LTF and infection: HM feeding promotes a healthy microbiome, supports appropriate maturation of the developing immune system [70], and protects infants against infections mainly via secretory IgA antibodies, as well as via immunomodulatory factors such as enzymes (lysozyme, lactoferrin, etc.), cytokines, complement system components, leukocytes, oligosaccharides, nucleotides, lipids, and hormones, which ensure host defence against infections and modulate the immune response [3].