Milk Oriented Microbiota

Inclusion Criteria: * Women with infants age 8 to 12 weeks * Term infants born \>37 weeks gestation * Mother-infant pairs who live within a 20-mile radius from UC Davis campus in Davis, CA or within a 20-mile UCDMC * Women and infants who live in one location * Infants born vaginally * Infants who are either exclusively formula-fed, exclusively breastfed or mixed-fed * Women who are mixed and formula feeding their infants who are willing to switch infant formulas and use the study's infant formula (Earth's Best Organic Infant Formula With Iron, Earth's Best) throughout the first two months of the study * Women who are breastfeeding but introduce infant formula to their infants during the first two months of the study who are willing to use the study's infant formula (Earth's Best Organic Infant Formula With Iron, Earth's Best) for the first two months of the study Exclusion Criteria: * Women who have lived in the United States or other developed nation for less than 10 consecutive years * Multiple infants born to one mother * Plan to feed infants solid foods before infants turn 5 months of age * Family history of cow milk or soy allergy and/or infants allergic to cow milk protein or soy * Infants born by C-section * Infants born with medical complications such as: respiratory distress syndrome, birth defects, and infection * Infants who have taken antibiotics 4 weeks before enrollment and more than one course of antibiotics since birth * Infants who have taken probiotics s…