title: Human milk is a source of lactic acid bacteria for the infant gut.
abstract: OBJECTIVE
  To investigate whether human breast milk contains potentially probiotic lactic acid bacteria, and therefore, whether it can be considered a synbiotic food. Study design Lactic acid bacteria were isolated from milk, mammary areola, and breast skin of eight healthy mothers and oral swabs and feces of their respective breast-fed infants. Some isolates (178 from each mother and newborn pair) were randomly selected and submitted to randomly amplified polymorphic DNA (RAPD) polymerase chain reaction analysis, and those that displayed identical RAPD patterns were identified by 16S rDNA sequencing.
  
  
  RESULTS
  Within each mother and newborn pair, some rod-shaped lactic acid bacteria isolated from mammary areola, breast milk, and infant oral swabs and feces displayed identical RAPD profiles. All of them, independently from the mother and child pair, were identified as Lactobacillus gasseri. Similarly, among coccoid lactic acid bacteria from these different sources, some shared an identical RAPD pattern and were identified as Enterococcus faecium. In contrast, none of the lactic acid bacteria isolated from breast skin shared RAPD profiles with lactic acid bacteria of the other sources.
  
  
  CONCLUSIONS
  Breast-feeding can be a significant source of lactic acid bacteria to the infant gut. Lactic acid bacteria present in milk may have an endogenous origin and may not be the result of contamination from the surrounding breast skin.
authors.affiliation: Departament of Nutrición y Bromatología III, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: Rocío
authors.initials: R
authors.lastname: Martín
authors.forename: Susana
authors.initials: S
authors.lastname: Langa
authors.forename: Carlota
authors.initials: C
authors.lastname: Reviriego
authors.forename: Esther
authors.initials: E
authors.lastname: Jimínez
authors.forename: María L
authors.initials: ML
authors.lastname: Marín
authors.forename: Jordi
authors.initials: J
authors.lastname: Xaus
authors.forename: Leonides
authors.initials: L
authors.lastname: Fernández
authors.forename: Juan M
authors.initials: JM
authors.lastname: Rodríguez
mesh_terms: D001940:Breast / Q000382:microbiology; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007422:Intestines / Q000382:microbiology*; D007778:Lactobacillus / Q000302:isolation & purification*; D008895:Milk, Human / Q000382:microbiology*; D009061:Mouth Mucosa / Q000382:microbiology; D019936:Probiotics / Q000302:isolation & purification*; D011897:Random Allocation; D012867:Skin / Q000382:microbiology; D014621:Vagina / Q000382:microbiology