title: Lactobacilli and bifidobacteria in human breast milk: influence of antibiotherapy and other host and clinical factors.
abstract: OBJECTIVE
  The objective of this work was to study the lactobacilli and bifidobacteria population in human milk of healthy women, and to investigate the influence that several factors (including antibioteraphy during pregnancy and lactation, country and date of birth, delivery mode, or infant age) may exert on such population.
  
  
  METHODS
  A total of 160 women living in Germany or Austria provided the breast milk samples. Initially, 66 samples were randomly selected and cultured on MRS-Cys agar plates. Then, the presence of DNA from the genera Lactobacillus and Bifidobacterium, and from most of the Lactobacillus and Bifidobacterium species that were isolated, was assessed by qualitative polymerase chain reaction (PCR) using genus- and species-specific primers.
  
  
  RESULTS
  Lactobacilli and bifidobacteria could be isolated from the milk of 27 (40.91%) and 7 (10.61%), respectively, of the 66 cultured samples. On the contrary, Lactobacillus and Bifidobacterium sequences were detected by PCR in 108 (67.50%) and 41 (25.62%), respectively, of the 160 samples analyzed. The Lactobacillus species most frequently isolated and detected was L salivarius (35.00%), followed by L fermentum (25.00%) and L gasseri (21.88%), whereas B breve (13.75%) was the bifidobacterial species most commonly recovered and whose DNA was most regularly found. The number of lactobacilli- or bifidobacteria-positive samples was significantly lower in women who had received antibiotherapy during pregnancy or lactation.
  
  
  CONCLUSIONS
  Our results suggest that either the presence of lactobacilli and/or bifidobacteria or their DNA may constitute good markers of a healthy human milk microbiota that has not been altered by the use of antibiotics.
authors.affiliation: *Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Universidad Complutense de Madrid, Madrid †Probisearch, Tres Cantos, Spain ‡Department of Nutritional Science, HiPP GmbH & Co. Vertrieb KG, Pfaffenhofen, Germany.
authors.forename: Ana
authors.initials: A
authors.lastname: Soto
authors.forename: Virginia
authors.initials: V
authors.lastname: Martín
authors.forename: Esther
authors.initials: E
authors.lastname: Jiménez
authors.forename: Isabelle
authors.initials: I
authors.lastname: Mader
authors.forename: Juan M
authors.initials: JM
authors.lastname: Rodríguez
authors.forename: Leonides
authors.initials: L
authors.lastname: Fernández
mesh_terms: D000328:Adult; D000773:Anesthesia, Obstetrical; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001317:Austria; D001644:Bifidobacterium / Q000235:genetics / Q000302:isolation & purification*; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000032:analysis*; D036861:Delivery, Obstetric; D005260:Female; D005858:Germany; D006801:Humans; D007774:Lactation; D007778:Lactobacillus / Q000235:genetics / Q000302:isolation & purification*; D008895:Milk, Human / Q000737:chemistry / Q000166:cytology / Q000382:microbiology*; D011247:Pregnancy
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial