Children ( aged @-@years ) prescribed antibiotics , were randomised to receive @g/day of either yogurt ( probiotic ) containing Lactobacillus rhamnosus GG ( LGG ) , Bifidobacterium lactis ( Bb-@ ) and Lactobacillus acidophilus ( La-@ ) or a pasteurised yogurt ( placebo ) for the same duration as their antibiotic treatment .