title: Effects of feeding an infant formula containing Lactobacillus GG on the colonization of the intestine: a dose-response study in healthy infants.
abstract: OBJECTIVE
  This study aimed to determine whether feeding Lactobacillus GG (LGG) at varying levels (10 to 10 cfu/day) would result in colonization, defined as > or =1,000 cfu of LGG per gram of stool in 3 of 5 samples collected during the feeding period.
  
  
  METHODS
  Infants received unsupplemented formula during a 7-day baseline, 1 of 4 formulas containing 0 (control), 10 (low), 10 (medium), or 10 (high) cfu of LGG per day during a 2-week test, and unsupplemented formula during a 2-week follow-up. Baseline, test, and follow-up stool samples were evaluated for levels of viable LGG.
  
  
  RESULTS
  During test, supplemented infants were colonized, compared with control (P < 0.05). Median stool counts of LGG (log10 cfu/g) in colonized infants were 5.24 (low), 6.05 (medium), and 5.97 (high). LGG persisted in the stools for 7 to 14 days after discontinuing LGG. No differences were observed among groups in stool consistency, flatulence, fussiness, or adverse events.
  
  
  CONCLUSIONS
  A 2-week oral administration of 10 to 10 cfu/day LGG was well tolerated; all levels successfully colonized the intestinal tract of healthy, term infants.
authors.affiliation: Mead Johnson Nutritionals, Evansville, IN 47721, USA. bryon.petschow@bms.com
authors.forename: Bryon W
authors.initials: BW
authors.lastname: Petschow
authors.forename: Reinaldo
authors.initials: R
authors.lastname: Figueroa
authors.forename: Cheryl L
authors.initials: CL
authors.lastname: Harris
authors.forename: Laura B
authors.initials: LB
authors.lastname: Beck
authors.forename: Eckhard
authors.initials: E
authors.lastname: Ziegler
authors.forename: Barry
authors.initials: B
authors.lastname: Goldin
mesh_terms: D015169:Colony Count, Microbial; D004311:Double-Blind Method; D005243:Feces / Q000737:chemistry / Q000382:microbiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D041943:Infant Formula / Q000008:administration & dosage*; D007231:Infant, Newborn; D007422:Intestines / Q000382:microbiology*; D007778:Lactobacillus / Q000254:growth & development* / Q000302:isolation & purification; D008297:Male; D012016:Reference Values