Dietary fibre intervention in Hashimoto's thyroiditis patients and its impact on the gut microbiota

This is the authors' abstract. We don't add key points for this paper.

There is currently a lack of effective methods for treating Hashimoto's thyroiditis (HT) patients with normal thyroid function. The microbiota is one of the factors affecting the thyroid gland. Dietary fibre (DF) can promote intestinal health and regulate the gut microbiota. This study evaluated the clinical efficacy of DF in treating HT and further explored the impact of DF on the gut microbiota. To investigate the effects of DF supplementation on HT patients, we conducted a randomized controlled trial (RCT) with 70 patients and an exploratory cohort study with 45 patients (included among the 70 patients in the RCT) with HT to investigate the potential impact of DF on the gut microbiota. After intervention with DF supplements, the antithyroid peroxidase antibody (TPOAb), antithyroglobulin antibody (TgAb), and IL-10 levels decreased, and the thyrotropin (TSH) level increased. However, the differences in Tumor necrosis factor alpha (TNF-α) were not significant. There was no difference in α-diversity or β-diversity. However, in the DF group, the abundances of Xylanophilum and Parabacteroides increased, whereas the abundance of Erysipelatoclostridium decreased. The functional features differed between the two groups. In the DF group, the composition of the DF group microbiota and metabolic functions changed before and after intervention. The gut microbiota of HT patients shares common characteristics, but DF can cause changes in some gut microbiota, which are correlated with several clinical indicators. Thyroid hormones also affect the gut microbiota of HT patients and are associated with several predicted functions. This study was registered in the international traditional medicine clinical trial registry (ITMCTR) (registered code: ITMCTR2024000463) (time of registration: 2024/08/24).