Gut Microbiome Associated With Graves Disease and Graves Orbitopathy: The INDIGO Multicenter European StudyOriginal paper
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.
Read MoreWhat was studied?
Researchers compared fecal microbiota in 105 Graves disease (GD) patients, including those with Graves orbitopathy (GO) of varying severity, against 41 healthy controls across four European countries.
How was it studied?
The INDIGO study used an observational design with both cross-sectional and longitudinal components, sampling patients while hyperthyroid and TRAb positive, then following bacterial associations with TRAb persistence over 200 days of antithyroid drug treatment.
What did they find?
Actinobacteria were increased and Bacteroidetes decreased in GD and GO patients versus controls, raising the Firmicutes to Bacteroidetes ratio. Fifteen genera differed in abundance, most skewed in mild GO, and Bacteroides correlated positively with TSH and negatively with free thyroxine. Clostridiales present at diagnosis correlated with TRAb persisting past 200 days.
Why it matters
The elevated Firmicutes to Bacteroidetes ratio mirrored findings in a TSHR-immunized mouse model, distinguishing autoimmunity-related microbiome changes from those due to hyperthyroidism alone. Identifying Clostridiales at diagnosis could flag patients at risk of TRAb persistence and relapse.