Effect of Probiotics on Infant's Fecal Microbiota Composition

Double-blind, randomized, placebo-controlled clinical trial to determine the effect of the probiotic strains Bifidobacterium longum and Pediococcus pentosaceus on fecal microbiota composition in infants. Healthy babies with ages comprised between 60 and 90 days who meet inclusion and exclusion criteria will be randomized 1:1:1 to one of the following study groups: one group will receive Bifidobacterium longum, another group will receive Pediococcus pentosaceus and the other one will receive placebo for 3 months. Other study outcomes comprise anthropometric growth, frequency and consistency of the stools, digestive tolerance, wellbeing, number, type and duration of infections and functional gastrointestinal disorders, and adverse events.

Inclusion criteria

• Healthy infants
• Age between 1 and 90 days
• Gestational age between 37 and 42 weeks
• Appropiate birth weight for gestational age (between P10 and P90)
• APGAR test score for birth normal at 1' and 5' of 7-10
• Whose parents accept the follow-up of the study procedures and sign the informed consent

Exclusion criteria

• Infants participating in other clinical study
• Fed with infant formula containing probiotics or other aliments or food supplement based in probiotics 4 weeks prior the start of the study
• Infants who have taken antibiotics 4 weeks prior the start study
• Infants with cow's milk protein allergy, lactose intolerance or other digestive diseases
• Mother's pathological background and during gestation: neurologic disorders, matabolopaties, diabetes mellitus type 1, chronic disease (hypothyroidism), maternal malnutrition
• Acute congenital or acquired diseases which can interfere with the growth and the normal feeding of the infant
• TORCH complex infections
• Every other diseases related with the immune system
• Parents who can not accomplish the follow-up of the study (medical criterium)