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.

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.

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.