A glycoprotein found in milk may prevent the transmission of HIV from mothers to their children. Lactoferrin is a natural antibiotic, secreted in a number of body fluids; including saliva, bile, pancreatic fluid, tears and milk. A team of Norwegian and US scientists led by Rolando Viani, of the University of California, San Diego, presented data that showed lactoferrin prevented the transmission of HIV in laboratory-grown human cell cultures.