Causal relationship between gut microbiota and dental caries: a two-sample mendelian randomization study

In recent years, an increasing number of studies have revealed a close relationship between the gut microbiota and a variety of human diseases. At the same time, it has also been shown that dysregulation of the oral microbiota may lead to changes in the gut microbiota. However, it remains unclear whether the gut microbiota affects the occurrence and development of oral diseases. Therefore, the aim of this study was to explore the potential effects of gut microbiota on dental caries and to reveal possible mechanisms of the gut-oral microbiota axis.

First, gut microbiota and dental caries data from genome-wide association studies (GWAS) were analyzed using Mendelian randomization analysis. Inverse variance weighted (IVW) was used as the main criterion (P value < 0.05). Then, MR-Egger regression, IVW regression and leave-one-out tests were used to test the reliability and stability of the mendelian randomization results. Finally, the potential mechanisms and significance of the relationship between gut microbiota and dental caries were explored.

The analysis showed that Eubacteriumbrachygroup [odds ratio (OR) = 1.001, 95% confidence interval (CI): 1.000-1.002, P = 0.046] and Terrisporobacter (OR = 1.002, 95% CI: 1.0001-1.0041, P = 0.035) were positively correlated with dental caries. Escherichia.Shigella (OR = 0.997, 95% CI: 0.995-0.999, P = 0.047), Oscillibacter (OR = 0.998, 95% CI: 0.997-0.999, P = 0.038), RuminococcaceaeUCG014 (OR = 0.998, 95% CI: 0.996-0.999, P = 0.044) and Oscillospira (OR = 0.997, 95% CI: 0.995-0.999, P = 0.038) were negatively correlated with dental caries.

The present study demonstrated a significant causal relationship between the gut microbiota and the development of dental caries, providing new insights into influencing the development of dental caries by affecting the composition of the gut microbiota.