Peanut allergy is the most common cause of fatal and near-fatal food-allergic reactions and egg allergy is among the two most common causes of food-induced anaphylaxis. The proposed research will explore the development of sensitization to these food(s) in infants based on maternal consumption or avoidance during pregnancy and breastfeeding.

The goals of this study include defining the role of egg and peanut consumption or avoidance during pregnancy and via human milk in food sensitization and identifying the underlying biological mechanisms leading to sensitization or tolerance. The study population will include 500 mother/infant dyads who plan to exclusively feed breastmilk to healthy infants. We expect approximately 25% will be recruited locally and the rest from across the United States. This is a national, parallel, two arm, one-to-one allocation, single blinded, randomized controlled trial. Each arm of the study defines maternal diet from 27 weeks gestation through their baby's fourth month with some consuming peanut and egg and some avoiding these foods.

Inclusion Criteria:

• o Subject must be able to understand and provide informed consent.

• English-speaking adults, 18 years or older. (Spanish speaking adults may be included after consent document is translated and Spanish speaking study representatives are available to conduct and answer questions during informed consent process and for study follow up.)

• Maternal consent must be provided for infants.

• Pregnant women from the time pregnancy is confirmed until 27 weeks of gestation.

• Self-reported at time of enrollment:

  • no chronic inflammatory conditions that require long-term systemic immunosuppressive medications in first or second trimester
  • carrying a fetus with a first-degree relative (i.e., mother, father, full sibling) with any self-reported or physician-diagnosed allergic disease (asthma, allergic rhinitis, atopic dermatitis, or food allergy).

• Intend to give their infant their own breast milk for more than 3 months.

• Can confidently say they have eaten PN and egg and have tolerated consumption with no food allergy reactions.

• Willing to be randomized to consumption or avoidance diet.

• Uncomplicated pregnancy (no gestational diabetes, no preeclampsia, no hyperemesis gravidarum), self-reported at time of enrollment.

Exclusion Criteria:

• Inability or unwillingness of subject to give written informed consent or comply with study protocol.
• Known history of renal/liver/cardiac insufficiency in the mother or infant.
• Pregnant women with PN or egg allergy.
• Pregnant women who refuse to eat PN (or peanut products) and/or eggs.
• Physician diagnosed immunodeficiency in the mother or infant.
• Current, diagnosed, mental illness or current, diagnosed, or self-reported, drug or alcohol abuse that, in the opinion of the investigator, would interfere with the subject's ability to comply with study requirements.
• Past or current medical problems or findings from medical history that are not listed above, which, in the opinion of the investigator, may pose additional risks to the mother or infant from participation in the study, may interfere with the subject's ability to comply with study requirements or that may impact the quality or interpretation of the data obtained from the study.

To understand the mechanisms whereby maternal diet either positively or negatively affects the development of their infant from the womb through the first few months of life, it is necessary to recruit healthy pregnant women.

Per NIH policy

Due to the nature of the intervention, the subjects must know which arm they are assigned to, however, biostatistician and investigators will be blinded to study assignment.