Inclusion Criteria:
1. Evidence of personally signed and dated informed consent document indicating that at least one of the infant's parent(s)/LAR(s), as per local regulation, have been informed of all pertinent aspects of the study.
2. Infants whose parent(s)/LAR(s) have reached the legal age of majority in the countries where the study is conducted.
3. Able to temporarily store stool samples in a household freezer.
4. Infants whose parent(s)/LAR(s) are willing and able to comply with scheduled visits, and the requirements of the study protocol.
5. Infants whose parent(s)/LAR(s) are able to be contacted directly by telephone throughout the study.
6. Infants must meet all of the following inclusion criteria to be eligible for enrollment into the study:
1. Healthy term infant (≥37 weeks of gestation).
2. At enrollment visit, post-natal age ≥14 to ≤35 days / 0.75 - 1 month (date of birth = day 0)
3. Birth weight ≥ 2500g and ≤ 4500g.
4. For formula-fed groups, infants must be exclusively consuming and tolerating a cow's milk infant formula at time of enrollment and their parent(s)/LAR(s) must have independently elected, before enrollment, not to breastfeed.
5. For the breastfed group, infants must have been exclusively consuming breastmilk since birth (small amounts of other feedings allowed during the first three days of life before breastfeeding is well-established), and their parent(s)/LAR(s) must have made the decision to continue exclusively breastfeeding until at least 4 months of age.
Exclusion Criteria:
1. Infants with conditions requiring infant feedings other than those specified in the protocol.
2. Infants who have a medical condition or history that could increase the risk associated with study participation or interfere with the interpretation of study results, including:
1. Evidence of major congenital malformations (e.g., cleft palate, extremity malformation).
2. Suspected or documented systemic or congenital infections (e.g., human immunodeficiency virus, cytomegalovirus, syphilis).
3. Previous or ongoing severe medical or laboratory abnormality (acute or chronic) which, in the judgment of the investigator, would make the infant inappropriate for entry into the study. Of note, children who are normally healthy but at the time of enrolment suffering from acute illness in a minor condition which are common in childhood and do not require some of the exclusionary medication mentioned below can be enrolled.
3. Infants who are presently receiving or have received prior to enrolment any of the following: medication(s) or supplement(s) which are known or suspected to affect the following: fat digestion, absorption, and/or metabolism (e.g., pancreatic enzymes); stool microbiota and characteristics (e.g., oral, or systemic antibiotics, glycerin suppositories, bismuth-containing medications, docusate, Maltsupex, or lactulose); growth (e.g., insulin or growth hormone); gastric acid secretion.
4. Currently participating or having participated in another interventional clinical trial since birth.
