Effects of yogurt containing probiotics on salivary Streptococcus mutans and Lactobacillus sp. counts in children

ISRCTN	ISRCTN96117208
DOI	https://doi.org/10.1186/ISRCTN96117208
Secondary identifying numbers	GIFODONTP42014

Submission date: 30/12/2017
Registration date: 20/03/2018
Last edited: 13/02/2018

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Other

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Background and study aims
Probiotics are live bacteria and yeasts promoted as having various health benefits. Fermented foods contain several probiotic bacteria that provide benefits especially on a digestive level. Previous research has analyzed the effect of probiotics in the mouth and have shown that certain probiotic microorganisms could reduce the saliva levels of the bacteria Mutans streptococci and Lactobacilli sp., which play an important role in the development of tooth cavities, but this effect has not been widely assessed for two probiotics (Lactobacillus casei and Lactobacillus acidophilus) available in some commercial yogurt brands in Colombia (‘Original’ Yogurt, manufactured by Alpina S.A.). Therefore, the aim of this study is to assess the effects of Lactobacillus casei and Lactobacillus acidophilus available in yogurt on the saliva levels of Mutans streptococci and Lactobacilli sp. in a population of Colombian children aged 6-12.

Who can participate?
Healthy children aged 6-12

What does the study involve?
Participants are randomly allocated into two groups. Those in group A drink ‘Original’ yogurt containing probiotics (Lactobacillus casei and Lactobacillus acidophilus) and group B drink ‘Yogo-Yogo’ ordinary yogurt without probiotics. Every child receives 150 g of the assigned yogurt after their lunch for five week days during three months. The children are encouraged to maintain their normal oral hygiene habits and continue to brush their teeth daily.

What are the possible benefits and risks of participating?
The children who take part in this study are given the benefit of drinking a beverage with many nutrients which either had probiotics or did not. There are no risks because the yogurt used is available in all supermarkets in the city of Bucaramanga (Colombia).

Where is the study run from?
The charity restaurant “Maria Reina de las Misiones” (Colombia)

When is study starting and how long is it expected to run for?
November 2013 to November 2017

Who is funding the study?
Universidad Santo Tomas (Colombia)

Who is the main contact?
Prof. Martha J. Rodriguez
marthajuro@gmail.com

Contact information

Mr Jose Pieruccini
Public

Calle 147 No. 25 - 30 Palmas del Campo Torre C Apto. 402
Floridablanca
681004
Colombia

ORCID ID	0000-0002-5098-5130
Phone	+57 (0)3017850598
Email	josepieruccini@ustabuca.edu.co

Prof Martha Rodríguez
Scientific

Torres del Club, Carrera 21 # 36-83
Floridablanca
681004
Colombia

ORCID ID	0000-0001-7339-7836
Phone	+57 (0)315 8169925
Email	marthajuro@ustabuca.edu.co

Study information

Study design	Single-centre single-blind randomised placebo-controlled trial
Primary study design	Interventional
Secondary study design	Randomised controlled trial
Study setting(s)	Other
Study type	Prevention
Participant information sheet	Not available in web format, please use the contact details to request a patient information sheet
Scientific title	Effects of yogurt containing probiotics on salivary Streptococcus mutans and Lactobacillus sp. counts in Colombian children aged from 6 to 12 years: a randomised controlled clinical trial
Study objectives	Lactobacillus casei and Lactobacillus acidophilus probiotics which are available in a yogurt called ‘Original’ distributed by Alpina S.A. reduce salivary Streptococcus mutans and Lactobacillus sp. counts in six to twelve year old Colombian children.
Ethics approval(s)	The Research Ethics Committee of the Dentistry School at the Universidad Santo Tomas in Bucaramanga (Colombia), 22/05/2014
Health condition(s) or problem(s) studied	Healthy children not being under antibiotic therapy the two previous months to the start of the intervention
Intervention	The children were randomised by block randomisation into group A (intervention arm: ‘Original’ probiotics yogurt containing Lactobacillus casei and Lactobacillus acidophilus) or group B (placebo control arm: ‘Yogo-Yogo’ ordinary yogurt without probiotics). Every participant received 150g of the assigned intake after their lunch during weekdays only, for a three month period. Microbiological examinations were performed at baseline and at the end of the intervention period. Samples of stimulated whole saliva were collected directly into sterile sample bottles. In the laboratory, samples were vortexed for 30 seconds and serially diluted from 10-1 to 10-3. Two inoculums for each dilution were plated on selective agar, Mitis Salivarius-Bacitracin agar for Streptococcus mutans and Rogosa agar for Lactobacillus sp. The agar plates were coded and anaerobically incubated at 37°. The number of CFU were identified based on their morphology, size, and color with the help of a digital colony counter 24 hours after incubation for Rogosa agar plates and 48 hours for Mitis Salivarius-Bacitracin agar plates. Biochemical identification tests were also used for identification of microorganisms. CFU of individual species were estimated by a single trained investigator.
Intervention type	Supplement
Primary outcome measure	Streptococcus mutans and Lactobacillus sp. Colony Forming Units (CFU) counts; microbiological examinations performed at baseline and at the end of the intervention period
Secondary outcome measures	Salivary pH measured using a calibrated digital pH-meter and buffering capacity at baseline and at the end of the intervention period
Overall study start date	01/11/2013
Completion date	24/11/2017

Eligibility

Participant type(s)	Healthy volunteer
Age group	Child
Lower age limit	6 Years
Upper age limit	12 Years
Sex	Both
Target number of participants	60
Key inclusion criteria	1. Healthy children 2. Both genders 3. Age 6-12 years old 4. Lactose tolerant
Key exclusion criteria	1. Dry mouth or xerostomy 2. Morbid obesity 3. Antibiotic therapy
Date of first enrolment	16/07/2017
Date of final enrolment	16/08/2017

Locations

Countries of recruitment

Colombia

Study participating centre

Comedor Infantil Maria Reina de las Misiones (a charity restaurant for children)

Bucaramanga
681002
Colombia

Sponsor information

Universidad Santo Tomás
University/education

Carrera 27 No. 180 - 395
Autopista Floridablanca
Floridablanca
681004
Colombia

Phone	6800801
Email	decodo@ustabuca.edu.co
Website	http://www.ustabuca.edu.co/
"ROR"	https://ror.org/01x628269

Funders

Funder type

University/education

Universidad Santo Tomás

No information available

Results and Publications

Intention to publish date	02/02/2018
Individual participant data (IPD) Intention to share	Yes
IPD sharing plan summary	Available on request
Publication and dissemination plan	Planned publication in a high-impact peer reviewed journal.
IPD sharing plan	The datasets generated during and/or analysed during the current study are/will be available upon request from Prof. Martha J. Rodriguez (marthajuro@gmail.com or marthajuro@ustabuca.edu.co).