The effect of ingestion of milk supplemented with salivaricin A-producing Streptococcus salivarius on the bacteriocin-like inhibitory activity of streptococcal populations on the tongue

FEMS Microbiol Ecol. 2007 Mar;59(3):584-91. doi: 10.1111/j.1574-6941.2006.00228.x. Epub 2006 Oct 27.


The colonization efficacies of salivaricin A (SalA)-producing Streptococcus salivarius strains 20P3 and 5 were compared when given in milk to 219 children, using either 2-day or 9-day dosing regimens. Colonization levels overall were superior for strain 5, and the 9-day dosing schedule resulted in higher levels of both initial colonization and strain persistence. The indigenous streptococcal tongue populations of 20 (10.9%) of the 189 children in the 2-day trial showed markedly increased SalA-like inhibitory activity following use of the S. salivarius-supplemented milk. All 20 of these children were found to have had relatively small (<5% of total S. salivarius) indigenous tongue populations of SalA-producing S. salivarius, and the relative proportions and/or inhibitory activity of these SalA producers on the childrens' tongues increased following ingestion of the S. salivarius-supplemented milk. Because SalA is known to be strongly inhibitory to Streptococcus pyogenes, an important implication of this study is that the consumption of SalA-producing probiotic S. salivarius could potentially help to effect a sustained increase in SalA-mediated protection against S. pyogenes infection.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Proteins / analysis
  • Bacterial Proteins / biosynthesis
  • Child
  • Child, Preschool
  • Colony Count, Microbial
  • Humans
  • Milk
  • Probiotics / administration & dosage*
  • Probiotics / metabolism
  • Species Specificity
  • Streptococcus / growth & development*
  • Streptococcus / isolation & purification
  • Streptococcus / metabolism*
  • Time Factors
  • Treatment Outcome


  • Bacterial Proteins
  • salivaricin A