This study evaluates the early infant feeding in the infant intestinal microecology and the long term health. 300 healthy term newborns were involved into the study on its first stage. Depending on the type of feeding the infants were divided into 3 groups with random allocation to one of the formula feeding groups: the group A included 100 infants consuming the formula supplement with superior quality whey protein, the group B -100 infants fed with a standard formula, and the group C -100 infants who were breastfed.

Throughout the human lifetime, the intestinal microbiota performs vital functions, such as barrier function, metabolic reactions, trophic effects, and maturation of the host's innate and adaptive immune responses. Therefore, the human health depends on the gut health. It is reported that the human gut microbiota of a healthy adult is highly resilient and very stable over time. And before it reaches maturity, the microbiota must develop itself from birth and establish its mutually beneficial cohabitation with the host. However, the early developments of the microbiota in infants are influenced by many factors, such as prenatal parameters, the influence of the mother and her microbiota, and therapies occurring around the time of birth.

Human milk is the sole source of nutrition for infants during the first weeks to months after birth, and has evolved to provide nutrition and immunological protection in the extra-uterine environment into which the infant is born. But when breastfeeding is not possible, human newborns may circumstantially be fed with infant formulas. The difference of feeding mode has been demonstrated to have a strong influence on early gut colonization particularly on the probiotic bacteria. Studies show that breastfed infants have higher counts of Bifidobacteria and Lactobacillus and lower counts of Bacteroides, Clostridium, coccoides group, Staphylococcus, and Enterobacteriaceae as compared with formula-fed infants.

Inclusion Criteria:

• Healthy term newborns (the mean gestational age in weeks > 36.0) with birth weight ≥2500 g appropriate for gestational age
• Apgar scores > 7
• Uncomplicated early course of neonatal period
• Impossibility of breastfeeding (for infants randomized into the bottle-feeding groups)

Exclusion Criteria:

• The minimum possibility of breastfeeding (for infants randomized into the bottle-feeding groups)
• The diagnosis of a significant chronic medical condition including: HIV infection; cancer; bone marrow or organ transplantation; blood product administration within the last 3 mo; bleeding disorder; known congenital malformation or genetic disorder
• If the parent or legal guardian were unable to read and/or comprehend Chinese
• If the family moved outside of Beijing during the study period (i.e., would be unavailable for follow-up)