Linear regression analysis showed that serum zonulin levels had a significant positive association with the abundance of Prevotella copri (R2 = 0.752, B = 0.520, p = 0.017) and a significant negative association with the abundance of Bifidobacterium (R2 = 0.752, B = −1.041, p < 0.001) in the pSS patients. This evidence concerns the gene HP and peeling skin syndrome.