ORIGINAL RESEARCH article
Front. Nutr.
Sec. Nutritional Epidemiology
Volume 12 - 2025 | doi: 10.3389/fnut.2025.1602787
Association between the Newly Proposed Dietary Index for Gut Microbiota and Thyroid Function: NHANES 2007-2012
Provisionally accepted
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
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Aims: 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.Methods: 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. Results: After controlling for all covariates, higher DI-GM scores were significantly associated with lower levels of free triiodothyronine (FT3) (β = -0.043, 95% CI = -0.077,-0.010, P for trend = 0.010), free thyroxine (FT4) (β = -0.011, 95% CI = -0.021,-0.002, P for trend = 0.027), and total thyroxine (TT4) (β = -0.127, 95% CI = -0.237,-0.017, P 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 leveals (β = -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 (β = -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).Conclusion: 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.
Keywords: Dietary Index for Gut Microbiota, Thyroid function, Gut Microbiota, National Health and Nutrition Examination Survey, Cross-sectional study
Received: 31 Mar 2025; Accepted: 04 Jun 2025.
Copyright: © 2025 Peng, guo, zhang and Xiao. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
zhiqiang zhang, Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
Weidong Xiao, Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
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