Probiotic lactobacilli in faeces of breastfed babies

Abstract

Balanced colonization of the gastrointestinal tract in the newborn is very important for the acquisition of an immune system in infancy. Lactobacillus spp. is useful in human nutrition because of its potential probiotic and functional features. In this research, 27 strains were identified representing 104 species of Lactobacillus isolated from baby feces. The probiotic and functional properties of isolates were investigated. In this study, the sample consisted of 14 children aged 3-47 weeks who were breastfed. Strains were determined phenotypically by testing arginine hydrolysis, salt tolerance, production of gas from glucose, and growth at 15 and 45 degrees C. Isolated strains were genotypically characterized as Lactobacillus paracasei subsp. paracasei (41), L. casei (17), L. fermentum (24), Lactobacillus spp. (11), and L. rhamnosus (11) using 16S rDNA sequence analysis. Several strains of L. fermentum, and a majority of the strains of L. rhamnosus and L. casei/L. paracasei subsp. paracasei were able to produce hydrogen sulfide. Almost all strains showed antibacterial activity against the enteric pathogens Escherichia coli O157:H7, E. coli, Listeria monocytogenes, Staphylococcus aureus, and Salmonella Enteritidis. In this research, lactobacilli isolated from babies had probiotic properties.