SCFAs: The Enigma of Weak Electrolyte Transport in the Colon.

Short-chain fatty acids are the predominant luminal anions in the colon (>75 mM) and thus create a rather unique environment for transporting epithelium. The colon absorbs short-chain fatty acids, either by diffusion of the protonated species across the apical membrane or by an anion exchange process with bicarbonate. Additionally, short-chain fatty acids modulate Na absorption, Cl secretion, intracellular pH, and cell volume.