FOXO1 and type 2 diabetes mellitus: TMAO was found to induce endoplasmic reticulum (ER) stress inHEK293 cell lines through activation of protein kinase R-like endoplasmic reticulum kinase (PERK) and forkhead box protein O1 (FoxO1), which may lead to insulinresistance, thereby increasing the risk of hyperglycemia, metabolic dysfunction,and type 2 diabetes in individuals with higher levels of TMAO [35].