Nosocomial infection with antibiotic-resistant strains is a major threat to critical care medicine. Selective decontamination of the digestive tract (SDD) is one of the strategies to reduce ventilator associated pneumonia and sepsis in critically ill patients. Lactoferrin (LF) is a natural multifunctional protein with antimicrobial, anti-tumor, antioxidant, and immunomodulatory effects. It has been shown to inhibit the growth of a number of pathogenic bacteria including antibiotic-resistant strains, fungi and even viruses in both in vitro and in vivo studies.