Correlation between Bacterial Load of Streptococcus Mutans and Lactobacillus with Gluten-rich or gluten-free diet in patients with celiac disease

Introduction : Celiac disease is a multifactorial autoimmune gastrointestinal disorder. The aim of this study was to investigate the association between the frequency of salivary Streptococcus Mutans and Lactobacillus bacteria with gluten-containing and gluten-free diets in patients with celiac disease. Materials and Methods : The present study was a descriptive-analytical cross-sectional research conducted in 2025 on 75 participants, including 25 patients with celiac disease following a gluten-free diet, 25 patients with celiac disease consuming a gluten-containing diet, and 25 healthy individuals as the control group. Sampling was performed using a convenience method among patients with celiac disease. Demographic information and oral health indices were collected using a researcher-maed questionnaire. Saliva samples were collected using a non-stimulated method and analyzed to determine the colony counts of Streptococcus mutans and Lactobacillus acidophilus . Dental caries were assessed using the DMFT index. Data analysis was performed using SPSS software version 26. Descriptive and inferential statistical tests, Pearson correlation test, Spearman test, independent t-test, and chi-square test were applied for data analysis. Results : The mean age of participants in the control group, gluten-free diet group, and gluten-containing diet group was reported 29.8 ± 4.9 and 27.16 ± 5.13, and 29.24 ± 4.0 years, respectively. Comparison of Streptococcus mutans load among the study groups showed a statistically significant difference in colony counts between the three groups (p < 0.001). The number of Lactobacillus acidophilus colonies also demonstrated a statistically significant difference among the three groups (p < 0.001). The findings indicated that the mean DMFT index in patients with celiac disease consuming a gluten-containing diet was significantly higher than that of patients adhering to a gluten-free diet (p < 0.001). Conclusion : A gluten-containing diet in patients with celiac disease is associated with an increased load of cariogenic bacteria in saliva. These findings emphasize the importance of adherence to a gluten-free diet not only in reducing gastrointestinal symptoms but also in decreasing the risk of dental caries in patients with celiac disease.