Intestinal Microbiota Changes in Graves’ Disease: Microbial Signatures and Clinical Impact 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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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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Fact-checked by:
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Karen Pendergrass
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Karen Pendergrass
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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 study investigated the intestinal microbiota composition and diversity in patients with Graves’ disease (GD) compared to healthy controls, aiming to identify specific microbial changes associated with GD. The research addresses the knowledge gap regarding how autoimmune thyroid dysfunction may alter gut microbiota, potentially influencing disease pathogenesis and progression. The focus keyphrase, “intestinal microbiota changes in Graves’ disease,” is central to the study, as the authors performed high-throughput 16S rRNA gene sequencing on fecal samples to comprehensively profile and compare the gut microbial communities between the two groups. By elucidating these microbial signatures, the study provides foundational data for understanding the interplay between gut bacteria and autoimmune thyroid disease.
Who was studied?
The study included 39 patients with newly diagnosed, untreated Graves’ disease (GD) and 17 healthy controls, all recruited from Beijing Haidian Hospital, China, between April and December 2017. The GD group comprised 11 males and 28 females, aged 15–67 years, while the control group included 6 males and 11 females, aged 13–62 years, and was matched for age, sex, and body mass index. Both groups excluded individuals with a history of gastrointestinal diseases, recent antibiotic or prebiotic use, hormonal medication, Chinese herbal medicine, pregnancy, smoking, or excessive alcohol consumption. All participants adhered to a light diet for one week prior to fecal sampling to minimize dietary confounding. Diagnosis of GD followed established Chinese Society of Endocrinology criteria, ensuring a well-defined study population.
Most important findings
The major findings revealed a marked reduction in microbial diversity (both richness and evenness) in GD patients compared to healthy controls, as assessed by Chao1 and Shannon diversity indices. Beta-diversity analyses (PCoA, NMDS, PCA, and PLS-DA) demonstrated clear separation between the microbiota profiles of GD patients and controls, indicating significant compositional shifts. Linear discriminant analysis effect size (LEfSe) pinpointed specific taxa altered in GD: Bacilli, Lactobacillales, Prevotella, Megamonas, and Veillonella were significantly increased in GD patients, whereas Ruminococcus, Rikenellaceae, and Alistipes were decreased. These taxa changes suggest a dysbiotic state characterized by expansion of potentially pro-inflammatory or immune-modulating bacteria and loss of genera often associated with gut health and metabolic regulation. The increased abundance of Prevotella, in particular, may have implications for immune modulation and drug responsiveness, while decreased Ruminococcus and Alistipes have been linked to other autoimmune and inflammatory conditions. These microbial shifts represent a distinct intestinal microbiota signature for GD, relevant for inclusion in a microbiome signatures database.
Key implications
The study’s findings underscore a significant association between Graves’ disease and gut microbiota dysbiosis, marked by decreased diversity and characteristic alterations in microbial taxa. These changes may contribute to or reflect underlying immune dysregulation in GD and could influence disease activity, response to therapy, or development of comorbidities. The identification of specific bacterial changes provides potential biomarkers for GD diagnosis or monitoring and highlights new avenues for investigating microbiota-targeted interventions, such as probiotics or dietary modification, in autoimmune thyroid disorders. However, as a cross-sectional study, causality cannot be established, and results may be influenced by regional dietary patterns. Further longitudinal and mechanistic studies are needed to clarify the causal links and therapeutic potential of modulating the gut microbiome in GD.