Graves’ Disease Gut Microbiota Signatures: Key Microbial Shifts and Clinical Implications 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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Kimberly Eyer
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Kimberly Eyer
Read MoreKimberly Eyer, a Registered Nurse with 30 years of nursing experience across diverse settings, including Home Health, ICU, Operating Room Nursing, and Research. Her roles have encompassed Operating Room Nurse, RN First Assistant, and Acting Director of a Same Day Surgery Center. Her specialty areas include Adult Cardiac Surgery, Congenital Cardiac Surgery, Vascular Surgery, and Neurosurgery.
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Autoimmune Diseases
Autoimmune Diseases
Autoimmune disease is when the immune system mistakenly attacks the body's tissues, often linked to imbalances in the microbiome, which can disrupt immune regulation and contribute to disease development.
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Graves Disease
Graves Disease
OverviewGraves’ Disease (GD) affects approximately 0.5% of the population, predominantly women. First-line treatment options—antithyroid medications, radioactive iodine, and surgery— often result in significant side effects, incomplete remissions, and frequent relapses. Further, current first-line treatment options focus on symptoms management, and reflect an inadequate understanding of the etiology of the condition. However, recent research reveals a […]
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Giorgos Aristotelous
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Researched by:
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Giorgos Aristotelous
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Giorgos Aristotelous
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Kimberly Eyer
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Kimberly Eyer
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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 original research article investigated the alterations in gut microbiota composition among patients with Graves’ disease (GD), a systemic autoimmune thyroid disorder characterized by hyperthyroidism. The study aimed to characterize and compare the gut microbial communities of GD patients and healthy controls using 16S rRNA gene sequencing. It sought to identify specific microbial taxa associated with GD and examine their relationship with clinical parameters of thyroid function, such as free thyroxine (FT4), thyrotropin (TSH), and thyroperoxidase antibody (TPOAb) status. The researchers also evaluated whether microbiome signatures could serve as potential biomarkers to distinguish GD patients from healthy individuals.
Who was studied?
The study population comprised 55 patients previously diagnosed with GD and 48 age-, sex-, and body mass index-matched healthy controls, all recruited from Chang Gung Memorial Hospital in Taiwan between October 2017 and March 2020. GD diagnosis was based on clinical features and laboratory criteria—including symptoms of thyrotoxicosis, diffuse goiter, ophthalmopathy, abnormal thyroid function tests, and positive TSH receptor autoantibodies. The healthy controls had normal thyroid function and no history of thyroid disease. Both groups were screened to exclude confounding conditions (e.g., recent antibiotic use, gastrointestinal disorders, other autoimmune diseases). Fecal samples were collected from all participants for microbiota analysis.
Most important findings
A total of 11.7 million sequencing reads were analyzed, yielding 684 operational taxonomic units (OTUs) in the GD group and 671 in controls, with similar richness and diversity between groups. However, principal coordinate and discriminant analyses revealed significant differences in overall community structure (ANOSIM p <0.001). Key microbiome shifts in GD patients included a decreased relative abundance of Firmicutes and increased Bacteroidetes and Actinobacteria at the phylum level. Notably, families such as Prevotellaceae and Veillonellaceae and the genus Prevotella_9 were enriched in GD patients, whereas Lachnospiraceae, Ruminococcaceae, Faecalibacterium, and Lachnospira were more abundant in healthy controls. Metagenomic profiling identified 22 significantly altered bacterial taxa. Many GD-enriched taxa, including Prevotella_9, Parabacteroides, Collinsella, and Actinomyces_odontolyticus, showed strong positive correlations with TPOAb and FT4, and negative correlations with TSH. Conversely, taxa enriched in controls, such as Faecalibacterium and Lachnospiraceae NK4A136 group, showed the opposite pattern. A random forest model based on predominant taxa achieved an area under the curve (AUC) of 0.825, indicating these microbial features could effectively differentiate GD patients from controls.
Key implications
This study demonstrates that while overall gut microbial diversity remains unchanged, the taxonomic composition in GD patients is significantly altered, featuring a distinct microbial signature. The enrichment of pro-inflammatory taxa (such as Prevotella_9 and Veillonellaceae) and the reduction of anti-inflammatory butyrate producers (like Faecalibacterium and Lachnospiraceae) suggest a potential role of gut dysbiosis in GD pathogenesis. These findings highlight the gut microbiota as a possible contributor to, or biomarker of, autoimmune thyroid disease. The strong association between specific microbial taxa and thyroid-related clinical parameters underscores the potential for microbiome-based diagnostics or therapeutics in GD. However, causality cannot be established, and further longitudinal and functional studies are warranted to clarify the mechanistic links and clinical utility.