IBCLC Practice Exam 2026 – All-in-One Guide to Excelling in Your Lactation Consultant Certification!

The correct response highlights the role of alpha-lactalbumin, which is a whey protein found in human milk. This protein plays an integral part in forming complexes with oleic acid in the infant gut. When oleic acid interacts with alpha-lactalbumin, it contributes to the immune protection offered to infants by enhancing the antibacterial and anticancer properties of the milk.

The combination of oleic acid and alpha-lactalbumin promotes the formation of bioactive compounds that can help in combating pathogens and might also exert some antitumoral effects. This relationship is particularly vital in early life as infants are very vulnerable to infections and other diseases, making the immune benefits from breast milk critical.

Other proteins mentioned, such as beta-lactoglobulin, casein, and lactoferrin, play important roles in nutrition and immunity as well, but they do not specifically form the same type of complex with oleic acid to the extent that it has significant antibacterial and anticancer activity. Therefore, the connection between oleic acid and alpha-lactalbumin is a key factor in understanding how breast milk supports an infant's immune system.