Effect of low-dose radiation on thyroid function and the gut microbiota

Area of Science:

• Endocrinology
• Microbiology
• Radiation Biology

Background:

• The thyroid-gut axis is crucial for health, but the impact of low-dose ionizing radiation (LDR) on this axis remains unclear.
• Understanding LDR's effects on thyroid hormones and gut microbiota is essential for assessing health risks.

Purpose of the Study:

• To investigate the effects of LDR on thyroid hormone levels and gut microbiota composition in male C57BL/6J mice.
• To determine if observed changes are dose-dependent.

Main Methods:

• Mice were exposed to varying doses of X-ray radiation.
• Thyroid stimulating hormone (TSH) levels were measured using ELISA from peripheral blood.
• Gut microbiota composition was analyzed via 16S rRNA gene sequencing of stool samples.

Main Results:

• LDR exposure altered TSH levels, indicating a dose-dependent effect on thyroid function.
• While gut microbiota diversity and richness remained unchanged, specific bacterial abundances shifted.
• Significant changes included decreased Moraxellaceae and Enterobacteriaceae, increased Lachnospiraceae (dose-dependent), and altered levels of several uncultured bacteria, correlating with radiation dose.

Conclusions:

• LDR significantly impacts thyroid function and gut microbiota composition in mice.
• The observed alterations in bacterial abundances are directly correlated with the radiation dose received.
• These findings suggest potential implications for metabolic pathways and diagnostic efficacy.