Mastitis and painful breastfeeding is associated with mammary bacterial dysbiosis, a process in which the population of potential pathogens increases at the expense of the normal mammary microbiota, among them, Staphylococcus has been considered the most common agent of mastitis.

In this article, Maldonado-Lobón and collaborators aimed to evaluate the efficiency of three different doses of Lactobacillus fermentum CECT5716 to reduce the load of Staphylococcus in the breastmilk of women suffering from painful breastfeeding not associated with acute mastitis.

Previous studies demonstrated that L. fermentum CECT5716, a probiotic strain isolated from breastmilk, is an effective treatment of mastitis by reducing pathogen counts in breastmilk. Here, the researchers carried out a randomized double-blinded controlled study to measure the presence of different bacteria (Staphylococcus, Streptococcus and Lactobacillus) in the breastmilk of mothers who experienced breast pain, in a double-blind, placebo-controlled human study. They gave L. fermentum CECT5716 to the mothers for three weeks, within four study groups; three groups received the probiotic strain at doses of 3×109 colony-forming units (CFU)/day, 6×109 CFU/day, or 9×109 CFU/day, and the fourth group received a placebo of maltodextrin. The results showed that the probiotic groups experienced a significant reduction in the concentration of Staphylococcus in breastmilk compared to controls, as well as a significant reduction in breast pain during lactation. Although no dose-response effect was observed, a significant difference in the pain score was observed among the groups receiving the three probiotic doses compared with the control group.

Thus, the authors concluded that L. fermentum CECT5716 is an efficient treatment for breast pain during lactation associated with a high level of Staphylococcus in breastmilk. However, the question about how a probiotic in the gut can act at a distant site like the breast remains to be understood.



Maldonado-Lobón JA, et al. (2015) Lactobacillus fermentum CECT 5716 Reduces Staphylococcus Load in the Breastmilk of Lactating Mothers Suffering Breast Pain: A Randomized Controlled Trial. Breastfeeding Medicine 10(9), pp. 425-432. doi:10.1089/bfm.2015.0070