Probiotic Modulation of Oral Microbiota
Condition: Microbial Colonization
MeSH terms: Communicable Diseases; Infections
Study type: Interventional

Summary: 
      Targeting human microbiota, in particular those of the gastrointestinal tract, by means of
      prebiotics, probiotics, symbiotics or antibiotics has gained interest for its potential in
      the management of human health. Oral bacterial communities have been extensively studied over
      the last decade both in normal and pathological states; however, little data are available on
      the possibility to modify microbiota composition in a controlled and 'non-aggressive' manner
      by using probiotics, in order to improve oral health.

      Saliva contains microorganisms attached to exfoliated human cells and released from oral
      biofilms; its microbiota is most similar (proportionally) to those of the dorsal and lateral
      tongue. In addition, bacteria belonging to genera Porphyromonas, Tannerella and Treponema,
      which contain species associated with periodontitis, are consistently identified in saliva.
      Salivary microbial communities are relatively stable and thus potentially interesting as an
      indicator of oral and general health. Indeed, it has been suggested that interventions aimed
      at improving oral health should target mucosal microbiota (to which saliva is most similar)
      in addition to dental microbial communities. Whole saliva also constitutes an alternative to
      gingival crevicular fluid when analysing analytes present in periodontal pockets. It has been
      suggested that saliva reflects a consensus inflammatory status of the whole mouth with
      potentially significant clinical relevance.

      Strain K12 of Streptococcus salivarius is available internationally as a food supplement,
      notably for oral hygiene. Several studies investigated the effectiveness of S. salivarius as
      a probiotic in the context of pharyngeal infections, halitosis, plaque formation and caries.
      Our study will focus on the effects of supplementation with this commercially available oral
      probiotic on the resident microbiota and inflammatory markers in order to identify signatures
      associated with resistance/susceptibility to colonization by probiotic strains.
    

Detailed description: 
      OBJECTIVES

      This is a monocentric, prospective, cross-over, randomized, double-blinded study in which all
      participants will receive placebo and active probiotic treatment, 15 of which will first be
      treated with placebo and then will be given probiotics. The other 15 participants will first
      get probiotics and then, after a 3-week wash out period, the placebo.

      The main objective of the study is to assess changes in salivary microbiota profiles and
      inflammatory markers following S. salivarius probiotic treatment. Our secondary objective is
      to identify correlations between specific salivary microbial taxa (subspecies to phylum
      levels) and inflammatory markers. Clinical outcome is not the focus of this study, although
      basic information about the oral health will be measured.

      METHODOLOGY

      BIOTICS-O (Burgerstein) probiotic that will be used is a commercial food supplement available
      over the counter in the pharmacy as blister packs of 30 lozenges containing 10^9 CFU of S.
      salivarius K12. Participants will let melt the lozenge after tooth brushing in the evening.

      Placebo lozenges (inactivated probiotic) will have the same look, taste and smell as the
      active treatment lozenges, and they will be administered in the same way as the active
      treatment lozenges.

      Metagenomic analysis of the microbiota:

      Indexed paired-end metagenomic libraries will be prepared using DNA extracted from saliva and
      sequenced for 2x150 cycles on an Illumina NovaSeq 6000 instrument to generate 5-10 million
      read pairs per sample. Our standard metagenomic analysis pipeline (HUGE-MAP) will be used; it
      includes: (i) read quality filtering; (ii) removal of replicate sequences; (iii) removal of
      read pairs that match human genome sequence and, (iv) classification of read pairs with CLARK
      against the collection of NCBI reference and representative bacterial, archaeal and fungal
      genomes, as well as Latest RefSeq NCBI genomes of prophages and DNA virus families whose
      members may infect humans. Functional assignments i.e. profiling the presence/absence and
      abundance of microbial gene families and pathways will be performed using MG-RAST server.
      Bacterial abundance will be measured by qPCR and/or relative to the number of reads obtained
      from the spiked calibrator.

      Cytokine measurements:

      Salivary cytokines (IL-1β, IL-6, IL-8, TNF-alpha) analysis will be performed using a
      Salimetrcs Core Cytokine Panel - 4-plex.

      OBJECTIVES

      This is a monocentric, prospective, cross-over, randomized, double-blinded study in which all
      participants will receive placebo and active probiotic treatment, 15 of which will first be
      treated with placebo and then will be given probiotics. The other 15 participants will first
      get probiotics and then, after a 3-week wash out period, the placebo.

      The main objective of the study is to assess changes in salivary microbiota profiles and
      inflammatory markers following S. salivarius probiotic treatment. Our secondary objective is
      to identify correlations between specific salivary microbial taxa (subspecies to phylum
      levels) and inflammatory markers. Clinical outcome is not the focus of this study, although
      basic information about the oral health will be measured.

      METHODOLOGY

      BIOTICS-O (Burgerstein) probiotic that will be used is a commercial food supplement available
      over the counter in the pharmacy as blister packs of 30 lozenges containing 10^9 CFU of S.
      salivarius K12. Participants will let melt the lozenge after tooth brushing in the evening.

      Placebo lozenges (inactivated probiotic) will have the same look, taste and smell as the
      active treatment lozenges, and they will be administered in the same way as the active
      treatment lozenges.

      Metagenomic analysis of the microbiota:

      Indexed paired-end metagenomic libraries will be prepared using DNA extracted from saliva and
      sequenced for 2x150 cycles on an Illumina NovaSeq 6000 instrument to generate 5-10 million
      read pairs per sample. Our standard metagenomic analysis pipeline (HUGE-MAP) will be used; it
      includes: (i) read quality filtering; (ii) removal of replicate sequences; (iii) removal of
      read pairs that match human genome sequence and, (iv) classification of read pairs with CLARK
      against the collection of NCBI reference and representative bacterial, archaeal and fungal
      genomes, as well as Latest RefSeq NCBI genomes of prophages and DNA virus families whose
      members may infect humans. Functional assignments i.e. profiling the presence/absence and
      abundance of microbial gene families and pathways will be performed using MG-RAST server.
      Bacterial abundance will be measured by qPCR and/or relative to the number of reads obtained
      from the spiked calibrator.

      Cytokine measurements:

      Salivary cytokines (IL-1β, IL-6, IL-8, TNF-alpha) analysis will be performed using a
      Salimetrix Core Cytokine Panel - 4-plex..

      Samplings will be performed at weeks 1, 4, 7, 10, 13, 16 and 19.
    

Intervention name(s): Probiotics-O (Burgerstein); Placebo [inactivated Probiotics-O (Burgerstein)]
Intervention type(s): Dietary Supplement; Other
Intervention description(s): Topical oral treatment with the probiotic Streptococcus salivarius K12 (BIOTICS-O, Burgerstein) in form of a lozenge, daily, during 3 weeks.; Topical oral treatment with the placebo [inactivated probiotic Streptococcus salivarius K12 (BIOTICS-O, Burgerstein)] in form of a lozenge, daily, during 3 weeks.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Other