Abstract
BACKGROUND: Hashimoto's thyroiditis (HT) is an autoimmune disease. Recent studies have found that the gut microbiota may play an important role in inducing HT, but there are no systematic studies on the changes in the gut microbiota during the development of HT. METHODS: In this study, 16S rDNA high-throughput sequencing technology in combination with the Kruskal-Wallis test, CCA/RDA analysis, Spearman correlation analysis, and other statistical methods were used to analyze the effects of age, gender, hormones, and other environmental factors on gut microbiota by comparing the differences in the microbiota at different stages of HT development. RESULTS: The results showed that there were differences in the gut microbiota composition between healthy people (HCA) and in patients with HT. Lachnoclostridium, Bilophila, and Klebsiella were enriched in the HCA group, while Akkermansia, Lachnospiraceae, Bifidobacterium, Shuttleia, and Clostriworthdia were enriched in the HT group. Environmental factors analysis revealed that the Bifidobacterium and Klebsiella were two groups of bacteria that have undergone dramatic changes in HCA and HT, and mainly affected by gender. Romboutsia and Haemophilus regulated by the hormone of free triiodothyronine (FT3) may promote the development of HT, while Faecalibacterium and Lachnospiraceae regulated by free thyroxine (FT4) may protect the host. CONCLUSIONS: Comprehensive studies have shown that gender is an important factor affecting gut microbial composition, but with the development of HT, hormones, age, and TSH begin to become dominant factors.