Figure 2.

Short-chain fatty acids in the large intestine have important local and systemic biological functions. (A) Acetic, propionic, and butyric acid are the three most abundant SCFAs in the large intestine, where they are synthesized by the gut microbiota from dietary fiber. (B) Schematic representation of the butyrate paradox. Butyric acid creates a colonic lumen-to-crypt decreasing concentration gradient, which promotes the growth or decreases the proliferation of healthy colonocytes, but selectively inhibits undifferentiated cells, such as cancer cells and stem cells, by mechanisms that include epigenetic changes. Created with BioRender.com.