title: Probiotic intervention in the first months of life: short-term effects on gastrointestinal symptoms and long-term effects on gut microbiota.
abstract: OBJECTIVE
  To determine whether probiotics administered for 6 months postnatally affect gastrointestinal symptoms, crying and the compositional development of the gut microbiota through infancy.
  
  
  METHODS
  The study comprised of 132 newborns whose mothers were randomized to receive placebo or Lactobacillus rhamnosus GG (ATCC 53103) before delivery. The treatments of mothers/infants continued for 6 months postnatally. A specific symptom chart was used to monitor gastrointestinal symptoms and infant's crying during the 7th and the 12th weeks of life. Fluorescent in situ hybridization was used to establish the Bifidobacterium, Lactobacillus/Enterococcus, Bacteroides and Clostridium counts in fecal samples at 6, 12, 18 and 24 months of age.
  
  
  RESULTS
  Numbers of different types of stools, vomits and crying time were comparable between the groups during the 7th and the 12th weeks of life. Dominant microbiota consisted of bifidobacteria throughout the study. At 6 months, there were less clostridia in faeces in the placebo compared with the probiotic group (P = 0.026), whereas after long-term follow-up at 2 years, there were less lactobacilli/enterococci and clostridia in faeces in the probiotic group than in the placebo group (P = 0.011 and P = 0.032, respectively), reflecting the impact of clostridia as a marker of microbiota succession in healthy infants.
  
  
  CONCLUSIONS
  Probiotic administration in the first months of life was well tolerated and did not significantly interfere with long-term composition or quantity of gut microbiota.
authors.affiliation: Department of Pediatrics, Turku University Central Hospital, Finland. minrin@utu.fi
authors.forename: Minna
authors.initials: M
authors.lastname: Rinne
authors.forename: Marko
authors.initials: M
authors.lastname: Kalliomäki
authors.forename: Seppo
authors.initials: S
authors.lastname: Salminen
authors.forename: Erika
authors.initials: E
authors.lastname: Isolauri
mesh_terms: D000328:Adult; D001644:Bifidobacterium / Q000254:growth & development / Q000302:isolation & purification; D003013:Clostridium / Q000254:growth & development / Q000302:isolation & purification; D015169:Colony Count, Microbial; D003448:Crying; D003968:Diarrhea, Infantile / Q000453:epidemiology / Q000382:microbiology; D016983:Enterococcus / Q000254:growth & development / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology*; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D007227:Infant Nutritional Physiological Phenomena; D007231:Infant, Newborn; D052201:Lacticaseibacillus rhamnosus / Q000254:growth & development* / Q000302:isolation & purification; D008297:Male; D011247:Pregnancy; D011295:Prenatal Care / Q000379:methods*; D019936:Probiotics; D013045:Species Specificity; D014839:Vomiting / Q000453:epidemiology