Oral administration of Lactobacillus strains isolated from breast milk as an alternative for the treatment of infectious mastitis during lactation

Abstract

In this study, 20 women with staphylococcal mastitis were randomly divided in two groups. Those in the probiotic group daily ingested 10 log(10) CFU of Lactobacillus salivarius CECT5713 and the same quantity of Lactobacillus gasseri CECT5714 for 4 weeks, while those in the control one only ingested the excipient. Both lactobacillus strains were originally isolated from breast milk. On day 0, the mean staphylococcal counts in the probiotic and control groups were similar (4.74 and 4.81 log(10) CFU/ml, respectively), but lactobacilli could not be detected. On day 30, the mean staphylococcal count in the probiotic group (2.96 log(10) CFU/ml) was lower than that of the control group (4.79 log(10) CFU/ml). L. salivarius CECT5713 and L. gasseri CECT5714 were isolated from the milk samples of 6 of the 10 women of the probiotic group. At day 14, no clinical signs of mastitis were observed in the women assigned to the probiotic group, but mastitis persisted throughout the study period in the control group women. In conclusion, L. salivarius CECT5713 and L. gasseri CECT5714 appear to be an efficient alternative for the treatment of lactational infectious mastitis during lactation.

FIG. 1.

Staphylococcal counts in the milk samples obtained from women of the control (A) and probiotic (B) groups at days 0 and 30. The black bars (and the associated number) indicate the mean of the values.

FIG. 2.

Mammary areola of one of the probiotic group women at day 0, in which redness and a nipple crack are clearly visible (A) and at day 14 show a normal appearance (B).

FIG. 3.

Colony hybridization analysis of isolates obtained from the milk sample of woman 1 (probiotic group) at day 30 using either an L. salivarius-specific (A) or an L. gasseri-specific probe (B). (A) Spots: 1, L. gasseri CECT5714; 3, L. salivarius CECT5713; 5, 6, 7, and 8, positive isolates belonging to the species L. salivarius; 2, 4, 9, and 10, negative isolates that were identified as Staphylococcus spp. (B) Spots: 1, L. salivarius CECT5713; 3, L. gasseri CECT5714; 5, 7, and 10, positive isolates belonging to the species L. gasseri; 2, 4, 6, 8, and 9, negative isolates (Staphylococcus spp.).

FIG. 4.

PFGE patterns of SmaI-digested genomic DNA from L. salivarius CECT5713 (lane 1), six milk isolates that hybridized with the L salivarius probe in the colony hybridization assay (lanes 2 to 7), L. gasseri CECT5714 (lane 8), and three milk isolates that hybridized with the L. gasseri probe in the hybridization assay (lanes 9 to 11). L and M represent the standards LowRange PFG and MidRange PFG, respectively.