Slow enrolment

This clinical trial will compare stool and oral microbiome composition between infants fed breast milk or one of two infant formulas for a 60 day feeding period.

Inclusion Criteria:

• 7-18 days of age at Visit 1
• Singleton birth
• Gestational age of 37-42 weeks
• Birth weight of 2500 g (5 lbs 8 oz) or more
• Parent or legal guardian agrees not to enroll infant in another interventional clinical study while participating in this study
• Signed informed consent and use of PHI for infant and birth mother
• Receipt of three protocol-compliant Baseline stool samples

Infants receiving formula:

• Exclusively receiving infant formula for at least 24 hours prior to randomization
• Parent(s) or legal guardian has full intention to exclusively feed study formula during the study period

Infants receiving human milk:

• Mother has intention to exclusively provide mother's-own breast milk for the duration of the study

Exclusion Criteria:

• Caesarean delivery
• Infant consumption of donor milk prior to randomization/registration
• Maternal antibiotic use within 48 hours prior to or at time of delivery
• Maternal antibiotic use while providing mother's-own breast milk to infant
• Infant use of systemic antibiotics prior to randomization/registration
• Any signs of an acute infection (i.e. fever, diarrhea) at randomization/registration
• Weight at Visit 1 is <95% of birth weight
• Infant use of probiotics
• Evidence of significant feeding difficulties
• Infant was born large for gestational age
• History of underlying metabolic or chronic disease or congenital malformation
• Infant is immunocompromised

Infants receiving human milk:

• Consumption of infant formula from 1 day of age