This study evaluates the effect of different complementary foods on the gastrointestinal microbiota of exclusively human milk fed infants.

The introduction of solid foods plays a role in shaping the microbial communities of the gastrointestinal microbiota. This randomized, controlled, single-blinded trial will evaluate the effect of four infant foods (oatmeal cereal, carrot puree, prune puree, beef and gravy puree) on the gastrointestinal microbiota of exclusively human milk fed infants that have not previously consumed solid foods and who are developmentally ready for the introduction of solid foods.

Inclusion Criteria:

• Infant was born vaginally
• Infant was born full term
• Infant has no significant gastrointestinal medical issues/diagnoses (e.g., gastroesophageal reflux, malabsorption syndromes, Celiac disease, Crohn's disease, or physician diagnosed or suspected food allergies)
• Infant is at least 5 months old, but not 8 or more months old
• Infant consumes an exclusively human milk liquid diet only
• Infant has not yet begun consuming solid foods
• Infant is developmentally ready to begin consuming solid foods (i.e., has good head and neck control, can sit upright when supported, and has at least doubled their birth weight)
• Infant has not had antibiotics within the past month
• Infant's nursing mother has not had antibiotics within the past month
• Parent/legal guardian is at least 18 years old

Exclusion Criteria:

• Infant is not developmentally ready to begin solid foods
• Infant has a family history of food allergy