Peng Ke, Guo Hanjie, Zhang Zhiqiang, Xiao Weidong
Department of General Surgery, Xinqiao Hospital, Army Medical University, Chongqing, China.
Front Nutr. 2025 Jun 26;12:1602787. doi: 10.3389/fnut.2025.1602787. eCollection 2025.
Diet-gut-thyroid axis has attracted increasing interest. The dietary index for gut microbiota (DI-GM) is a recently introduced measure of diet quality that represents gut microbiota diversity. However, its relationship with thyroid function has not been investigated. This study aimed to examine the unexplored relationship between DI-GM and thyroid function.
This cross-sectional study analyzed data from 6,126 participants aged ≥20 years in the National Health and Nutrition Examination Survey (NHANES). Linear regression models, smoothed curve fitting, and subgroup analyses were used to examine the relationship between DI-GM and thyroid function.
After controlling for all covariates, higher DI-GM scores were significantly associated with lower levels of free triiodothyronine (FT3) ( = -0.043, 95% CI = -0.077, -0.010, for trend = 0.010), free thyroxine (FT4) ( = -0.011, 95% CI = -0.021, -0.002, for trend = 0.027), and total thyroxine (TT4) ( = -0.127, 95% CI = -0.237, -0.017, for trend = 0.024). Smooth curve fitting analysis confirmed a linear relationship between DI-GM and FT3, FT4, and TT4 levels. Furthermore, subgroup analyses indicated that age may influence the negative correlation between DI-GM and FT4 levels, with participants aged < 40 years exhibiting a more pronounced decrease in FT4 levels ( = -0.090, 95% CI: -0.140, -0.041). Smoking status may modify the relationship between DI-GM and thyroid hormone levels, showing negative correlations for FT3 levels only in never smokers ( = -0.073, 95% CI = -0.114, -0.032) and for TT4 levels only in former smokers (β = -0.316, 95% CI = -0.511, -0.122). Notably, thyroglobulin antibodies levels exhibited opposing directional effects between never smokers (negative) and former/current smokers (positive).
Higher DI-GM scores were negatively correlated with lower FT3, FT4, and TT4 levels, with age and smoking status serving as key factors influencing this association.
饮食-肠道-甲状腺轴已引起越来越多的关注。肠道微生物群饮食指数（DI-GM）是最近引入的一种饮食质量衡量指标，代表肠道微生物群的多样性。然而，其与甲状腺功能的关系尚未得到研究。本研究旨在探讨DI-GM与甲状腺功能之间尚未被探索的关系。
这项横断面研究分析了美国国家健康与营养检查调查（NHANES）中6126名年龄≥20岁参与者的数据。使用线性回归模型、平滑曲线拟合和亚组分析来研究DI-GM与甲状腺功能之间的关系。
在控制所有协变量后，较高的DI-GM得分与较低水平的游离三碘甲状腺原氨酸（FT3）（β = -0.043，95%CI = -0.077，-0.010，趋势P值 = 0.010）、游离甲状腺素（FT4）（β = -0.011，95%CI = -0.021，-0.002，趋势P值 = 0.027）和总甲状腺素（TT4）（β = -0.127，95%CI = -0.237，-0.017，趋势P值 = 0.024）显著相关。平滑曲线拟合分析证实了DI-GM与FT3、FT4和TT4水平之间存在线性关系。此外，亚组分析表明年龄可能会影响DI-GM与FT4水平之间的负相关，年龄<40岁的参与者FT4水平下降更为明显（β = -0.090，95%CI：-0.140，-0.041）。吸烟状态可能会改变DI-GM与甲状腺激素水平之间的关系，仅在从不吸烟者中FT3水平存在负相关（β = -0.073，95%CI = -0.114，-0.032），仅在既往吸烟者中TT4水平存在负相关（β = -0.316，95%CI = -0.511，-0.122）。值得注意的是，甲状腺球蛋白抗体水平在从不吸烟者（负相关）和既往/当前吸烟者（正相关）之间表现出相反的方向效应。
较高的DI-GM得分与较低的FT3、FT4和TT4水平呈负相关，年龄和吸烟状态是影响这种关联的关键因素。
