Probiotic Bacteria Isolated from Breast Milk for the Development of New Functional Foods

Abstract

Baby’s intestine is (or was said to be) sterile at birth and gut microbiota development is a gradual process after delivery. Quantitative and qualitative differences in bifidobacterial and lactic acid bacteria levels and species composition have been shown between breastfed and formula-fed infants, bifidobacteria being the most dominant microorganisms in the former group. Establishment of the gut microbiota is a stepwise process which provides the earliest and most massive source of microbial stimuli for the normal maturation of the gut mucosal immune system, contributing to its development in infancy and to the control of the gut-associated immunological homeostasis later in life. Probiotic intervention in the neonatal period has attracted scientific interest after recent demonstrations showing that specific strains reduce the symptoms and risk of allergic and infectious diseases or improve feeding tolerance. However, no all early interventions in children reported rendered positive results. The question of the right dose and the specific pathologies that probiotic administration, to infants less than 6 month of age, could be helpful for is still under a vigorous debate. Breast milk contains several factors, including nutrients, antimicrobial agents, IgA antibodies and TGF-β, which contribute beneficially to the immunologic maturation and well-being of the infant as well as factors that promote the growth of bifidobacteria in the infant’s intestine. Additionally, healthy breast milk contains significant numbers of bacteria. In 2003 it was reported the isolation of lactobacilli from breast milk as potential probiotics. Breast milk seems to be a natural source of probiotic bacteria for infants. In this context, supplementation of infant formulas with these kinds of probiotics might beneficially alter the composition of the microflora of formula-fed infants in such a way that it resembles that of breast-fed infants. However, to date there is no available information concerning the technological potential of these strains for their industrialization (growth in milk, resistance to lactic acid, freezing or spray-drying, among others) if they are thought to be included in dairy products or in formulas for infants.