title: Influence of Intrapartum Antibiotic Prophylaxis for Group B Streptococcus on Gut Microbiota in the First Month of Life.
abstract: OBJECTIVE
  The effect of intrapartum antibiotic prophylaxis (IAP) for group B Streptococcus (GBS) on bacterial colonization of the infant's gut has not been investigated extensively. We aimed to evaluate the effect of IAP on gut microbiota in healthy term infants, also exploring the influence of type of feeding.
  
  
  METHODS
  Healthy term infants, whose mothers had been screened for GBS in late gestation, were divided into 2 groups: infants born to GBS-positive mothers who had received IAP versus controls. Neonatal fecal samples were collected at 7 and 30 days of life; DNA was extracted, and quantification of selected microbial groups (Lactobacillus spp, Bifidobacterium spp, and Bacteroides fragilis group) was performed by real-time PCR.
  
  
  RESULTS
  A total of 84 infant-mother pairs were recruited. Bifidobacteria count was significantly lower in the IAP group at 7 days of life (median [interquartile range] 6.01 Log colony-forming unit per gram [5.51-6.98] vs 7.80 [6.61-8.26], P = 0.000). No differences in Bifidobacteria count at 30 days or in Lactobacilli and B fragilis counts at any time point were documented. Furthermore, at 7 days of life, infants who had not received IAP and were exclusively human milk-fed had higher counts of Bifidobacteria. Regardless of IAP treatment, infants fed exclusively human milk had higher Lactobacillus spp counts both at 7 and 30 days of life.
  
  
  CONCLUSIONS
  IAP alters gut microflora by reducing the count of Bifidobacteria, which is further affected in infants receiving formula feeding. Whether these alterations could have long-term consequences on health and disease requires further investigation.
authors.affiliation: *Department of Medical and Surgical Sciences, Neonatology and Neonatal Intensive Care, S. Orsola-Malpighi Hospital †Department of Agricultural Sciences, University of Bologna, Bologna, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Corvaglia
authors.forename: Giacomo
authors.initials: G
authors.lastname: Tonti
authors.forename: Silvia
authors.initials: S
authors.lastname: Martini
authors.forename: Arianna
authors.initials: A
authors.lastname: Aceti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Mazzola
authors.forename: Irene
authors.initials: I
authors.lastname: Aloisio
authors.forename: Diana
authors.initials: D
authors.lastname: Di Gioia
authors.forename: Giacomo
authors.initials: G
authors.lastname: Faldella
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000009:adverse effects* / Q000494:pharmacology; D019072:Antibiotic Prophylaxis; D001439:Bacteroides / Q000187:drug effects / Q000254:growth & development; D001644:Bifidobacterium / Q000187:drug effects* / Q000254:growth & development; D004269:DNA, Bacterial / Q000032:analysis; D005243:Feces / Q000382:microbiology; D005247:Feeding Behavior; D005260:Female; D000069196:Gastrointestinal Microbiome / Q000187:drug effects*; D041981:Gastrointestinal Tract / Q000382:microbiology; D006801:Humans; D007223:Infant; D041943:Infant Formula; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D007778:Lactobacillus / Q000187:drug effects* / Q000254:growth & development; D008297:Male; D008895:Milk, Human / Q000382:microbiology; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy; D060888:Real-Time Polymerase Chain Reaction; D012189:Retrospective Studies; D013290:Streptococcal Infections / Q000382:microbiology / Q000517:prevention & control* / Q000635:transmission; D013292:Streptococcus agalactiae / Q000254:growth & development
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial