Skip to main content
OpenTrials
Completed

NCT Number: NCT03748017

The Probiotic for Oral Health (PRO Health) Study

The PRO Health Study is a single-center, prospective, double-blind, randomized, placebo-controlled trial of streptococcus-containing supplementation in healthy adults.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Age range

21 year–45 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of California, Davis

Davis, California, 95616, United States

About this study

Upon enrollment, healthy adults will enter a 1-week lead-in period which serves as an opportunity to collect baseline saliva samples and complete daily logs. Subjects that meet eligibility criteria on Day 7 will be randomized into 1 of 2 groups, receiving either a placebo-control or a streptococcus-containing probiotic supplement. Supplementation will begin on Day 8 and will continue for a total of 14 consecutive days. Participants will be observed for an additional 2 weeks following cessation of supplementation. The total duration of the study will be approximately 5 weeks. Saliva samples will be collected on 7 occasions and participants will be asked to complete questionnaires and daily diet and health logs throughout the course of the study.

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

  • Healthy adults;
  • Age 21-45 years of age;
  • BMI between 18-30;
  • No history of infectious disease; heart, metabolic, autoimmune endocrine, liver, or kidney diseases; GI related conditions such as malabsorption disease, Crohn's disease, colitis, inflammatory bowel disease; Type 1 or 2 diabetes mellitus, any type of cancer, heart disease;
  • Practices good oral hygiene according to the American Dental Association with brushing teeth between 1-2 times per day;
  • Willingness to only use the study toothpaste to brush or clean teeth and refrain from using any other oral-care products such as other toothpaste, mouthwash, rinses and breath-sprays during the five-week study period;
  • Willingness to limit consumption of raw onions or garlic and fermented foods such as sauerkraut, pickles, miso, and kimchi during the five-week study period;
  • Non-alcohol consumers or those who consume alcohol in moderation defined as having up to 1 drink per day for women and up to 2 drinks per day for men;
  • Willingness to avoid binge drinking during the study period defined by the Centers for Disease Control and Prevention as: This pattern of drinking usually corresponds to 5 or more drinks on a single occasion for men or 4 or more drinks on a single occasion for women, generally within about 2 hours;
  • Willingness to refrain from drinking any alcohol within 24 hours of each saliva sample collection;
  • Willingness to refrain from using illicit drugs during the five-week study;
  • Willingness to refrain from using tobacco (smoking or chewing) or smoking marijuana during the five-week study period;
  • Willingness to refrain from intake of probiotics, kombucha, or yogurt during the five-week study period;
  • Willingness to refrain from consuming more than 1 package of sugary candy and from chewing more than 1 package of chewing gum during the five-week study period;
  • Willingness to refrain from having any non-emergency, elective oral surgeries, dental procedures or dental teeth cleanings during the five-week study period.

Exclusion criteria

  • Currently pregnant or plans to become pregnant several weeks prior to enrollment and during the five-week study period;
  • History of periodontal disease, or gingivitis;
  • Dental trauma or injury to the teeth and/or periodontium (gums, periodontal ligament, alveolar bone), and nearby soft tissues such as the lips, tongue within the past 4 weeks;
  • Any oral surgery or intensive procedures made to the oral cavity (such as fillings, wisdom tooth extraction, root canal, dental implants, etc.) within the past 4 weeks;
  • Routine dental cleaning within the past 4 weeks;
  • Use of probiotics, kombucha, or yogurt/kefir within the past 7 days of enrollment;
  • Use of probiotics containing S. salivarius within the past 8 weeks of enrollment;
  • Use of oral or IV antibiotics within the past 8 weeks of enrollment;
  • Consumption of more than one package of sugary candy (hard candy, gummy candy, mints, etc.) per day;
  • Use of more than one package of chewing gum (sugary or sugarless) per day;
  • Use of mouthwashes, mouth-rinses or breath-sprays more than three times per day;
  • Current tobacco (smoking or chewing) or E-cigarette users or individuals who quit using less than one year before enrolling in the study;
  • Frequent marijuana smoking or vaping, or use of other illicit drugs (must be no more than 12 times within the past year and no more than once per month);
  • Marijuana smoking or vaping or use of other illicit drugs within the past 4 weeks;
  • Excessive alcohol drinkers: For men, heavy drinking is typically defined as consuming 15 drinks or more per week. For women, heavy drinking is typically defined as consuming 8 drinks or more per week;
  • Individuals who live within the same household or who are in intimate relationships with current or past study participants (to avoid horizontal transfer of the oral microbiome);
  • Anyone the investigator feels isn't an applicable participant.

Treatment and study plan

Placebo-Control Supplement

Dietary Supplement

A once-daily oral dose of the placebo-control supplement will be consumed by adults for 14 consecutive days.

Streptococcus-Containing Probiotic Supplement

Dietary Supplement

A once-daily oral dose of the streptococcus-containing probiotic supplement will be consumed by adults for 14 consecutive days.

Primary outcomes

  1. Oral Streptococci levels in adults at 22 days - difference between S. Salivarius and placebo

    Time frame: 22 Days

    The difference in levels of oral Streptococci between a streptococcus-containing probiotic supplement (e.g., S. salivarius K12) and placebo-control supplement on Day 22.

Secondary outcomes

  1. Oral Streptococcus levels

    Time frame: Change from baseline, days 10, 14, 22, 28, 36

    The difference in levels of Streptococci upon intake of a streptococcus-containing probiotic supplement (e.g., S. salivarius K12) before, during and after the intervention compared with a placebo-control supplement.

  2. Oral microbiome

    Time frame: Change from baseline, days 10, 14, 22, 28, 36

    The difference in the salivary microbiome before, during and after intake of a streptococcus-containing probiotic supplement (e.g., S. salivarius K12) and placebo-control supplement.

  3. Number of stools per day

    Time frame: Change from baseline, days 10, 14, 22, 28, 36

    The relationship between supplementation and number of stools per day.

  4. Changes in stool consistency

    Time frame: Change from baseline, days 10, 14, 22, 28, 36

    The relationship between supplementation and number of stools per day, rated using the Bristol Stool Scale.

  5. Changes in stool firmness

    Time frame: Change from baseline, days 10, 14, 22, 28, 36

    The relationship between supplementation and number of stools per day, rated using a continuous scale of 1 to 10 (1 = extremely watery, almost entirely liquid to 10 = extremely hard, difficult to pass).

Sponsors and collaborators

Lead sponsor

University of California, Davis

Other

Collaborators

  • Renew Life Formulas Inc

Registry information

Acronym: PRO Health

Important dates

Study start
2018
Primary completion
2019
Study completion
2021
First posted
Nov 20, 2018
Registry last updated
Nov 28, 2023

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.

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