To evaluate the effect of the consumption of Lactobacillus fermentum CECT5716 on mastitis incidence.

Previous studies have demonstrated that L. fermentum CECT5716, a probiotic strain previously isolated from breast milk, can be used as an effective treatment of mastitis and painful breastfeeding by reducing pathogen counts in breast milk. This is a randomized double blinded controlled study to evaluate the effect of L.fermentum CECT5716 on mastitis incidence and Staphylococcus load in breast milk. Women will be recruited 1-6 days after child birth and distributed into two groups: Probiotic group receiving 1 capsule/day containing L.fermentum 3x109cfu; Control group receiving 1 placebo capsule/day containing maltodextrin. The intervention period is 16 weeks.

Inclusion Criteria:

• Healthy women between 18 and 40 years with development of normal pregnancy Birth between 37 and 42 weeks of gestation. Women who have received antibiotic treatment between 48 hours before and 48 hours after childbirth (one dose is sufficient for inclusion regardless of the type of antibiotic).

Childbirth took place 1-7 days prior to recruitment.. With firm intention to breast-feed their children for at least 16 weeks..

Exclusion Criteria:

• - Mammary pathologies that hinder or preclude breastfeeding.
• Low expectation of adherence to the study protocol.