NCT07453823

Brief Summary

The study is a single-center, randomized, double-blind, placebo-controlled study in middle-aged to elderly adults with excessive body weight. The study includes an 8-week intervention period followed by a 2-week follow-up period. The study will evaluate the effect of a synbiotic consisting of two probiotic strains and a prebiotic. The aim is to investigate the effect of the synbiotic on modulating the gut microbiota and improving markers of gastrointestinal permeability and integrity and gastrointestinal discomfort.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
90

participants targeted

Target at P50-P75 for not_applicable

Timeline
6mo left

Started Mar 2026

Shorter than P25 for not_applicable

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress35%
Mar 2026Dec 2026

First Submitted

Initial submission to the registry

February 24, 2026

Completed
10 days until next milestone

First Posted

Study publicly available on registry

March 6, 2026

Completed
12 days until next milestone

Study Start

First participant enrolled

March 18, 2026

Completed
9 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 1, 2026

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

December 1, 2026

Last Updated

April 15, 2026

Status Verified

April 1, 2026

Enrollment Period

9 months

First QC Date

February 24, 2026

Last Update Submit

April 14, 2026

Conditions

Keywords

Gastrointestinal MicrobiomeSynbiotic

Outcome Measures

Primary Outcomes (1)

  • Bifidobacterium abundance

    Change in total relative abundance of Bifidobacterium from baseline to 8 weeks assessed from fecal samples. Abundance is calculated based on shotgun metagenomic sequencing.

    From baseline to end of intervention at 8 weeks

Secondary Outcomes (11)

  • Stool frequency

    From baseline to end of intervention at 8 weeks

  • Fecal acetate

    From baseline to end of intervention at 8 weeks.

  • Fecal propionate

    From baseline to end of intervention at 8 weeks.

  • Fecal butyrate

    From baseline to end of intervention at 8 weeks

  • Zonulin

    From baseline to end of intervention at 8 weeks

  • +6 more secondary outcomes

Other Outcomes (22)

  • Recovery of probiotic strains

    Baseline, 3 weeks, 8 weeks (end of intervention) and 2 weeks of follow-up

  • Total relative abundance of Bifidobacterium

    Baseline, 3 weeks, 8 weeks (end of intervention) and 2 weeks of follow-up.

  • Microbiome composition and taxonomic profiles

    Baseline, 3 weeks, 8 weeks (end of intervention) and 2 weeks of follow-up

  • +19 more other outcomes

Study Arms (2)

Synbiotic

ACTIVE COMPARATOR

Synbiotic dietary supplement

Dietary Supplement: Synbiotic

Placebo

PLACEBO COMPARATOR

Identical looking placebo consisting of maltodextrin

Dietary Supplement: Placebo

Interventions

SynbioticDIETARY_SUPPLEMENT

Synbiotic \- Given daily for 56 days

Synbiotic
PlaceboDIETARY_SUPPLEMENT

Placebo \- Given daily for 56 days

Placebo

Eligibility Criteria

Age50 Years - 70 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Be able to give informed consent.
  • Be between 50 to 70 years of age (inclusive).
  • BMI ranging from 25.0 and 35.0 kg/m²
  • Willing to maintain current level of physical activity and diet during the participation in the study.
  • Experience ≤3 bowel movements per week within the month prior to screening
  • Participants reported subclinical mild to moderate gastrointestinal complaints as defined by GSRS-IBS score 20-45 at screening.
  • Willing to consume the study product daily for the duration of the study.
  • Willing to eat the same meal the evening before visiting site (visit 2 to visit 5).
  • Participants are eligible for randomization if they fulfill the following two criteria based on the diary recordings during the run-in period prior to visit 2 9. Average GSRS-IBS composite symptom score between 20-45 during the two-week run-in period Record ≤6 bowel movements in the daily diary during the two-week run-in period

You may not qualify if:

  • Has a history of drug and/or alcohol abuse.
  • Has food allergies, or other issues with foods, that would preclude intake of the study products.
  • Smoking, chewable tobacco and/or vaping and/or use of other nicotine products.
  • Has any significant acute or chronic coexisting health conditions that would prevent them from fulfilling the study requirements, put the Participant at risk or would confound the interpretation of the study results as judged by the investigator on the basis of medical history and routine laboratory test results. Excluded health conditions include:
  • diagnosis of GI disease (e.g. gastric or duodenal ulcers, inflammatory bowel disease, colon cancer) or irritable bowel syndrome (IBS)
  • GI surgery that might have an effect on gastrointestinal tract function except cholecystectomy and appendectomy in the past 5 years or any major bowel resection at any time.
  • history of CVD
  • uncontrolled hypertension
  • Currently or recently taking a medication that the investigator believes would interfere with the objectives of the study or pose a safety risk or confound the interpretation of the study results. Prohibited medications include:
  • systemic antimicrobial medication (including suppositories) within 4 weeks prior to visit 1
  • OTC medications, for digestive symptoms such as PPIs, anti-spasmodics, laxatives, anti-diarrheic drugs within 2 weeks prior to visit 1
  • \. Individuals who, in the opinion of the investigator, are considered to be poor attendees or unlikely for any reason to be able to comply with the study.
  • \. Participants may not be participating in other clinical studies. If the participant has previously taken part in an experimental study, the Investigator must ensure sufficient time has elapsed before entry to this study to ensure the integrity of the results.
  • c. immunosuppressant drugs within the 4 weeks prior to the visit 1 d. systemic steroids within the 4 weeks prior to the visit 1 6. Regular oral non-steroidal anti-inflammatory (NSAIDs) within 1 week prior to visit 1 (topical NSAIDS allowed, Low-dose prophylactic aspirin use is acceptable if stable for 3 months prior to screening.) 7. Current or recent (in the past 4 weeks prior to visit 1) use of prohibited nutritional and non-nutritional supplements, that the investigator believes would interfere with the objectives of the study or pose a safety risk or confound the interpretation of the study results, including:
  • a. Herbal supplements for digestive symptoms b. Large doses of vitamins and minerals, unless in stable dose c. Probiotic supplements d. Iron supplements 8. Current or recent (in the past 2-weeks) use of prohibited foods including yoghurts containing probiotics.
  • +1 more criteria

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Atlantia Clinical Trials Ltd

Cork, Blackpool, T23 R50R, Ireland

RECRUITING

MeSH Terms

Interventions

Synbiotics

Intervention Hierarchy (Ancestors)

PrebioticsDietary SupplementsFoodDiet, Food, and NutritionPhysiological PhenomenaProbioticsFood and Beverages

Study Officials

  • Timothy G Dinan, Professor

    Atlantia Clinical Trials Ltd

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Sara Engel, PhD

CONTACT

Emma Harrington

CONTACT

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
QUADRUPLE
Who Masked
PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
Masking Details
Quardrople
Purpose
OTHER
Intervention Model
PARALLEL
Model Details: A randomized, double-blind, placebo-controlled trial of 8-week intervention and a 2-week follow-up period in a group of middle-aged to elderly adults with GI discomfort
Sponsor Type
INDUSTRY
Responsible Party
SPONSOR

Study Record Dates

First Submitted

February 24, 2026

First Posted

March 6, 2026

Study Start

March 18, 2026

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

December 1, 2026

Last Updated

April 15, 2026

Record last verified: 2026-04

Data Sharing

IPD Sharing
Will not share

Locations