Protective effect of human lactoferrin in the gastrointestinal tract.

OBJECTIVE To describe mechanisms of action of human lactoferrin to protect gastrointestinal morbidities. DATA SOURCES Nonsystematic literature review using the following databases: SciELO, Lilacs and Medline from 1990 to 2011. The key-words used were lactoferrin, human milk/breastfeeding, gastrointestinal, and immunity, in Portuguese and English. DATA SYNTHESIS Lactoferrin is the second predominant protein in the human milk, with higher concentrations in the colostrum (5.0 to 6.7mg/mL) if compared to mature milk (0.2 to 2.6mg/mL.) In contrast, cow's milk has lower levels, with 0.83mg/mL in the colostrum and 0.09mg/mL in the mature milk. Lactoferrin has several physiological functions to protect the gastrointestinal tract. The antimicrobial activity is related to the ability to sequester iron from biological fluids and/or to destruct the membrane of microorganisms. Lactoferrin also has the ability to stimulate cell proliferation. The anti-inflammatory action exercised by lactoferrin is associated with its ability to penetrate the core of the leukocyte and to block the Kappa B nuclear factor transcription. Given the importance of lactoferrin to prevent infectious diseases for breastfed children, the industry is using genetic engineering techniques to develop the expression of recombinant human lactoferrin in animals and plants, attempting to adjust the composition of infant formulas to that of human milk. CONCLUSIONS Human lactoferrin is a peptide with great potential for preventing morbidity, especially in the gastrointestinal tract. Scientific evidence of the protective effects of human lactoferrin strengthens even more the recommendation for breastfeeding.