An Intervention Study in Healthy Infants Aged 0-6 Months With Probiotics Lacticaseibacillus Rhamnosus LRa05 (LRa05) and Bifidobacterium Animalis Subsp. Lactis BLa80 (BLa80) vs. Placebo, for Promoting Gut Microbiome Development. (SMILE)

March 26, 2026 updated by: Gene Dempsey, University College Cork

The probiotics Bifidobacterium animalis subsp. lactis BLa80 and Lacticaseibacillus rhamnosus LRa05 have potential to enhance infant health and development based on previous research conducted on human infants.

Bifidobacterium animalis subsp. lactis BLa80 was isolated from healthy breast milk samples.

Ten clinical studies have been conducted using this strain, including randomized, double-blind, placebo-controlled trials, involving over 700 clinical subjects, adults and children. Based on the results from these studies, functional benefits associated with ingestion of this probiotic include relief of diarrhea, relief of constipation, improved sleep quality, resistance to H. pylori infection, modulation of gut microbiota, promotion of infant growth and development, gestational diabetes management and emotional management.

Lacticaseibacillus rhamnosus LRa05 was isolated from healthy baby faeces. Six clinical studies have been conducted, involving randomized, double-blind, placebo-controlled studies using this strain, involving over 500 clinical subjects. Based on the results from these studies, functional benefits associated with ingestion of this probiotic include relief of diarrhea, relief of eczema, resistance to H. pylori infection, modulation of gut microbiota, promotion of infant growth and development, and gestational diabetes management.

This proposal describes a three-year collaboration with APC Microbiome Ireland, INFANT Research Centre and WeCare to conduct clinical studies to investigate the effects of probiotics (Bifidobacterium animalis subsp. lactis BLa80 and Lacticaseibacillus rhamnosus LRa050), compared to a placebo, on the growth of infants and toddlers and the development of their gut microbiota. The focus of this study is on infant growth and gut microbiota development in infants up to 6 months old.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

The primary aim is to describe the impact of supplementation with the probiotics LRa05 and BLa80 on the developing gut microbiota in infants aged 0-6 months. Gut microbiota structure will be analyzed following shotgun sequencing, including strain presence and persistence in the infant's gut during 0-6 months of age.

Secondary Objectives

  1. To evaluate the impact of supplementation infant growth. Growth will be monitored by recording infant weight, length, and head circumference following the probiotic intervention.
  2. To evaluate the safety of the probiotics and the incidence rate of allergies and abdominal disturbances (eczema, skin itching, bloating/abdominal distension, diarrhoea).
  3. To detect human beta-defensin 2 (HBD-2) and Human Antimicrobial Peptide LL-37 (LL-37) in the faecal samples which aims to evaluate the impact of the two probiotic strains on the immune health of the infants following the probiotic intervention.
  4. To detect the levels of short-chain fatty acids (SCFAs) in the faecal samples following the probiotic intervention.

Study Type

Interventional

Enrollment (Estimated)

300

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 Locations

  • Ireland
      • Cork, Ireland
        • University College Cork
        • Contact:

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

  • Child

Accepts Healthy Volunteers

Yes

Description

Inclusion criteria Written (electronic) informed consent provided by parent to allow their infant to participate in the study.

No antibiotic use since birth. Infant not to be taking any medications. Infant not to be taking probiotics. Breastfed or formula fed until weaning. Infants born via c-section or vaginally. Healthy male and female infants.

Exclusion criteria Infant is older than 3 months at the time their first study visit (Baseline visit).

Infants who have a known diagnosis of inflammatory bowel disease or another medical condition.

Infants with complex medical or behavioural needs that would deem the infant unable to participate in the study.

Have a significant acute or chronic co-existing illness (cardiovascular, gastrointestinal, endocrinological, immunological, metabolic) or any condition which contraindicates entry to the study according to the investigator's judgement.

Infants who are receiving treatment involving experimental medications. Have a malignant disease or any concomitant end-stage organ disease. Infants born before 37 weeks of pregnancy.

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: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Placebo
Maltodextrin
Dietary supplement: Placebo (maltodextrin)
This study will investigate the effects of probiotics (Bifidobacterium animalis subsp. lactis BLa80 or Lacticaseibacillus rhamnosus LRa05), versus a placebo (maltodextrin), on the growth of infants and the development of their gut microbiota. The primary focus is on infant growth and gut microbiota development in infants aged 0-6 months. Maltodextrin is white, powdery, almost flavourless starch that is used to mimic the probiotic powder.
Experimental: Probiotic 1
BLa80
Dietary supplement: Probiotic
This study will investigate the effects of probiotics Bifidobacterium animalis subsp. lactis BLa80, versus a placebo (maltodextrin), on the growth of infants and the development of their gut microbiota. The primary focus is on infant growth and gut microbiota development in infants aged 0-6 months.
Dietary supplement: Probiotic
This study will investigate the effects of probiotic Lacticaseibacillus rhamnosus LRa05, versus a placebo (maltodextrin), on the growth of infants and the development of their gut microbiota. The primary focus is on infant growth and gut microbiota development in infants aged 0-6 months.
Experimental: Probiotic 2
LRa05
Dietary supplement: Probiotic
This study will investigate the effects of probiotics Bifidobacterium animalis subsp. lactis BLa80, versus a placebo (maltodextrin), on the growth of infants and the development of their gut microbiota. The primary focus is on infant growth and gut microbiota development in infants aged 0-6 months.
Dietary supplement: Probiotic
This study will investigate the effects of probiotic Lacticaseibacillus rhamnosus LRa05, versus a placebo (maltodextrin), on the growth of infants and the development of their gut microbiota. The primary focus is on infant growth and gut microbiota development in infants aged 0-6 months.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Primary Objective
Time Frame: 18 months
The primary aim is to describe the impact of supplementation with the probiotics LRa05 and BLa80 on the developing gut microbiota in infants aged 0-6 months. Gut microbiota structure will be analyzed following shotgun sequencing, including strain presence and persistence in the infant's gut during 0-6 months of age.
18 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Secondary Outcome Measure - Infant length
Time Frame: 18 months
To evaluate the impact of supplementation infant length. Length will be monitored by recording infant length (in cm) following the probiotic intervention.
18 months
Secondary Outcome Measure - Infant Weight
Time Frame: 18 months
To evaluate the impact of supplementation infant weight. Weight will be monitored by recording infant weight (in kg) following the probiotic intervention.
18 months
Secondary Outcome Measure - Head circumference
Time Frame: 18 months
To evaluate the impact of supplementation infant head circumference. Head circumference will be monitored by recording infant head circumference (in cm) following the probiotic intervention.
18 months
Secondary Outcome Measure - SCFA Analysis
Time Frame: 18 months
To detect the levels of short-chain fatty acids (SCFAs) in the faecal samples following the probiotic intervention.
18 months
Secondary Outcome Measure - Peptide Analysis (HBD-2)
Time Frame: 18 months
To detect human beta-defensin 2 (HBD-2) in the faecal samples which aims to evaluate the impact of the two probiotic strains on the immune health of the infants following the probiotic intervention.
18 months
Secondary Outcome Measure - Peptide Analysis (LL-37)
Time Frame: 18 months
To detect Human Antimicrobial Peptide LL-37 (LL-37) in the faecal samples which aims to evaluate the impact of the two probiotic strains on the immune health of the infants following the probiotic intervention.
18 months
Secondary Outcome Measure - Food Allergy Assessment (Eczema)
Time Frame: 18 months
To evaluate the safety of the probiotics and the incidence rate of skin allergies (eczema).
18 months
Secondary Outcome Measure - Food Allergy Assessment (Diarrhea)
Time Frame: 18 months
To evaluate the safety of the probiotics and the incidence rate of abdominal disturbances such as diarrheal episodes.
18 months

Collaborators and Investigators

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

Sponsor

University College Cork

Collaborators

Irish Centre for Fetal and Neonatal Translational Research
APC Microbiome Ireland, UCC

Investigators

  • Principal Investigator: Eugene M Dempsey, FRCPI, University College Cork

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)

April 1, 2026

Primary Completion (Estimated)

October 1, 2027

Study Completion (Estimated)

March 1, 2028

Study Registration Dates

First Submitted

March 2, 2026

First Submitted That Met QC Criteria

March 26, 2026

First Posted (Actual)

April 1, 2026

Study Record Updates

Last Update Posted (Actual)

April 1, 2026

Last Update Submitted That Met QC Criteria

March 26, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • APC198

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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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