title: Effect of Lactobacillus salivarius Ls-33 on fecal microbiota in obese adolescents.
abstract: OBJECTIVE
  This study is a part of the clinical trials with probiotic bacterium Lactobacillus salivarius Ls-33 conducted in obese adolescents. Previously reported clinical studies showed no effect of Ls-33 consumption on the metabolic syndrome in the subject group. The aim of the study was to investigate the impact of L. salivarius Ls-33 on fecal microbiota in obese adolescents.
  
  
  METHODS
  The study was a double-blinded intervention with 50 subjects randomized to intake of L. salivarius Ls-33 or placebo for 12 weeks. The fecal microbiota was assessed by real-time quantitative PCR before and after intervention. Concentrations of fecal short chain fatty acids were determined using gas chromatography.
  
  
  RESULTS
  Ratios of Bacteroides-Prevotella-Porphyromonas group to Firmicutes belonging bacteria, including Clostridium cluster XIV, Blautia coccoides_Eubacteria rectale group and Roseburia intestinalis, were significantly increased (p ≤ 0.05) after administration of Ls-33. The cell numbers of fecal bacteria, including the groups above as well as Clostridium cluster I, Clostridium cluster IV, Faecalibacterium prausnitzii, Enterobacteriaceae, Enterococcus, the Lactobacillus group and Bifidobacterium were not significantly altered by intervention. Similarly, short chain fatty acids remained unaffected.
  
  
  CONCLUSIONS
  L. salivarius Ls-33 might modify the fecal microbiota in obese adolescents in a way not related to metabolic syndrome.
  
  
  BACKGROUND
  NCT 01020617.
authors.affiliation: University of Copenhagen, Faculty of Science, Department of Food Science, Rolighedsvej 30, Frederiksberg 1958, Denmark. Electronic address: nf@life.ku.dk.
authors.forename: Nadja
authors.initials: N
authors.lastname: Larsen
authors.forename: Finn K
authors.initials: FK
authors.lastname: Vogensen
authors.forename: Rikke Juul
authors.initials: RJ
authors.lastname: Gøbel
authors.forename: Kim F
authors.initials: KF
authors.lastname: Michaelsen
authors.forename: Sofia D
authors.initials: SD
authors.lastname: Forssten
authors.forename: Sampo J
authors.initials: SJ
authors.lastname: Lahtinen
authors.forename: Mogens
authors.initials: M
authors.lastname: Jakobsen
mesh_terms: D000293:Adolescent; D002648:Child; D004269:DNA, Bacterial / Q000302:isolation & purification; D004311:Double-Blind Method; D005232:Fatty Acids, Volatile / Q000032:analysis; D005243:Feces / Q000382:microbiology*; D006094:Gram-Positive Bacteria; D006801:Humans; D007778:Lactobacillus; D024821:Metabolic Syndrome / Q000628:therapy; D064307:Microbiota; D009765:Obesity / Q000628:therapy; D019936:Probiotics / Q000008:administration & dosage*
chemical_list: D004269:DNA, Bacterial; D005232:Fatty Acids, Volatile
keywords: Fecal microbiota; Lactobacillus salivarius; Obesity; Probiotics