This is a randomized placebo-controlled study that aims to investigate the effect of a new maternal dietary supplement (protein hydrolysate/yeast beta-glucan combination) on mother and infant health.

N=140 healthy pregnant multiparous females aged between 18-49 years will be recruited to the study during pregnancy or up to 4-weeks postpartum, n=70 consuming the supplement and n=70 consuming a placebo. Following successful recruitment and screening, researchers will complete 2 study visits at the participant's home. Visit 1 marks the start of the intervention period and Visit 2 marks the end of the intervention period.

Once the baseline data is completed (visit 1), the capsules will be provided to the mother. One capsule will be taken daily for 4 weeks. Capsules will be provided in convenient weekly tablet boxes. The return of used tablet boxes and counting missing capsules will monitor compliance. In addition, regular weekly contact will be maintained by phone and text message with participants to encourage adherence. In addition to the 2 study visits, all participants will receive an individual consultation with a lactation consultant to ensure breastfeeding techniques are appropriate and not a confounding factor in the breastmilk supply.

Data collection will include:

Anthropometric measurements include weight, height/length, and circumferences. Questionnaires will be used to collect birth data, demographic, lifestyle, breastfeeding and infant behavior, socio-economic status, health history, and gut health information.

Dietary intakes will be assessed using an online 24-hour recall tool. Blood samples will be collected from mothers by a trained phlebotomist. A 5mL aliquot of breast milk will be collected from a full breast milk expression in the 24 hours prior to the research nurse visit using an electric breast pump. Mothers will record the volume of milk expressed and the remainder will be stored by the mother for the infant. for will use an electric breast pump for a full breast expression. The aliquot will be refrigerated until the research nurse visit.

Mothers will collect a fecal sample from themselves and a fecal and urine sample from their baby in the 24 hours prior to the visit and will be stored in the freezer until the research nurse visit.

Inclusion Criteria:

• Postpartum women aged 18-49 years
• Multiparous with one previously breastfed child (defined as breastfed for greater than or equal to 3 months, does not need to be exclusively breastfed)
• Delivered term
• Woman free of breast or nipple infections
• Woman willing to avoid other galactagogues/breastmilk supply stimulants while on study
• Woman not taking medications that will affect lactation
• Woman is the established carer for the infant
• Infant has no baseline abnormality.

Exclusion Criteria:

• Less than 18 years old or older than 49 years (at time of recruitment)
• Smokers
• Individuals that are not free-living e.g. institutes where meals are prepared in bulk such as nursing homes, prisons etc.
• An inability to read, write or understand English
• Following a strict prescribed diet for any reason; insulin dependent diabetes, coeliac disease, Crohn's disease etc. as this may result in an altered gastrointestinal function.
• Mother or child has a milk protein allergy
• Covid-19 at very high-risk group (defined by HSE)

At the start of the study each participant will have a study code assigned to them. All of the data from the trials will be stored using these unique study codes. A file will be set up which will be stored in a location separate to the study data. This file will contain a list which will link each participants contact details to the corresponding ID code. All stored information will be encrypted and protected by a password that only the researcher and PI will know.

Double-blinded parallel study