Related Experiment Video
Updated: Sep 14, 2025
Generation of a Mouse Spontaneous Autoimmune Thyroiditis Model
Published on: March 17, 2023
Bifidobacterium depletion promotes goiter via gut-thyroid axis: evidence from Mendelian randomization and
Wenyong Liao1, Yang Jiang1, Jiwen Zhang1
1Beijing University of Chinese Medicine, Beijing, China.
Background:
While gut microbiota dysbiosis has been associated with thyroid disorders, its causal role in goiter pathogenesis remains unclear. We aimed to investigate whether specific gut microbial taxa causally influence goiter risk through the short-chain fatty acid (SCFA)-iodine-thyroid axis.
Methods:
We performed Mendelian randomization (MR) analysis using gut microbiota genome-wide association study (GWAS) data (MiBioGen consortium, n = 18,340) and goiter GWAS data (FinnGen R10, 10,312 cases/401,869 controls). Experimental validation included: (1) establishing a propylthiouracil (PTU)-induced goiter rat model with 16S rRNA sequencing of fecal samples, (2) targeted SCFAs quantification, (3) thyroid/serum iodine measurement, (4) thyroid hormone assays, and (5) sodium-iodide symporter (NIS) protein expression analysis.
Results:
MR analysis identified 10 gut microbial taxa causally associated with goiter risk (all p < 0.05), with Bifidobacterium bifidum showing protective effects (OR = 0.861, 95% CI: 0.764-0.971, p = 0.014). In goiter rats, 16S rRNA sequencing revealed eight differentially abundant microbial taxa including significantly reduced B. bifidum, accompanied by: (1) impairment of two butyrate synthesis pathways, (2) decreased levels of six SCFAs (including butyrate), (3) impaired thyroid iodine uptake, (4) downregulated NIS expression, and (5) thyroid dysfunction [reduced triiodothyronine (T3), thyroxine (T4), free T3 (FT3), free T4 (FT4) with elevated thyroid-stimulating hormone (TSH)] - all measurements showing statistical significance (p < 0.05).
Conclusion:
This study provides causal evidence that Bifidobacterium depletion may contribute to goiter development through SCFA-mediated impairment of NIS-dependent iodine uptake and thyroid hormone synthesis, highlighting the association of the "gut-thyroid axis" and laying the foundation for early prevention and therapeutic intervention of goiter.
More Related Videos
Related Concept Videos
01:20Synthesis and Regulation of Thyroid Hormones
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The...
01:23The Thyroid Gland
The follicles have a central cavity lined by simple cuboidal to squamous epithelial cells called follicular cells. These cells produce the glycoprotein...
01:18Functions of Thyroid Hormones
TH is indispensable for the normal development and maturation of the skeletal, muscular, and nervous systems during fetal and childhood growth. It facilitates bone mineral turnover and regulates protein synthesis in developing tissues, contributing significantly to overall growth and...
01:17Hormones and Bone Tissue
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...
01:21Skeleton and Calcium Homeostasis
01:30Inflammatory Bowel Disease III: Diagnostic Studies and Management I-Nutritional Therapy
Diagnostic studies
A colonoscopy is the definitive screening test, distinguishing ulcerative colitis from other colon diseases with similar symptoms. During a colonoscopy test, inflamed mucosa with exudate ulcerations can be observed, and biopsies are taken to determine the histologic characteristics of the...