Colonisation Resistance Study

Inclusion Criteria: * Healthy term infants (gestational age 37 to 42 weeks) aged 2-2.5 months at inclusion * Fully formula fed for at least one week (not applicable for the breastfeeding reference group since these infants must be exclusively breastfed before and throughout the study) * Parents' or guardian's written informed consent Exclusion Criteria: * Being weaned before inclusion (introduction of any other foods other than formula or breast milk.) * Moderate or severe acute malnutrition, defined as weight-for-age and sex below -2 z-scores of the median WHO growth standards * Disorders requiring a special diet (such as food intolerance or food allergy or complaints such as reflux, constipation and cramps) * Significant congenital abnormality that could affect the study results * Use of systemic antibiotics or anti-mycotic drugs in the 4 weeks preceding the study * Investigator's uncertainty about the willingness or ability of the parents to comply with the protocol requirements * Participation in any other studies involving investigational or marketed products concomitantly or within two weeks prior to entry into the study * Gastroenteritis in the last two weeks before inclusion