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

• Register: ISRCTN
• Last refreshed on: 30 April 2018
• Main ID: ISRCTN96117208
• Date of registration: 20/03/2018
• Prospective Registration: No
• Primary sponsor: Universidad Santo Tomás
• Public title: Effects of yogurt containing probiotics on salivary Streptococcus mutans and Lactobacillus sp. counts in children
• 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
• Date of first enrolment: 16/07/2017
• Target sample size: 60
• Recruitment status: Completed
• URL: http://isrctn.com/ISRCTN96117208
• Study type: Interventional
• Study design: Single-centre single-blind randomised placebo-controlled trial (Prevention)

Countries of recruitment

Colombia

Contacts

• Name: Jose Pieruccini

• Name: Martha Rodríguez

Key inclusion & exclusion criteria

Inclusion criteria: 1. Healthy children
2. Both genders
3. Age 6-12 years old
4. Lactose tolerant
Exclusion criteria: 1. Dry mouth or xerostomy
2. Morbid obesity
3. Antibiotic therapy

Age minimum:
Age maximum:
Gender: Both

Health Condition(s) or Problem(s) studied

Healthy children not being under antibiotic therapy the two previous months to the start of the intervention
Not Applicable

Intervention(s)

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.

Primary Outcome(s)

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(s)

Salivary pH measured using a calibrated digital pH-meter and buffering capacity at baseline and at the end of the intervention period

Secondary ID(s)

GIFODONTP42014

Source(s) of Monetary Support

Universidad Santo Tomás

Ethics review

Status:
Approval date:
Contact:

The Research Ethics Committee of the Dentistry School at the Universidad Santo Tomas in Bucaramanga (Colombia), 22/05/2014

Results

• Results available: Yes
• Date Completed: 24/11/2017