Study will follow a randomized, double-blind, placebo-controlled design with two groups in parallel,N of 40 patients in 6 weeks of follow up for the evaluation of two different posology models (daily consumption of probiotic gum, with or without previous professional oral cleaning). Probiotics have recently been used to combat oral diseases (plaque control, caries, halitosis, etc.), as a non-invasive natural therapy.

The study will follow a randomized, double-blind, placebo-controlled design with two groups in parallel, for the evaluation of two different posology models (daily consumption of probiotic gum, with or without previous professional oral cleaning). Probiotics have recently been used to combat oral diseases (plaque control, caries, halitosis, etc.), as a non-invasive natural therapy.

The aim of this study is to assess whether the daily consumption of AB-DENTALAC gum allows the colonization of strains L.plantarum KABP051 (CECT7481) and L.brevis KABP052 (CECT7480) in the oral microbiota, and to confirm the absence of side effects, with the following setup:

1. Number of patients to be randomized:40
2. Number of visits per patient: 2

The study will determine the index of plaque and gingival index as a measure of oral health. The presence of Lactobacillus in the samples collected by qPCR will also be quantified.

The patient will benefit from a buccal revision and control by a periodontist for 6 weeks. It will also help subsequent patients to obtain a better treatment (if the results are significant). No harm is expected to participate, it is a minimal risk study, with non-invasive exploratory tests and a product suitable for human consumption and marketed in Europe since 2012.

The potential patients to participate in the study will be healthy patients, so if they do not wish to participate they will not need alternative treatment. The objective of the study is to see if the probiotic is able to colonize the mouth in healthy patients, it is not a study to demonstrate the effectiveness of the product.

If there is any serious adverse effect (something totally unexpected being a product with probiotic strains QPS), the patient will be advised to stop taking the product immediately. It is not anticipated that the use of any additional treatment is necessary.

The promoter will provide all the necessary material for the study: 60 cases of placebo chewing gum, 60 cases of probiotic chewing gum, and cleaning material (toothbrush and fluoridated toothpaste) for all patients.

Statistical analysis of bacterial colonization will be performed using Student's T with logarithmic transformation of data if required, considering a two-tailed P <0.05 as significance cut-off.

Inclusion Criteria:

• Women and men between 18-55 years.
• Capacity to understand the procedures and implications of the study.
• Gingival Index <1,5 (Löe and Silness, Acta Odontol Scand. 1963. 21:533-51)
• Plaque Index <2,0 (Löe and Silness, Acta Odontol Scand. 1963. 21:533-51)
• Periodontal pocket depth <5 mm

Exclusion Criteria:

• Less than 20 natural teeth
• More than 2 untreated caries at the time of enrollment
• Current orthodontic or periodontal treatment
• Hypersensitivity or allergy to any of the ingredients of the experimental product
• Consumption of antibiotics in the 8 weeks prior to treatment
• Use of probiotics designed to improve oral health, or having consumed them during the 8 weeks prior to the study
• Consumption of any type of probiotic during the 4 weeks prior to the study
• Usual consumption of clorhexidine or other mouthwashes with bactericidal active ingredients during the 30 days before the start of the study
• Pregnant or lactating women
• Participants with chronic diseases (eg, diabetes, kidney problems, cancer) or under chronic treatment

Once the patients have been selected according to the inclusion / exclusion criteria detailed below, they will be included in one of the treatment groups (control / study) in a random and random manner. The list of randomization and the labeling of the products will be carried out by independent personnel to the research team to ensure double blindness of the trial. The production of the probiotic products and control will be carried out in both cases in white boxes without any type of identification or difference between them.

The randomization will be made from an online software available at www.randomization.com. From the list of randomization generated by this software, the different products will be labeled with the patient number and the test code. The team of researchers will not have access to the randomization list. In this way, a correct randomization and double-blind trial is guaranteed.