Methods are provided for extracting and purifying maternal antibodies from breastmilk, followed by further processing to facilitate oral ingestion. The methods may be used on breastmilk from any mammal, including humans, for consumption by mammals including humans. Antibodies are well-known immune mediators that are naturally found in abundant supply in breastmilk, and they are passed directly to the offspring via breastfeeding. The methods described herein extract antibodies from breastmilk in a manner that preserves the structure and antigen-specificity while enabling the formulation into products that are optimized for delivery to mammals, including humans. The method comprises (1) breastmilk collection, (2) extraction of antibodies, (3) characterization of antibody structure, degradation, and contamination, and (4) formulation into a dietary supplement (food product) for delivery to mammals, especially humans.