Low-protein Infant Formula With Partial or Extensive Proteinhydrolysate 4 Year Follow-up

Inclusion Criteria: * written informed consent (by parents, caregiver) * Healthy term newborns (gestational age: ≥ 37 weeks) * Birth weight between 2.500 - 4.500 g * Age at enrolment: \< 28 days of age * Infant received no other formula since birth * Parents / Caregivers are able to speak German Exclusion Criteria: * Severe acquired or congenital illness * preterm infants (gestational age \< 37 weeks) * Birth weight lower than 2.500 g or higher than 4.500 g * Feeding a cows milk based formula or any other formula prior to inclusion in this study * Participation in any other clinical study intervention * Regular intake of supplementary pre- and probiotics by the child and/or breastfeeding mother * Mothers with diabetes mellitus or mothers suffered from gestational diabetes * Founded assumption that it will not be possible for parents / caregivers to be compliant with the study protocol * Breastfed infants: illness of the mother, that may have an influence on the gastrointestinal tract of the child * Breastfed infants: mother receives or received antibiotics one week before inclusion in this study or during the first study phase