Subsequently, IL-22 positively influences phagocytes, mediating IL-1β production and ultimately elevating IL-17 production in RORγt+ CD4+ T cells (55).Studies have shown that gut microbes exert control over the functionality of Treg cells by producing metabolites, including short-chain fatty acids (SCFAs), providing protection against colitis in mice through a mechanism dependent on Ffar2 (GPR43) (57). The gene discussed is FFAR2; the disease is colitis.