Oral-Spray Bacillus Spore Probiotic in Preventing and Supporting Treatment of Dental Caries in Children

Summary

Despite advances in oral health care, cavities remain highly prevalent worldwide, especially among children. Conventional treatment methods focus on removing damaged tooth tissue but fail to completely eliminate or control pathogenic bacteria in the oral cavity, leading to a high risk of caries recurrence in the same or adjacent teeth. Probiotics are a promising biological therapy that can help restore balance in the oral microbiome.

Among probiotics, Bacillus species are unique because they form spores that make them stable under harsh conditions, such as heat and storage. They can also produce enzymes and natural compounds with antibacterial, anti-inflammatory, and protective effects. These features make Bacillus probiotics strong candidates for oral health applications.

This study is designed to evaluate the safety and efficacy of an oral-spray probiotic containing Bacillus subtilis ANA48 and Bacillus clausii ANA39 (LiveSpo® Smile CARE) in preventing and supporting the treatment of tooth decay in children. We hypothesize that this probiotic spray, when used regularly, will be safe and well-tolerated, while effectively reducing harmful bacteria in the mouth, preventing the progression of cavities, and improving overall oral health.

Study Design:

* Sample Size: 130 participants
* Study Location: a primary school in Hanoi, Vietnam Intervention Description: A total of 130 eligible participants will be randomly assigned to two groups (n = 65 per group).

Placebo Group will receive a 0.9% NaCl physiological saline, spray twice daily (morning and afternoon). Each application consists of two sprays at three sites (both dental arches and the front teeth), for a total of six sprays per use, continued for three consecutive months.

Smile Care Group will receive an oral-spray probiotics containing ≥ 1 billion CFU/mL × 20 mL of Bacillus subtilis and Bacillus clausii (LiveSpo Smile CARE). The dosage, frequency, and duration of use will be the same as in the placebo group.

All participants will receive the same standard dental care throughout the study, including the use of identical toothpaste, supervised weekly fluoride rinsing with 0.2% sodium fluoride (NaF), and scheduled follow-up visits. The probiotic and placebo sprays will be packaged in blinded bottles and administered according to the study protocol to maintain objectivity.

Study Duration: 12-18 months

Conditions

• Dental Caries

Interventions

DRUG

oral-spray 0.9% NaCl physiological saline solution

The oral-spray 0.9% NaCl physiological saline is prepared by extracting 20 mL from a 500 mL polypropylene bottle of 0.9% NaCl intravenous infusion (B. Braun, Germany; product declaration No. VD-32732-19). The solution is contained in an opaque plastic spray bottle identical to that used for the Smile Care.

COMBINATION_PRODUCT

Smile Care

LiveSpo® Smile CARE is manufactured as a Class-A medical device (product declaration No. 250002196/PCBA-HN) in compliance with manufacturing standards approved by the Hanoi Department of Health, Ministry of Health. The product is formulated as a 0.9% NaCl physiological saline solution plus Bacillus subtilis ANA48 and Bacillus clausii ANA39 at total concentration of ≥ 1 × 10⁹ CFU/mL (20 billion CFU/20 mL suspension).

Sponsors & Collaborators

• Hanoi Medical University

  collaborator OTHER

• Anabio R&D

  lead INDUSTRY

Principal Investigators

• Nga TT Pham, PhD. MD · Hanoi Medical University

• Thu TH Nguyen, Assoc. Prof. · Hanoi Medical University

• Anh TV Nguyen, Assoc. Prof. · Spobio Research Center, Anabio R&D

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

TRIPLE

Model

PARALLEL

Eligibility

Min Age

7 Years

Max Age

10 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2025-12-01

Primary Completion

2026-10-30

Completion

2027-05-01