: The effect of probiotics on salivary pH and flow rate in healthy subjects, A double blinded, randomized, controlled trial

Determining the effect of probiotics on salivary pH and flow rate in healthy subjects

The clinical trial has a control group, with parallel groups, double-blinded, randomized, phase 4 on 60 individuals. Random number table was used for randomization

Saliva samples are taken from the participants and their pH and weight are measured immediately after collection. Then group 1people are given 30 probiotic pills for one month. In group two, we use 30 placebo pills. At the end of one month, individuals in both groups are recalled and pH and saliva volume are measured. At the end of the intervention, a one-month follow-up is considered. For the principal investigator, participants, and analyst, the content of the tablets is blinded by randomly assigning codes one and two to the intervention and comparison groups in a separate center.

Inclusion criteria: Healthy people aged 20 to 40 who fill out an informed consent form؛ Exclusion criteria: Presence of a marked systemic disease؛ History of smoking and alcohol consumption؛ Pregnancy and lactation status؛ Patients with complete edentulousness؛ There are specific symptoms of dry mouth, including fissure lip and palate, rampant caries, fungal infections, adhesions of the tongue and mucous membranes to the teeth, etc؛ History of consumption of other products containing probiotic in the past month؛ History of taking any medication, including antibiotics, antiseptics, Saliva reducing or increasing drugs in the past month

In the intervention group, probiotic lozenges were used as a medicine. People take one of these pills a day for 30 days. In the comparison group, we use 30 placebo pills that have the same shape, color and composition as the previous pills but without probiotic content.

Number of digital scales؛ number of digital pH meter

In order to randomize, the layering method will be used, in which people are first, divided into four layers based on age and gender, and randomization will be done in each layer. Also, to create a balance in the samples allocated in each of the layers, the block randomization method will be used (The blocks will be formed using a table of random numbers and assigning code 1 to even numbers and code 2 to odd numbers and moving left to right in each layer).In this way, the extracted codes will be placed in sealed envelopes and when each participant enters the study, according to the mentioned layer, the envelopes of that layer will be randomly assigned to him. And according to the assigned codes in an independent center, the decision to allocate the main drug and placebo will be made (intervention and control).At all stages of the study, neither the participants nor the outcome assessment officials are aware of the groups and only follow the study based on the assigned codes and record the consequences.

Drugs and placebo in a separate center are marked with codes one and two assigned to the accident without informing the research team (participants, principal investigator and analyst).