LTF and digestive system infectious disorder: Accordingly, infant formula fortification with exogenous lactoferrin has been suggested for a long time [139], and a few clinical trials showed bovine lactoferrin supplementation’s effectiveness in preventing respiratory and intestinal infections in infants [139,140,141] as well as in preventing severe disease manifestations such as necrotizing enterocolitis (NEC) and sepsis in preterm infants [20,21,139,142].