This study will evaluate the incidence of allergic manifestations (the first of which is atopic dermatitis) and infectious diseases in children fed with an infant formula under real conditions of use.

The primary objective of the study is to evaluate the cumulative incidence of atopic dermatitis in healthy infants at risk for dysbiosis at 12 months of age and to identify factors associated with the presence of atopic dermatitis.

Inclusion Criteria:

• full-term infant (gestational age ≥ 37 and ≤ 42 weeks) in good health;

• Having at least one risk factor for dysbiosis, including:

  • birth by caesarean section,
  • Antibiotic exposure between birth and inclusion or in utero (mother who received antibiotics) during the last trimester of pregnancy, or per-partum (mother who received antibiotics during childbirth),
  • a family history of allergy confirmed by a doctor in a family member, affecting at least one of the two parents or siblings (asthma, atopic dermatitis, eczema, allergic rhinitis, proven food allergy);

• Aged at most 5 weeks;

• Having a weight in the reference values for gestational age and sex (between the 10th and the 90th percentiles according to the growth curves in force);

• Already consuming an infant formula (with or without associated breast milk), or whose mother wishes to introduce an infant formula at the end of this consultation to switch to mixed breastfeeding or to start weaning;

• Authorization of a parent (or both) or legal representative of the child to collect personal information about their child and family.

Exclusion Criteria:

• Premature infants or low birth weight (< 2500g);
• Infant allergic to cow's milk protein;
• Infants with severe congenital anomalies that may impact growth (cystic fibrosis, bronchopulmonary dysplasia, tracheomalacia, tracheoesophageal fistula, congenital heart defects ...);
• Infants with chronic disease or severe neonatal pathology, or a pathology predisposing to infections (HIV, hepatitis B or C, autoimmune diabetes, immune deficiency, respiratory distress, sepsis, intraventricular hemorrhage, severe neonatal hepatitis, necrotizing enterocolitis, hypertension persistent pulmonary ...), or renal or hepatic pathology;
• Inability of the parent or legal representative to understand the protocol of the study, or doubts of the physician on the ability or willingness to comply with the protocol.

Infants up to 1 month + 1 week, in good health, at risk of dysbiosis