Abstract
This study aims to analyze the differences in gut microbiota of patients with primary hypothyroidism before and after treatment and their correlations with clinical indicators. A total of 20 newly diagnosed primary hypothyroidism patients were selected for the study. These patients were treated with levothyroxine sodium (L-T4) for 12 weeks, and fecal samples were collected before and after treatment. Concurrently, fecal samples from 20 healthy controls were also collected. High-throughput 16sRNA sequencing was conducted to analyze the composition of gut microbiota in each group. At the phylum level, the abundance of Bacteroidetes decreased in patients with primary hypothyroidism. After treatment, the abundance of Bacteroidetes increased, while the abundance of Proteobacteria and Desulfobacterota decreased. At the genus level, the abundance of Bacteroides and Faecalibacterium decreased, while the abundance of Collinsella, Klebsiella, Parabacteroides, and the genus Koalarothia increased. After treatment, the abundance of Streptococcus, Ruminococcusgnavus, Megamonas and Corrococcus increased, while the abundance of Escherichia-Shigella, Agaricus, Ruminococcus torques, Koalarothia, and Blautia decreased. Differential species screening showed 24 different species between the pre-treatment and post-treatment groups. Spearman correlation analysis showed that Streptococcus was positively correlated with TT3, TT4, and FT4, and negatively correlated with AST; R. torques was negatively correlated with TT4 and FT4; Koalarothia was positively correlated with TgAb and TC; Blautia was positively correlated with TPOAb. Patients with primary hypothyroidism exhibit gut microbiota dysbiosis, with a decrease in the abundance of certain short-chain fatty acid-producing bacteria, which increases after treatment. There is a certain correlation between specific gut microbiota and thyroid function as well as lipid metabolism indicators.