Probiotic bacteria affect the composition of salivary pellicle and streptococcal adhesion in vitro.
BACKGROUND
The use of probiotic bacteria is increasing worldwide and at least some of them can transiently colonize the oral cavity. Several studies have shown that probiotic bacteria, which are often thought of in relation only to intestinal health, can also affect the oral ecology, but the mechanisms for this are largely unknown. The aim of this study was to investigate in vitro if the probiotic bacteria used in commercial products affect the protein composition of the salivary pellicle and the adherence of other oral bacteria.


METHODS
Salivary pellicle on hydroxyapatite and the adhesion of two oral streptococci, Streptococcus mutans and Streptococcus gordonii, were used as a model.


RESULTS
Probiotic bacteria that bound to saliva-coated hydroxyapatite reduced the adhesion of S. mutans but the inhibitory effect on the adherence of S. gordonii was weaker. Salivary pellicle protein composition was modified by all the strains tested. The modifications in the pellicle affected the adherence of S. mutans but not of S. gordonii. Two of the proteins missing from the pellicles made of saliva-treated with the probiotic bacteria were identified as salivary agglutinin gp340 and salivary peroxidase. All bacterial strains bound salivary agglutinin gp340. The ability of the probiotic bacteria to degrade peroxidase was demonstrated with purified bovine lactoperoxidase and two of the probiotic strains.


CONCLUSIONS
This in vitro study showed that probiotic strains used in commercial products may affect the oral ecology by specifically preventing the adherence of other bacteria and by modifying the protein composition of the salivary pellicle.
Haukioja
A
A
Postgraduate School of Oral Health Sciences, Institute of Dentistry, Universeity of Turku, Turku, Finland. anna.haukioja@utu.fi
Loimaranta
V
V
Tenovuo
J
J
D000328:Adult; D000818:Animals; D001422:Bacterial Adhesion / Q000502:physiology*; D001644:Bifidobacterium / Q000502:physiology; D002021:Buffers; D002417:Cattle; D044622:Dental Pellicle / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry; D005260:Female; D006801:Humans; D007780:Lacticaseibacillus casei / Q000502:physiology; D052201:Lacticaseibacillus rhamnosus / Q000502:physiology; D013294:Lactococcus lactis / Q000502:physiology; D007784:Lactoperoxidase / Q000032:analysis; D010306:Parotid Gland / Q000378:metabolism; D009195:Peroxidase / Q000032:analysis; D019936:Probiotics / Q000494:pharmacology*; D011971:Receptors, Immunologic / Q000032:analysis; D012471:Salivary Proteins and Peptides / Q000032:analysis; D054773:Streptococcus gordonii / Q000502:physiology*; D013295:Streptococcus mutans / Q000502:physiology*; D013997:Time Factors
D002021:Buffers; D011971:Receptors, Immunologic; D012471:Salivary Proteins and Peptides; C116303:glycoprotein 340; D017886:Durapatite; D007784:Lactoperoxidase; D009195:Peroxidase