Alteration of Intestinal Microbiota and Hydrogen Sulfide Metabolism in Patients with Hashimoto's Thyroiditis

OBJECTIVE: To analyze the intestinal microbiota and H2S levels in patients with HT. METHODS: Twenty euthyroid HT patients and twenty healthy control individuals were recruited. Fecal samples were collected, and the microbiota was examined using 16S RNA gene sequencing. We also collected serum samples to examine the H2S levels. RESULTS: Compared with patients with HT, the ACE and Chao indices were significantly lower in healthy controls (P=0.04, 0.03, respectively). The microbial composition of the HT group differed significantly from that of the healthy group. We observed a significant increase in the proportions of Bacteroides, Fusobacterium, Sutterella, and Veillonella in patients with HT (P < 0.05). Linear discriminant analysis and effect size analysis also revealed that Bacteroides and Ralstonia were enriched in patients with HT. Additionally, patients with HT had significantly lower H2S levels than healthy controls (P < 0.005). The enrichment of H2S anabolism was linked to the alteration of intestinal microbiota in patients with HT. CONCLUSION: We demonstrated that patients with HT have aberrant intestinal microbiome and that H2S anabolism may contribute to HT pathogenesis.