Graves’ Disease Gut Microbiota: Microbial Signatures and Immune Correlations in Chinese Patients Original paper
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Giorgos Aristotelous
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Giorgos Aristotelous
Read MoreGiorgos — BSc, MSc. Giorgos is an exercise scientist whose training and professional practice sit at the intersection of human performance, clinical health, and emerging microbiome science. He holds a BSc in Sports Science & Physical Education from Aristotle University (2012) and an MSc in Exercise & Health from Democritus University (2016), where his graduate work explored physiological adaptations to training across the lifespan. Now in his 15th year of practice, Giorgos pairs evidence-based coaching (ACSM-CPT, NSCA, USA Weightlifting) with a research-driven interest in how physical activity, body composition, and musculoskeletal integrity shape—and are shaped by—host–microbiome dynamics.
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Karen Pendergrass
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Karen Pendergrass
Read MoreKaren Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease—four years before the first published case study.
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Giorgos Aristotelous
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Researched by:
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Giorgos Aristotelous
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Giorgos Aristotelous
Read More
Fact-checked by:
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Karen Pendergrass
ID
Karen Pendergrass
Read More
Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
Giorgos Aristotelous
What was studied?
This study investigated the associations between gut microbiota composition and thyroidal function status in Chinese patients with Graves’ disease (GD), an autoimmune hyperthyroid condition. The primary aim was to determine whether specific alterations in gut microbiota correlate with clinical characteristics and immune markers, particularly thyrotropin receptor antibody (TRAb) levels, in GD patients. Using 16S rDNA high-throughput sequencing of fecal samples, the researchers compared gut microbiota profiles among three groups: untreated GD patients, healthy volunteers, and GD patients after anti-thyroid treatment with Methimazole. The study focused on identifying microbial signatures linked to the disease state and treatment response, thereby providing potential biomarkers for GD and insights into the pathogenesis of the disease.
Who was studied?
The study included 15 patients newly diagnosed with primary Graves’ disease (HG), 14 healthy, age- and sex-matched volunteers (CG), and 13 of the GD patients re-sampled after 3–5 months of anti-thyroid drug therapy (TG). All participants were from Jiangsu Province, China, had similar dietary backgrounds, and were screened to exclude confounding factors such as other autoimmune or metabolic diseases, recent antibiotic use, gastrointestinal surgery, and major organ dysfunction. None had a history of long-term hormone therapy, and pregnant or lactating women, vegetarians, and individuals with a history of substance abuse were excluded. This careful selection ensured the observed microbiome differences were attributable primarily to Graves’ disease and its treatment.
Most important findings
The study found significant dysbiosis in the gut microbiota of GD patients compared to healthy controls. Alpha diversity indices (Shannon, Simpson, and observed OTUs) showed marked reductions in GD patients, indicating decreased microbial diversity and richness, which partially recovered after anti-thyroid therapy. At the genus level, Lactobacillus, Veillonella, Streptococcus, Blautia, and Ruminococcus were significantly enriched in untreated GD patients, while Phascolarctobacterium and Synergistetes were depleted. After treatment, a notable increase in Phascolarctobacterium and decreases in Streptococcus, Blautia, and Ruminococcus were observed.
Microbial associations with clinical markers were particularly striking. TRAb levels—a key immune marker of GD—were positively correlated with Lactobacillus and Ruminococcus, and negatively correlated with Synergistetes and Phascolarctobacterium. Synergistetes abundance was also inversely related to other thyroid autoantibodies (TPOAb and TGAb), suggesting a possible protective or regulatory role. The observed increase in potentially pro-inflammatory genera (e.g., Veillonella, Streptococcus) and reduction in SCFA-producing, possibly anti-inflammatory genera (e.g., Phascolarctobacterium, Synergistetes) highlight a disrupted intestinal immune environment in GD.
Key implications
This study provides evidence that Graves’ disease is characterized by significant alterations in gut microbiota composition, with specific genera showing robust associations with disease activity and immune parameters such as TRAb. The enrichment of Ruminococcus and Lactobacillus, along with depletion of Synergistetes and Phascolarctobacterium, may influence or reflect the immune dysregulation underlying GD. These findings suggest that certain gut microbial profiles could serve as potential biomarkers for GD activity or therapeutic response and provide targets for microbiome-based interventions. However, causality cannot be inferred from this cross-sectional and observational design; further longitudinal and mechanistic studies, including animal models, are needed. Still, this study advances our understanding of the gut–thyroid axis and opens the door for integrating microbiome signatures into the clinical management of Graves’ disease.