The present invention relates to a novel process for the selection of new probiotic strains which comprises the following steps: a) selecting for non-pathogenic strains which are capable of surviving in breast milk and/or amniotic fluid, and b) selecting for non-pathogenic strains which are able to be transferred to breast milk and/or amniotic fluid after oral intake in healthy individuals without colonizing other internal organs except mucousas. The invention also provides new Lactobacillus strains, which are: CECT5711 (Lactobacillus coryniformis), CECT5713 (Lactobacillus salivarius subsp. salivarius), CECT5714: (Lactobacillus gasseri, formerly L. acidophilus), CETC5715: (Lactobacillus gasseri), and CECT5716: (Lactobacillus fermentum); and refers to their use for the prophylaxis or treatment against digestive, infective, neuro-degenerative and immune related diseases such as allergies or inflammatory diseases.