Characterization of some potentially probiotic Lactobacillus strains of human origin

A novel preparation for human use was investigated for probiotic properties of new lactobacilli isolates from oral and fecal samples of children. Identified strains were Lactobacillus plantarum (Lac1, Lac2, Lac6, and Lac7), Lactobacillus casei (Lac3), and Lactobacillus paracasei (Lac4). Isolates were non-hemolytic, produced organic acids, were tolerant to wide ranges of temperature, NaCl, and pH, and were highly resistant to lysozyme, acidity, and bile salts. High survival rates in artificial gastric and intestinal fluids indicated abilities to survive passage through the gastrointestinal tract. Antimicrobial activities were restricted to bacteria, attributed to low pH values. Isolated strains possessed good aggregation abilities, high hydrophobicity values, and moderate abilities to adhere to HCT 116 cells. Substantial probiotic features were identified for all isolates. Lac2, Lac6, and Lac7 were identified as the most advantageous candidates for further study of other probiotic and technological properties.