UMIN-CTR Clinical Trial
| Unique ID issued by UMIN | UMIN000061547 |
|---|---|
| Receipt number | R000070314 |
| Scientific Title | Efficacy of probiotics (Bifidobacterium longum BB536) for intestinal symptoms of post-gastrectomy syndrome, including malodorous flatus and defecation disorders: study protocol for a randomized controlled trial |
| Date of disclosure of the study information | 2026/05/15 |
| Last modified on | 2026/05/07 15:15:52 |
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Basic information
Public title
A Study to Evaluate the Effects of Bifidobacterium longum BB536 on Malodorous Flatus and Bowel Dysfunction After Gastrectomy
Acronym
GAS-BB Study(Gastrectomy-Associated Symptoms and BB536 Study)
Scientific Title
Efficacy of probiotics (Bifidobacterium longum BB536) for intestinal symptoms of post-gastrectomy syndrome, including malodorous flatus and defecation disorders: study protocol for a randomized controlled trial
Scientific Title:Acronym
GAS-BB Study(Gastrectomy-Associated Symptoms and BB536 Study)
Region
| Japan |
Condition
Condition
post-gastrectomy syndrome
Classification by specialty
| Gastrointestinal surgery |
Classification by malignancy
Others
Genomic information
NO
Objectives
Narrative objectives1
The aim of this study is to evaluate the efficacy of probiotic (Bifidobacterium longum BB536) intake in improving bowel symptoms associated with post-gastrectomy syndrome, particularly malodorous flatus and bowel dysfunction, in patients who have undergone gastrectomy for gastric cancer, including distal gastrectomy, total gastrectomy, and proximal gastrectomy. In addition, this study aims to investigate the sustainability of symptom improvement following BB536 intake.
Furthermore, differences in gut microbiota composition before and after BB536 administration, as well as according to the presence or absence of symptoms, will be analyzed. The association between bowel symptoms and alterations in gut microbiota will also be evaluated.
Basic objectives2
Efficacy
Basic objectives -Others
Trial characteristics_1
Trial characteristics_2
Developmental phase
Assessment
Primary outcomes
Improvement rate of symptoms related to malodorous flatus (score for questionnaire item 5):
This outcome will be evaluated in patients with flatus-related symptoms.
Symptom improvement will be defined as a decrease in the score for questionnaire item 5 from 4-7 points at enrollment to 1-3 points at 4 weeks after enrollment.
The improvement rate will be defined as the proportion of patients who achieved symptom improvement among the total number of patients analyzed in each group (BB536 intervention group and non-intervention group).
Key secondary outcomes
Secondary Outcomes
Secondary outcomes will be evaluated in patients with flatus-related symptoms. Baseline is defined as the time of study enrollment, and 4 weeks after enrollment is defined as 4 weeks after the initiation of BB536 intake or the start of the observation period. Using the modified PGSAS-37 questionnaire, changes in the score for flatus-related symptoms (item 5), changes in the mean score of all items excluding item 5, and changes in the mean scores of the subscales (indigestion, diarrhea, and constipation) will be evaluated. Mean scores will be calculated by dividing the sum of the relevant item scores by the number of items. Scores at 4 weeks after enrollment will also be evaluated. In the BB536 intervention group, the modified PGSAS-37 questionnaire will additionally be administered at 8 and 12 weeks after enrollment to evaluate the sustainability of symptom improvement.
Exploratory Outcomes
Stool samples will be collected from both symptomatic and asymptomatic participants for gut microbiota analysis. Relative abundance of bacterial taxa, alpha diversity (faith_pd, Shannon, chao1, evenness, observed_otus), and beta diversity (bray_curtis, jaccard, unweighted_unifrac, weighted_unifrac) will be calculated. Principal coordinate analysis (PCoA) will also be performed, and the top three PCoA scores will be obtained. Furthermore, associations between gut microbiota indices and flatus-related symptom scores will be investigated._
Base
Study type
Interventional
Study design
Basic design
Parallel
Randomization
Randomized
Randomization unit
Individual
Blinding
Open -no one is blinded
Control
No treatment
Stratification
Dynamic allocation
Institution consideration
Blocking
Concealment
Intervention
No. of arms
3
Purpose of intervention
Treatment
Type of intervention
| Food |
Interventions/Control_1
Participants with a score of 4-7 on questionnaire item 5 (see Section 6.4.4, Assessment Items) will be defined as having flatus-related symptoms, whereas those with a score of 1-3 will be defined as not having flatus-related symptoms. Participants with flatus-related symptoms will be randomly assigned to either the BB536 intervention group or the non-intervention group in a randomized controlled trial.
BB536 intervention group:
Participants will orally receive one sachet per day of freeze-dried Bifidobacterium longum BB536 powder (50 billion CFU per 2 g sachet) for 4 weeks. Adherence will be monitored using a medication calendar. After 4 weeks of oral intake, the questionnaire survey and stool sample collection will be repeated.
Interventions/Control_2
Non-intervention group:
No intervention will be performed, and participants will undergo a 4-week observation period. After the 4-week observation period, the questionnaire survey and stool sample collection will be repeated.
Interventions/Control_3
Asymptomatic observational group:
No intervention will be performed. Only stool samples will be collected at the time of enrollment for gut microbiota analysis.
Interventions/Control_4
Interventions/Control_5
Interventions/Control_6
Interventions/Control_7
Interventions/Control_8
Interventions/Control_9
Interventions/Control_10
Eligibility
Age-lower limit
| 18 | years-old | <= |
Age-upper limit
| Not applicable |
Gender
Male and Female
Key inclusion criteria
Participants aged 18 years or older, regardless of sex
Participants who underwent gastrectomy at our department, including distal gastrectomy, proximal gastrectomy, or total gastrectomy, and for whom at least 8 weeks have elapsed since surgery
Participants who received an explanation of the study and provided written informed consent based on their own free will and sufficient understanding of the study procedures
Key exclusion criteria
Participants with a history of antibiotic treatment within 4 weeks prior to the initiation of oral BB536 intake
Participants who routinely use medications for constipation (including osmotic laxatives, stimulant laxatives, bulk-forming laxatives, and epithelial function-modifying agents), antidiarrheal agents, or probiotic preparations
Participants who routinely consume health foods or supplements containing lactic acid bacteria, bifidobacteria, oligosaccharides, dietary fiber, or similar products
Participants who routinely use digestive enzyme supplements
Participants with a known allergy to Bifidobacterium longum
Participants who expressed unwillingness to participate in this study
Participants judged by the principal investigator to be unsuitable for participation in this study for any other reason
Target sample size
99
Research contact person
Name of lead principal investigator
| 1st name | Motohiro |
| Middle name | |
| Last name | Imano |
Organization
Kindai University Hospital Cancer Center
Division name
Outpatient Chemotherapy Center
Zip code
590-0197
Address
1-14-1 Mihara-dai, Minami-ku, Sakai, Osaka 590-0197, Japan
TEL
072-288-7222
imano@med.kindai.ac.jp
Public contact
Name of contact person
| 1st name | Naoko |
| Middle name | |
| Last name | Kounami |
Organization
Kindai University Faculty of Medicine
Division name
Department of Surgery
Zip code
590-0197
Address
1-14-1 Mihara-dai, Minami-ku, Sakai, Osaka 590-0197, Japan
TEL
072-288-7222
Homepage URL
naoko.kounami.0205@gmail.com
Sponsor or person
Institute
Kindai University
Institute
Department
Personal name
Funding Source
Organization
MORINAGA MILK INDUSTRY CLINICO CO., LTD
Organization
Division
Category of Funding Organization
Profit organization
Nationality of Funding Organization
Other related organizations
Co-sponsor
Name of secondary funder(s)
IRB Contact (For public release)
Organization
Ethics Committee of Kindai University Faculty of Medicine
Address
1-14-1 Mihara-dai, Minami-ku, Sakai, Osaka 590-0197, Japan
Tel
072-288-7222
zizen@med.kindai.ac.jp
Secondary IDs
Secondary IDs
NO
Study ID_1
Org. issuing International ID_1
Study ID_2
Org. issuing International ID_2
IND to MHLW
Institutions
Institutions
Other administrative information
Date of disclosure of the study information
| 2026 | Year | 05 | Month | 15 | Day |
Related information
URL releasing protocol
Publication of results
Unpublished
Result
URL related to results and publications
Number of participants that the trial has enrolled
Results
Results date posted
Results Delayed
Results Delay Reason
Date of the first journal publication of results
Baseline Characteristics
Participant flow
Adverse events
Outcome measures
Plan to share IPD
IPD sharing Plan description
Progress
Recruitment status
Enrolling by invitation
Date of protocol fixation
| 2026 | Year | 02 | Month | 19 | Day |
Date of IRB
| 2026 | Year | 03 | Month | 05 | Day |
Anticipated trial start date
| 2026 | Year | 04 | Month | 20 | Day |
Last follow-up date
| 2027 | Year | 08 | Month | 31 | Day |
Date of closure to data entry
| 2028 | Year | 08 | Month | 31 | Day |
Date trial data considered complete
Date analysis concluded
| 2028 | Year | 08 | Month | 31 | Day |
Other
Other related information
Management information
Registered date
| 2026 | Year | 05 | Month | 13 | Day |
Last modified on
| 2026 | Year | 05 | Month | 07 | Day |
Link to view the page
Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000070314
