Safety Assessment of the Oral Cavity Probiotic Streptococcus salivarius K12

Streptococcus salivarius is a prominent member of the oral microbiota and has excellent potential for use as a probiotic targeting the oral cavity. In this report we document safety data relating to S. salivarius K12, including assessment of its antibiogram, metabolic profiles, and virulence determinants, and we examine the microbial composition of saliva following the dosing of subjects with K12.     

Human Systemic Immune Response to Ingestion of the Oral Probiotic Streptococcus salivarius BLIS K12

Probiotics and Antimicrobial Proteins - Streptococcus salivarius K12 is an oral probiotic known to contribute to protection against oral pathogenic bacteria in humans. Studies of immune responses...     

Safety assessment of the oral cavity probiotic Streptococcus salivarius K12

Streptococcus salivarius is a prominent member of the oral microbiota and has excellent potential for use as a probiotic targeting the oral cavity. In this report we document safety data relating to S. salivarius K12, including assessment of its antibiogram, metabolic profiles, and virulence determinants, and we examine the microbial composition of saliva following the dosing of subjects with K12.     

In vitro Inhibition of Clinical Isolates of Otitis Media Pathogens by the Probiotic Streptococcus salivarius BLIS K12

Otitis media is a common childhood infection, frequently requiring antibiotics. With high rates of antibiotic prescribing and increasing antibiotic resistance, new strategies in otitis media prevention and treatment are needed. The aim of this study was to assess the in vitro inhibitory activity Streptococcus salivarius BLIS K12 against otitis media pathogens. Efficacy of the bacteriocin activity of S. salivarius BLIS K12 against the otitis media isolates was assessed using the deferred antagonism test. Overall, 48% of pathogenic isolates exhibited some growth inhibition by S. salivarius BLIS K12. S. salivarius BLIS K12 can inhibit the in vitro growth of the most common pathogens.

     

Genome Sequence of the Lantibiotic Bacteriocin Producer Streptococcus salivarius Strain K12

Streptococcus salivarius is a prevalent commensal species of the oropharyngeal tract. S. salivarius strain K12 is an isolate from the saliva of a healthy child, used as an oral probiotic. Here, we report its genome sequence, i.e., the full sequence of the 190-kb megaplasmid pSsal-K12 and a high-quality draft 2.2-Gb chromosomal sequence.     

Anti-Inflammatory Properties of Streptococcus salivarius,a Commensal Bacterium of the Oral Cavity and Digestive Tract

Streptococcus salivarius is one of the first colonizers of the human oral cavity and gut after birth and therefore may contribute to the establishment of immune homeostasis and regulation of host inflammatory responses. The anti-inflammatory potential of S. salivarius was first evaluated in vitro on human intestinal epithelial cells and human peripheral blood mononuclear cells. We show that live S. salivarius strains inhibited in vitro the activation of the NF-κB pathway on intestinal epithelial cells. We also demonstrate that the live S. salivarius JIM8772 strain significantly inhibited inflammation in severe and moderate colitis mouse models. These in vitro and in vivo anti-inflammatory properties were not found with heat-killed S. salivarius, suggesting a protective response exclusively with metabolically active bacteria.     

Influence of Oral Probiotic <Emphasis Type="Italic">Streptococcus salivarius</Emphasis> K12 on Ear and Oral Cavity Health in Humans: Systematic Review

Traditionally, probiotics are linked to the good health of the intestine and most clinical studies focus on that field. Evidence of oral probiotic use for ear and oral cavity disease prevention with impact on human health is limited. This work reviews existing studies and literature on Streptococcus salivarius K12 as an oral probiotic and effects of S. salivarius K12 on human ear and oral cavity human health. The studies were accessed via database searches: MEDLINE, PubMed, and Elsevier. The search included/focused on/encompassed publications from 2003 to 2016 with keywords related to K12 Streptococcus salivarius, bacteriocin-like inhibitory substances (BLIS) K12, probiotic K12 salivarius, and K12 probiotic health effects. Only a small amount of studies was identified: the total of 68 studies was identified, 35 of which were relevant after screening, and 9 were included in the final analysis. Very little literature is available about the association/correlation between/connection/interrelation of S. salivarius K12 with/and human ear and oral cavity health. S. salivarius K12 may have a role in reducing the occurrence and/or severity of secretory otitis media (SOM) and also in prevention of streptococcal and viral pharyngotonsillitis in children. Research highlights that S. salivarius K12 has shown promising results in treatment of halitosis, but data are still deficient. Further studies need to be initiated to improve understanding of the association of oral probiotic S. salivarius K12 with human ear and oral cavity health.     

A preliminary study of the effect of probiotic Streptococcus salivarius K12 on oral malodour parameters

AIMS: To determine whether dosing with bacteriocin-producing Streptococcus salivarius following an antimicrobial mouthwash effects a change in oral malodour parameters and in the composition of the oral microbiota of subjects with halitosis. MATERIALS AND RESULTS: Twenty-three subjects with halitosis undertook a 3-day regimen of chlorhexidine (CHX) mouth rinsing, followed at intervals by the use of lozenges containing either S. salivarius K12 or placebo. Assessment of the subjects' volatile sulphur compound (VSC) levels 1 week after treatment initiation showed that 85% of the K12-treated group and 30% of the placebo group had substantial (>100 ppb) reductions. The bacterial composition of the saliva was monitored by culture and PCR-denaturing gradient gel electrophoresis (PCR-DGGE). Changes in the PCR-DGGE profiles occurred in most subjects following K12 treatment. In vitro testing showed that S. salivarius K12 suppressed the growth of black-pigmented bacteria in saliva samples and also in various reference strains of bacteria implicated in halitosis. CONCLUSIONS: Administration of bacteriocin-producing S. salivarius after an oral antimicrobial mouthwash reduces oral VSC levels. SIGNIFICANCE AND IMPACT OF THE STUDY: The outcome of this preliminary study indicates that the replacement of bacteria implicated in halitosis by colonization with competitive bacteria such as S. salivarius K12 may provide an effective strategy to reduce the severity of halitosis.     

Persistence of the Oral Probiotic Streptococcus salivarius M18 Is Dose Dependent and Megaplasmid Transfer Can Augment Their Bacteriocin Production and Adhesion Characteristics

Bacteriocin-producing probiotic Streptococcus salivarius M18 offers beneficial modulatory capabilities within the oral microbiome, apparently through potent inhibitory activity against potentially deleterious bacteria, such as Streptococcus pyogenes. The oral cavity persistence of S. salivarius M18 was investigated in 75 subjects receiving four different doses for 28 days. Sixty per cent of the subjects already had some inhibitor-producing S. salivarius in their saliva prior to probiotic intervention. Strain M18’s persistence was dependent upon the dose, but not the period of administration. Culture analysis indicated that in some individuals the introduced strain had almost entirely replaced the indigenous S. salivarius, though the total numbers of the species did not increase. Selected subjects showing either high or low probiotic persistence had their salivary populations profiled using Illumina sequencing of the V6 region of the 16S rRNA gene. Analysis indicated that while certain bacterial phenotypes were markedly modulated, the overall composition of the oral microbiome was not modified by the probiotic treatment. Megaplasmids encoding bacteriocins and adhesion factors were transferred in vitro to generate a transconjugant S. salivarius exhibiting enhanced antimicrobial production and binding capabilities to HEp-2 cells. Since no widespread perturbation of the existing indigenous microbiota was associated with oral instillation and given its antimicrobial activity against potentially pathogenic streptococci, it appears that application of probiotic strain M18 offers potential low impact alternative to classical antibiotic prophylaxis. For candidate probiotic strains having relatively poor antimicrobial or adhesive properties, unique derivatives displaying improved probiotic performance may be engineered in vitro by megaplasmid transfer.     

The Effect of Streptococcus salivarius K12 on Halitosis: a Double-Blind,Randomized, Placebo-Controlled Trial

This study was to evaluate the effect of Streptococcus salivarius K12 on tongue coating–associated halitosis. Twenty-eight subjects having tongue coating–associated halitosis were randomly divided into either a test or control group. For each of the 30 days, the test subjects sucked S. salivarius K12 tablet while the control subjects sucked placebo tablets. All the subjects did not take physical (tongue scraping) and chemical (antiseptic mouth-rinse) oral cavity pretreatment prior to use of the tablets. At baseline, and on the 1st, 7th, and 14th day after completing the course of tablets, the subjects were assessed for their organoleptic test (OLT) scores, volatile sulfur compound (VSC) levels, and tongue coating scores (TCS). During the course, all subjects kept their routine oral care habits without scraping their tongue coating. Plaque index, probing depth, and bleeding index were recorded at baseline and at the completion of the trial. On the 1st day following the end of tablet use, the OLT scores and VSC levels had significantly decreased in the test group when compared with the baseline values (P = 0.001 and P = 0.012). The TCS in the test group were also significantly decreased (P = 0.05). At days 7 and 14, the OLT scores in the test group were still significantly lower than the baseline levels (P = 0.006 and P = 0.039 respectively). However, there were no statistical differences with OLT, VSC, and TCS between the test group and the placebo group by analysis of multi-level regression model. The use of S. salivarius K12 did not have significant effect on halitosis with tongue coating cause when the tongue coating was not physically or chemically pre-treated, which implies removing tongue coating is required before Streptococcus salivarius K12 use.

     

Assessment of Efficacy of BLIS-Producing Probiotic K12 for the Prevention of Group A Streptococcus Pharyngitis: a Short Communication

Probiotics and Antimicrobial Proteins - The neutral outcome of the recently reported school-based trial of probiotic K12 (The effect of the oral probiotic Streptococcus salivarius K12 on group A...     

Fermentation of milk by Streptococcus salivarius subspecies salivarius and Streptococcus salivarius subspecies thermophilus and their use to the yoghurt manufacturer

Unlike Streptococcus salivarius subspecies thermophilus, Streptococcus salivarius subspecies salivarius fails to grow symbiotically in milk in the presence of Lacto-bacillus bulgaricus , does not produce large quantities of the flavour volatiles, acetal-dehyde or diacetyl and is unable to stimulate growth of Lact. bulgaricus by producing formate. Although Strep, salivarius subspecies salivarius and thermophilus have similar DNA base composition and belong in the same DNA homology group, the former is unsuitable for milk fermentations such as yoghurt because fermentation of milk using this organism results in products with poor flavour, aroma and texture.     

Effect of Streptococcus salivarius K12 on the in vitro growth of Candida albicans and its protective effect in an oral candidiasis model

Oral candidiasis is often accompanied by severe inflammation, resulting in a decline in the quality of life of immunosuppressed individuals and elderly people. To develop a new oral therapeutic option for candidiasis, a nonpathogenic commensal oral probiotic microorganism, Streptococcus salivarius K12, was evaluated for its ability to modulate Candida albicans growth in vitro, and its therapeutic activity in an experimental oral candidiasis model was tested. In vitro inhibition of mycelial growth of C. albicans was determined by plate assay and fluorescence microscopy. Addition of S. salivarius K12 to modified RPMI 1640 culture medium inhibited the adherence of C. albicans to the plastic petri dish in a dose-dependent manner. Preculture of S. salivarius K12 potentiated its inhibitory activity for adherence of C. albicans. Interestingly, S. salivarius K12 was not directly fungicidal but appeared to inhibit Candida adhesion to the substratum by preferentially binding to hyphae rather than yeast. To determine the potentially anti-infective attributes of S. salivarius K12 in oral candidiasis, the probiotic was administered to mice with orally induced candidiasis. Oral treatment with S. salivarius K12 significantly protected the mice from severe candidiasis. These findings suggest that S. salivarius K12 may inhibit the process of invasion of C. albicans into mucous surfaces or its adhesion to denture acrylic resins by mechanisms not associated with the antimicrobial activity of the bacteriocin. S. salivarius K12 may be useful as a probiotic as a protective tool for oral care, especially with regard to candidiasis.     

Pathways for lactose/galactose catabolism by Streptococcus salivarius

Using oligonucleotides derived from the N-terminal sequence of a triazine hydrolase from Nocardioides sp. strain C190, two DNA fragments containing trzN were cloned into Escherichia coli and their nucleotide sequences were determined. The 456-amino acid polypeptide predicted from the 1356-bp trzN ORF displayed significant similarity to triazine hydrolases from Pseudomonas and Rhodococcus isolates and belonged to the same amidohydrolase family. The trzN gene was flanked by two DNA sequences possessing 57 and 69% identity, respectively, at the protein level to Rhodococcus erythropolis sequences for a transposase and a transposase helper protein. Amplification primers specific to trzN were tested in soils inoculated with strain C190. The results demonstrated that the primers were specific to trzN, and could detect populations at 10(8) cfu g(-1) soil using 250-mg soil samples.     

Adaptation and Probiotic Potential of Lactobacilli,Isolated from the Oral Cavity and Intestines of Healthy People

The present study shows that, from 300 Lactobacillus strains isolated from the oral cavity and large intestine of 600 healthy people, only 9 had high antagonistic activity against pathogens and opportunistic pathogens. All antagonistic strains of lactobacilli have been identified by 16S rRNA sequencing and assigned to four species: Lactobacillus fermentum, Lactobacillus rhamnosus, Lactobacillus plantarum, and Lactobacillus casei. In addition, these lactobacilli appeared to be nonpathogenic and had some probiotic potential: the strains produced lactic acid and bacteriocins, showed high sensitivity to broad-spectrum antibiotics, and were capable of forming biofilms in vitro. With the help of PCR and specific primers, the presence of genes for prebacteriocins in L. plantarum (plnEF, plnJ, plnN) and L. rhamnosus (LGG_02380 and LGG_02400) has been revealed. It was found that intestinal strains of lactobacilli were resistant to hydrochloric acid and bile. Lactobacilli isolated from the oral cavity were characterized by a high degree of adhesion, whereas intestinal strains were characterized by average adhesion. Both types of lactobacilli had medium to high rates of auto-aggregation and hydrophobicity and could coaggregate with pathogens and opportunistic pathogens. Additionally, the ability of the lactobacilli strains to produce gasotransmitters, CH₄, CO₂, C₂H₆, CO, and NH₃, has been revealed.