INS and Impaired glucose tolerance: Treg cells in VAT are important in the regulation of adipose tissue inflammation and insulin sensitivity.[9] Specifically, ST2+ Treg cells, a Treg subset with high PPARγ expression in VAT, exhibit a more activated phenotype than ST2− Treg cells.[8, 24] Loss of ST2 expression in VAT Treg cells leads to impaired glucose tolerance.[25] Here, we demonstrate that gut microbiota is essential for the maintenance of ST2+ Treg cells in VAT, which is associated with the abundance of butyrate‐producing bacteria.