title: Growth inhibition of oral mutans streptococci and candida by commercial probiotic lactobacilli--an in vitro study.
abstract: BACKGROUND
  Probiotic bacteria are suggested to play a role in the maintenance of oral health. Such health promoting bacteria are added to different commercial probiotic products. The aim of the study was to investigate the ability of a selection of lactobacilli strains, used in commercially available probiotic products, to inhibit growth of oral mutans streptococci and C. albicans in vitro.
  
  
  METHODS
  Eight probiotic lactobacilli strains were tested for growth inhibition on three reference strains and two clinical isolates of mutans streptococci as well as two reference strains and three clinical isolates of Candida albicans with an agar overlay method.
  
  
  RESULTS
  At concentrations ranging from 109 to 105 CFU/ml, all lactobacilli strains inhibited the growth of the mutans streptococci completely with the exception of L. acidophilus La5 that executed only a slight inhibition of some strains at concentrations corresponding to 107 and 105 CFU/ml. At the lowest cell concentration (103 CFU/ml), only L. plantarum 299v and L. plantarum 931 displayed a total growth inhibition while a slight inhibition was seen for all five mutans streptococci strains by L. rhamnosus LB21, L. paracasei F19, L. reuteri PTA 5289 and L. reuteri ATCC 55730. All the tested lactobacilli strains reduced candida growth but the effect was generally weaker than for mutans streptococci. The two L. plantarum strains and L. reuteri ATCC 55730 displayed the strongest inhibition on Candida albicans. No significant differences were observed between the reference strains and the clinical isolates.
  
  
  CONCLUSIONS
  The selected probiotic strains showed a significant but somewhat varying ability to inhibit growth of oral mutans streptococci and Candida albicans in vitro.
authors.affiliation: Paediatric Dentistry, Department of Odontology, Faculty of Medicine, Umeå University, S 901 85 Umeå, Sweden.
authors.forename: Pamela
authors.initials: P
authors.lastname: Hasslöf
authors.forename: Maria
authors.initials: M
authors.lastname: Hedberg
authors.forename: Svante
authors.initials: S
authors.lastname: Twetman
authors.forename: Christina
authors.initials: C
authors.lastname: Stecksén-Blicks
mesh_terms: D000898:Antibiosis / Q000502:physiology*; D002176:Candida albicans / Q000254:growth & development*; D006131:Growth Inhibitors / Q000494:pharmacology; D007778:Lactobacillus / Q000145:classification / Q000502:physiology*; D019936:Probiotics / Q000494:pharmacology*; D013045:Species Specificity; D013295:Streptococcus mutans / Q000254:growth & development*
chemical_list: D006131:Growth Inhibitors