Skip to main content
OpenTrials
Active, Not Recruiting

NCT Number: NCT07757360

Administration of Oral Probiotic Streptococcus Salivarius K12

The clinical trial is investigating the oral administration of probiotic Streptococcus salivarius K12 in the form of lozenges in healthy adults.

The main outcome measures are:

* Potential for Streptococcus salivarius K12 to colonise the oral cavity * Effect on other bacteria and Candida albicans in the oral cavity * Possible anti-inflammatory effect

Participants will:

* Take one lozenge containing Streptococcus salivarius K12 daily for 4 weeks * Attend 3 dental check-ups (before starting the probiotic treatment, and after 4 and 8 weeks) * Collect their own saliva samples in accordance with a sampling schedule

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Notify Me

Key information

Conditions

Oral Health

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Center for Dental Medicine

Zurich, Canton of Zurich, 8032, Switzerland

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Healthy volunteers
  • Adults (> 18 years)
  • no caries or periodontal disease

Exclusion criteria

Within the last 4 weeks before the trial, intake of...

  • anti-inflammatory drugs
  • antimicrobial substances
  • probiotics

Treatment and study plan

Probiotic

Dietary Supplement

The intervention consists of daily consumption of 1 lozenge BIOTICS-O for 4 weeks. BIOTICS-O are probiotic lozenges from the manufacturer Burgerstein Vitamine. They contain viable Streptococcus salivarius K12 (BLIS® K12, ATCC BAA-1024), 1 billion colony-forming units (CFU) per lozenge. BIOTICS-O is a dietary supplement available over the counter in Swiss pharmacies.

Other names: Streptococcus salivarius K12

Primary outcomes

  1. Impact of Streptococcus salivarius K12 on oral colonization

    Time frame: Baseline, intervention, and washout samples are collected according to a sampling schedule for 8 weeks.

    Quantitative PCR (qPCR) for Streptococcus salivarius and BLIS-containing plasmid counts in saliva samples

  2. Impact of Streptococcus salivarius K12 on oral colonization

    Time frame: Three dental plaque samples are analysed: baseline, intervention (after 4 weeks), and washout (after 8 weeks)

    Microbiome analysis of dental plaque samples (Bacteria, 16S rRNA gene sequencing)

  3. Impact of Streptococcus salivarius K12 on oral colonization

    Time frame: Three saliva samples are analysed: baseline, intervention (after 4 weeks), and washout (after 8 weeks)

    Determination of Candida albicans load by culture from saliva samples

Secondary outcomes

  1. Impact of Streptococcus salivarius K12 on salivary immune markers

    Time frame: Baseline, intervention, and washout samples (saliva) are collected according to a sampling schedule for 8 weeks.

    Determination of immune marker concentration (IL-1 beta, IL-6, IL-10, MMP-8, and TNF alpha) in saliva using the Luminex technology

Sponsors and collaborators

Lead sponsor

University of Zurich

Other

Registry information

Official study title

Administration of Oral Probiotic Streptococcus Salivarius K12: Oral Colonization, Impact on Oral Microbiome and Inflammatory Markers

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Aug 11, 2026
Registry last updated
Aug 11, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.