Colostrum is the fluid that new mothers’ breasts produce during the first day or two after birth. It gives newborn infants a rich mixture of antibodies and growth factors that help them get a good start.
Although colostrum has been available since the first mammals walked the earth, it is relatively new as a nutritional supplement. The resurgence of breast-feeding in the 1970s sparked a revival of interest in colostrum for both infants and adults.
However, most commercial colostrum preparations come from cows, not humans.
The antibodies a mother cow gives to her calf are designed to fend off bacteria that are dangerous to cows; these may be very different from those that pose risks to humans. However, colostrum also contains substances that might offer general benefits, such as growth factors (which stimulate the growth and development of cells in the digestive tract and perhaps elsewhere) and transfer factor (which may have general immune-activating properties). While it isn’t 100% clear that the cow version of these substances is active in humans, it may be.
In addition, researchers working with colostrum from animal sources use a special technique to make it more useful for humans. They inoculate cows with bacteria and viruses that do affect humans. The cow in turn makes antibodies to them, and secretes those antibodies into its colostrum. Colostrum enriched in this way is called “hyperimmune colostrum,” and it has shown considerable promise as an infection-fighting agent.