Evaluation of Yoghurt with Probiotics Effect on Salivary IgA Concentration

Probiotics have been associated to various benefits on oral health, partially through regulation of local immunity. The purpose of this study was to evaluate the effect of probiotics on salivary IgA. This randomized, triple-blind trial was conducted on 40 healthy non-smoker volunteers. The subjects were assigned to two age- and sex-matched groups ingesting 200 g of a regular yoghurt (control) or a yoghurt containing probiotic bacteria (treatment group) once daily for 8 weeks. Unstimulated salivary samples were collected from the subjects at weeks 0, 4 and 8 of trial and total salivary IgA concentration was determined using ELISA. Saliva volume was measured and salivary IgA secretion rate was calculated. The differences in IgA means were statistically analyzed by repeated measurments (α=0.05). Over the trial period, no significant changes were found among the salivary IgA concentrations of control group; however, treatment group presented a non-significant increase (P>0.05). There were not significant differences in concentration and secretion rate between two groups at each time point of study (P>0.05). Within the limitations of this study, an 8-week period daily consumption of probiotic yoghurt could not alter the salivary IgA concentrations, although it persuades an increase trend in salivary IgA secretion rate.