The Study
Detection of Alterations in the Gut Microbiota and Intestinal Permeability in Patients With Hashimoto Thyroiditis
This study looked at people with Hashimoto’s and people without it, and found that their gut bacteria and eating habits were a little different. But it didn’t change anyone’s diet or bacteria to see if that made Hashimoto’s better or worse — so we can’t say one thing caused the other.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
People with Hashimoto’s thyroiditis have different gut bugs than healthy people — more Bacteroides, less Bifidobacterium — and their gut lining may be leakier. Their diets also tend to have more meat and fewer veggies. Taking thyroid medicine changes some of these bugs.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 544 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — these changes suggest diet and gut health may play a role in how Hashimoto’s develops or worsens, even if they don’t directly cause it.
- 2Patients had 10x more Bacteroides (2,344 vs 221 REU) and 10x less Bifidobacterium (71 vs 831 REU) than healthy people.
- 3Zonulin (a leaky gut marker) was 63% higher in patients (30.9 vs 19.0 ng/ml).
- 4Those not on thyroid medicine had 60x more Lactobacillus than those who were.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Frontiers in Immunology
Year
2021
Authors
Leonardo C. F. Cayres, Larissa Vedovato Vilela de Salis, G. S. Rodrigues, A. Lengert, A. Biondi, L. Sargentini, J. L. Brisotti, Eleni Gomes, G. L. V. de Oliveira
Related Content
Claims (6)
Autoimmune thyroid disease occurs only when genetic predisposition, environmental triggers, and increased intestinal permeability are all present together.
People with Hashimoto thyroiditis consume fewer vegetables, fruits, dairy, and carbohydrates, and more animal-derived proteins than people without the condition.
In Brazilian adults, Hashimoto thyroiditis is associated with higher levels of Bacteroides bacteria and lower levels of Bifidobacterium bacteria in the gut compared to healthy individuals.
People with Hashimoto thyroiditis have higher levels of zonulin in their blood than people without the condition.
In people with Hashimoto thyroiditis, eating more animal-derived protein is linked to lower levels of Bacteroides bacteria in the gut.
People with Hashimoto thyroiditis who are not taking levothyroxine have more Lactobacillus bacteria in their gut than those who are taking levothyroxine.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.