Prevotella Intermedia Aggravates Subclinical Hypothyroidism

To verify the pathogenicity of P. intermedia in SCH, and preliminarily explore the possible mechanism. The SCH mouse model with oral application of P. intermedia was established, and the variance in the mouse oral microbiota and changes in thyroid function and metabolism were detected in mice. Local immune cell changes were also detected. Student’s t test and analysis of variance were used for statistical analysis. Oral application of Prevotella intermedia changed the composition of oral microbiota of SCH mice, which enhanced the damage to the thyroid and decreased the expressions of functional genes of thyroid. Moreover, Prevotella intermedia decreased the oxygen consumption and aggravated glucose and lipid metabolism disorders in the SCH mice. Mechanistically, Prevotella intermedia increased the proportion of CD4+ T cells in cervical lymph nodes and thyroids in SCH mice. Th1 cells were suggested as playing an important role in the pathogenesis of SCH involving Prevotella intermedia. Prevotella intermedia aggravated SCH manifestations, including thyroid dysfunction and glucose and lipid metabolism disorders, by causing immune imbalance in mice. This study shed new light on the pathogenesis of SCH from the perspective of oral microbiota.