AIM:Many defense factors of the mother’s colostrum ormilk protect infants from intestinal,respiratory and systemicinfections.In the present study,we investigated the effectof colostrum and mature human milk on E.histolyticaparasites in vitro.METHODS:Samples of human milk were collected from 5healthy lactating mothers.The medium with human milk atconcentrations of 2%,5% and 10% was obtained.RESULTS:The lethal effect of E.histolytica on the mediumsupplemented with different concentrations of both colostrumand mature human milk was significant during the first30 min.We also detected that the results of colostrum andmature human milk were similar.No statistically significantdifferences were found between same concentrations ofcolostrum and mature human milk at the same times.CONCLUSION:Colostrum and mature human milk havesignificant lethal effect on E.histolytica and protect againstits infection in breast fed children. AIM: Many defense factors of the mother’s colostrum ormilk protect infants from intestinal, respiratory and systemic infections. In the present study, we investigated the effect of colostrum and mature human milk on E. histolytica parasites in vitro. METHODS: Samples of human milk were collected from 5 heathy lactating mothers.The medium with human milk at concentrations of 2%, 5% and 10% was obtained .RESULTS: The lethal effect of E.histolytica on the mediumsupplemented with different concentrations of both colostrumand mature human milk was significant during the first30 min.We also detected that the results of colostrum andmature human milk were similar. No significant significant differences were found between same concentrations of colostrum and mature human milk at the same times. CONCLUSION: Colostrum and mature human milk have ignificant lethal effect on E. histolytica and protect against infection in breast fed children.