FOXP3 and colitis: Tao et al. (2007) reported that inhibition of HDAC9 increased the expression of Foxp3+ and number of Treg cells, improving suppressor function of Foxp3+ Treg cells under homeostatic conditions and amplified attenuation of Treg cell-mediated colitis in mice. Some SCFAs such as butyrate and propionate also modulate antigen presentation by inhibiting dendritic cell development through inhibiting HDACs (Bernard et al., 2002; Wang et al., 2008; Singh et al., 2010; Liu L. et al., 2012) and interacting with FFAR (Singh et al., 2010; Arpaia et al., 2013; D’Amelio and Sassi, 2018).