Molecular Alteration Analysis of Human Gut Microbial Composition in Graves’ disease Patients Original paper
Researched by:
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Karen Pendergrass
ID
Karen Pendergrass
Karen 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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Karen Pendergrass
Researched by:
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Karen Pendergrass
ID
Karen Pendergrass
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.
Karen Pendergrass
Location
China
Sample Site
Feces
Species
Homo sapiens
What was studied?
This study investigated alterations in the intestinal microbiota composition of patients with Graves’ disease (GD) to explore possible microbiome signatures associated with the condition. The researchers used a combination of denaturing gradient gel electrophoresis (DGGE), real-time PCR, and high-throughput 16S rRNA gene sequencing (V3–V4 region) to compare microbial diversity, composition, and abundance in GD patients versus healthy controls. The study aimed to evaluate both qualitative and quantitative differences in gut microbiota and determine whether dysbiosis may be implicated in GD pathogenesis.
Who was studied?
The study analyzed fecal samples from 27 GD patients (10 males, 17 females, aged 35–50) and 11 healthy age- and sex-matched controls (4 males, 7 females). All GD patients had a disease duration of 1.5 years and were medication-free for at least six months before sampling. None of the participants had recent antibiotic, probiotic, or prebiotic use. Samples were collected at Xi’an Jiaotong University’s affiliated hospital and processed under strict ethical guidelines.
Most important findings
Graves’ disease patients exhibited reduced gut microbial diversity, evidenced by significantly lower richness indices (Observed Species, Chao1, ACE, and Good’s coverage) compared to controls, although Shannon and Simpson indices were not statistically different. The most pronounced alterations were seen in specific taxa:
| Taxonomic Level | Increased in GD | Decreased in GD |
|---|---|---|
| Phyla | Bacteroidetes, Proteobacteria | Firmicutes (trend) |
| Family | Prevotellaceae, Pasteurellaceae | Enterobacteriaceae, Veillonellaceae, Rikenellaceae |
| Genus | Prevotella_9, Haemophilus | Alistipes, Faecalibacterium |
| Species | Haemophilus parainfluenzae (↑) | Bifidobacterium longum, Lactobacillus gasseri, Clostridium leptum (↓)Molecular Alteration An… |
Real-time PCR confirmed significantly reduced copy numbers of Bifidobacterium and Lactobacillus in GD (P <0.05), suggesting depletion of beneficial microbes. Meanwhile, Bacteroides vulgatus was slightly increased, and Clostridium leptum slightly reduced, although these changes did not reach significance by q-value correction.The dominant microbial phyla in GD were Bacteroidetes (57.6%) and Firmicutes (32.9%), with GD patients having a lower Firmicutes: Bacteroidetes ratio compared to controls.
Key implications
This study reveals that Graves’ disease is associated with a distinct gut microbiota signature characterized by reduced microbial richness and altered abundances of both beneficial and potentially pathogenic taxa. The significant increase in Haemophilus parainfluenzae and Prevotella_9, along with the depletion of Faecalibacterium and Alistipes, suggests immune-related microbial imbalance. These taxa may serve as major microbial associations (MMAs) for GD and could be investigated as microbial targets for microbiome-based interventions. The depletion of Lactobacillus and Bifidobacterium also suggests potential for probiotic or prebiotic therapy. While causality remains unresolved, the findings reinforce the need to consider intestinal dysbiosis as a contributing factor in GD pathogenesis and therapy development.
Microbiome Signatures Definition: A Conceptual Advancement for Translational Microbiome Science
Microbiome signatures are reproducible ecological and functional patterns—encompassing traits, interactions, and metabolic functions—that reflect microbial adaptation to specific host or environmental states. Beyond taxonomy, they capture conserved features like metal metabolism or immune modulation, enabling systems-level diagnosis and intervention in health and disease.