is used at least 2 hours apart from the antibiotic dose.

The BQT routine treatment regimen is:

  • Esomeprazole 40 mg: take 1 tablet twice daily, 30-60 minutes before meals.
  • Tetracycline 500 mg: take 1 tablet four times daily, 30 minutes after meals.
  • Tinidazole 500 mg: take 1 tablets three times daily (after breakfast, lunch, dinner) 30 minutes after meals.
  • Bismuth subcitrate 120 mg: take 1 tablet four times daily, 30 minutes after meals.
Other: RO water
RO water (Aquafina, PepsiCo) produced under ISO 9001:2015 and ISO 22000:2018 standards. The RO water ampoules are produced using a similar process as the LiveSpo Clausy / Dia30 but contain 5 mL of high-quality RO water from Aquafina.
Experimental: Clausy group

The Clausy group receives the standard treatment regimen, combined with RO water plus B. clausii at 2 billion CFU/5 ml (LiveSpo® CLAUSY) at a dose of 3 ampoules/day for 2 weeks; then continues using 2 ampoules/day for the next 6 weeks.

The probiotic product is used at least 2 hours apart from the antibiotic dose.

The BQT routine treatment regimen is:

  • Esomeprazole 40 mg: take 1 tablet twice daily, 30-60 minutes before meals.
  • Tetracycline 500 mg: take 1 tablet four times daily, 30 minutes after meals.
  • Tinidazole 500 mg: take 1 tablets three times daily (after breakfast, lunch, dinner) 30 minutes after meals.
  • Bismuth subcitrate 120 mg: take 1 tablet four times daily, 30 minutes after meals.
Combination product: LiveSpo CLAUSY
LiveSpo® CLAUSY has a registration number 4071/2021/ĐKSP issued by the Food Safety Department of the Ministry of Health in Vietnam.
Experimental: Dia 30 group

The Dia 30 group receives the standard treatment regimen, combined with RO water plus B. Clausii, B. subtilis, B. coagulans at 5 billion CFU/5 ml (LiveSpo® DIA 30) at a dose of 3 ampoules/day for 2 weeks; then continues using 2 ampoules/day for the next 6 weeks.

The probiotic product is used at least 2 hours apart from the antibiotic dose.

The BQT routine treatment regimen is:

  • Esomeprazole 40 mg: take 1 tablet twice daily, 30-60 minutes before meals.
  • Tetracycline 500 mg: take 1 tablet four times daily, 30 minutes after meals.
  • Tinidazole 500 mg: take 1 tablets three times daily (after breakfast, lunch, dinner) 30 minutes after meals.
  • Bismuth subcitrate 120 mg: take 1 tablet four times daily, 30 minutes after meals.
Combination product: LiveSpo DIA30
LiveSpo® DIA30 has a registration number 6547/2019/ĐKSP issued by the Food Safety Department of the Ministry of Health in Vietnam.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Antibiotic-Associated Adverse Event Rate and Severity
Time Frame: Weeks 0, 1, 2, 4 and 8
The proportion and severity of antibiotic-associated adverse events during H. pylori eradication therapy are assessed using the Antibiotic-Associated Adverse Events Questionnaire (AAE-Q) during the first 2 weeks of treatment. The assessed symptoms include: fatigue, loss of appetite, dizziness, headache, diarrhoea, and nausea/vomiting. The key evaluation time point will be week 2, with changes assessed from baseline/week 0 to week 2. The week 1, 4, and 8 visits will serve as interim supportive time points.
Weeks 0, 1, 2, 4 and 8
Change in Gastrointestinal Symptom Score
Time Frame: Weeks 0, 2, and 8
Gastrointestinal symptoms are assessed using the Gastrointestinal Symptom Rating Scale (GSRS), at baseline, after completion of H. pylori eradication therapy, and during the post-treatment follow-up period. The key evaluation time point will be week 2, with changes assessed from baseline/week 0 to week 2. The week 8 visits will serve as interim supportive time points.
Weeks 0, 2, and 8
Change in Stool Consistency
Time Frame: Weeks 0, 2, and 8
Stool consistency will be assessed using the Bristol Stool Scale (BSS) at baseline, after completion of H. pylori eradication therapy, and during the post-treatment follow-up period. The key evaluation time point will be week 2, with changes assessed from baseline/week 0 to week 2. The week 8 visits will serve as interim supportive time points.
Weeks 0, 2, and 8

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Treatment Adherence
Time Frame: Weeks 1 and 2
Treatment adherence during 2 week of of H. pylori eradication therapy is measured with the Medication Adherence Report Scale-5 (MARS-5), consisting of five questions that assess medication-taking behaviors such as forgetting to take medication, altering the dose, discontinuing medication, skipping doses, and taking less medication than prescribed. The key evaluation time point will be week 2 and week 1 point will serve as an interim supportive time point.
Weeks 1 and 2
Pill Count Adherence Rate
Time Frame: Weeks 1 and 2
Adherence to H. pylori eradication therapy will be assessed by counting the number of medications used compared with the number prescribed. At each follow-up time point, participants who have taken ≥90% of the prescribed medications will be considered adherent to treatment. The key evaluation time point will be week 2.
Weeks 1 and 2

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
H. pylori Eradication Rate
Time Frame: Weeks 0 and 8
H. pylori eradication will be assessed using the 13C-urea breath test at baseline, after completion of H. pylori eradication therapy, and during the post-treatment follow-up period. The key evaluation time point will be week 8, with changes assessed from baseline/week 0 to week 8.
Weeks 0 and 8
Change in Fecal Secretory IgA Concentration
Time Frame: Weeks 0, 2 and 8
Changes in fecal sIgA concentration are measured and compared within each group over time and among the study groups at 3 time points. The main exploratory comparison will be the change from Week 0 to Week 2, while Week 8 will serve as a follow-up time point to evaluate sustained or delayed changes
Weeks 0, 2 and 8
Gut microbiota composition
Time Frame: Weeks 0 and 2
Changes in gut microbiota composition are evaluated using 16S rRNA gene sequencing of stool samples. The outcomes include diversity indices and the relative taxonomic composition at major levels such as phylum, family, and genus. The key evaluation time point will be week 2, with changes assessed from baseline/week 0 to week 2.
Weeks 0 and 2
Detection of probiotic Bacillus spores in stool
Time Frame: Weeks 0, 2, and 8
Presence of B. subtilis, B. clausii, and B. coagulans spores in stool as determined by real-time PCR, used as an exploratory indicator of exposure to the assigned probiotic products and adherence to the intervention across 3 main follow-up timepoints. The main exploratory time point will be Week 2, while Week 8 will be used as a follow-up time point.
Weeks 0, 2, and 8

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Anabio R&D

Collaborators

Tam Anh Research Institute

Investigators

  • Principal Investigator: Tien Tran Dao, MSc, M.D., Ha Noi Medical University
  • Study Chair: Khanh Tran Van, Prof.M.D, Ha Noi Medical University
  • Study Chair: Anh Nguyen Thi Van, Spobio Research Center, Anabio R&D

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

October 1, 2026

Primary Completion (Estimated)

October 1, 2027

Study Completion (Estimated)

December 1, 2027

Study Registration Dates

First Submitted

September 14, 2026

First Submitted That Met QC Criteria

September 14, 2026

First Posted (Actual)

September 18, 2026

Study Record Updates

Last Update Posted (Actual)

September 18, 2026

Last Update Submitted That Met QC Criteria

September 14, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • IRB.TAHN 178

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Data or samples shared will be coded, with no PHI included. Approval of the request and execution of all applicable agreements (i.e., a material transfer agreement) are prerequisites to the sharing of data with the requesting party.

IPD Sharing Time Frame

Data requests can be submitted 9 months after article publication and will be made accessible for up to 24 months. Extensions will be considered on a case-by-case basis.

IPD Sharing Access Criteria

Access to trial IPD can be requested by qualified researchers engaging in independent scientific research. It will be provided following the review and approval of a study protocol, informed consent form (ICF), and clinical study report (CSR). For more information or to sub

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • ICF
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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