Compare the HMO composition in breast milk of infants with allergic manifestation (atopic dermatitis and food allergy) in the first 3 years of life, healthy infants with allergic mother and healthy infants with non-allergic mother.

• Parents of breast-fed infant from general pediatric clinic and allergy clinic of King Chulalongkorn Memorial Hospital were approached for informed about the research and ask to join this project
• After completed informed consent, demographic data was collected and filled in case record form
• Milk of mother in both allergic and control groups were collected 60 ml then transferred to freeze at -80oc to for human milk oligosaccharide analysis

Inclusion Criteria:

1. mothers with breast-fed infant with or without allergic manifestation
2. Intend to participate for follow up and sign consent to participate in the study

Exclusion Criteria:

1. Mothers with any medical illness or high risk infant pregnant
2. Infants with disease which affected allergic disease
3. No inform consent
4. Anything in the opinion of the investigator that would prevent children from completing the study

Normal term children (born after 37 weeks gestation) from low risk healthy pregnant women aged 18-40 years divided to 3 groups i. Allergic groups : infants with allergic manifestation ii. High risk control groups : atopic mother with infant no disease iii. Healthy control groups : non- atopic mother with infant no disease