Uncovering a Causal Connection between Gut Microbiota and Six Thyroid Diseases: A Two-Sample Mendelian Randomization Study.

BACKGROUND

Recent studies have established associations between the gut microbiota (GM) and thyroid diseases (TDs). However, their causal relationships remain elusive.

METHODS

To investigate this causality, we conducted a two-sample Mendelian randomization (MR) analysis using genome-wide association study (GWAS) data from MiBioGen and FinnGen, with GM as the exposure and six TDs as outcomes.

RESULTS

We identified 32 microbial taxa linked to the risk of six TDs. The , , and exhibited protective effects against nontoxic diffuse goiter (NDG). Conversely, an increased risk of NDG was associated with , , , , and . and were protective against nontoxic multinodular goiter (NMG), while the and heightened NMG risk. Protective effects against nontoxic single thyroid nodule (NSTN) were observed with , , and , whereas increased risk was linked to , the , and . , , and offered protection against thyrotoxicosis with Graves' Disease (GD), while the , , , , , and were risk factors. For thyrotoxicosis with Plummer Disease (PD), protective taxa included and , whereas , , , , , and increased risk. Lastly, was protective against thyrotoxicosis with toxic single thyroid nodule (TSTN), while increased risk was associated with , , and .

CONCLUSIONS

Our findings support a causal relationship between specific GM and TDs at the genetic level, laying the foundation for future research into potential mechanisms and the identification of novel therapeutic targets.