title: Development of intestinal bifidobacteria and lactobacilli in breast-fed neonates.
abstract: OBJECTIVE
  Neonates are subject to numerous factors that affect normal intestinal colonization. This study was to quantify bifidobacteria and lactobacilli in the faeces of breast-fed neonates using quantitative real-time PCR assay, and to investigate the effects of different delivery on the development of bifidobacteria or lactobacilli.
  
  
  METHODS
  The faecal bifidobacteria and lactobacilli of 40 healthy breast-fed neonates were studied prospectively. Twenty infants were vaginally delivered (VD), and 20 by caesarean delivery (CD) with prophylactically 4 g intravenous cefradine administered to their mothers three times. The faecal bifidobacteria and lactobacilli of neonates were consecutively quantified by SYBR Green I-based real-time PCR assay in the first 7 days after birth.
  
  
  RESULTS
  The mean levels of bifidobacteria increased from 5.1 to 9.3 in the VD group vs from less than 4.6 to 8.7 in the CD group. The bifidobacteria colonization levels in six samples in the CD group were lower than the limit of detection on day 2. The mean levels of bifidobacteria in the VD group were significantly higher than in the CD group (p<0.05). The mean levels of lactobacilli increased from 4.9 to 7.2 in the VD group vs from 4.9 to 6.9 in the CD group. There was no statistical difference between two groups during the first week (p>0.05). The development of bifidobacteria and lactobacilli showed significant interindividual differences in all infants studied.
  
  
  CONCLUSIONS
  Primary intestinal bifidobacteria in neonates by caesarean may be disturbed more significantly than lactobacilli.
authors.affiliation: Clinical Nutrition Center, Xin Hua Hospital, School of Medicine, Shanghai Jiaotong University, 1665 Kongjiang Road, Shanghai 200092, China. jjvoo1974@hotmail.com
authors.forename: Jinjin
authors.initials: J
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Cai
authors.forename: Yi
authors.initials: Y
authors.lastname: Feng
mesh_terms: D000328:Adult; D001644:Bifidobacterium / Q000254:growth & development* / Q000302:isolation & purification; D001942:Breast Feeding; D002585:Cesarean Section / Q000009:adverse effects / Q000379:methods; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000032:analysis; D036861:Delivery, Obstetric / Q000379:methods*; D005243:Feces / Q000382:microbiology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007422:Intestines / Q000382:microbiology; D007778:Lactobacillus / Q000254:growth & development* / Q000302:isolation & purification; D008297:Male; D016133:Polymerase Chain Reaction / Q000379:methods; D011247:Pregnancy; D011446:Prospective Studies
chemical_list: D004269:DNA, Bacterial