ABSORPTION OF SHORT-CHAIN FATTY-ACIDS IN HUMAN STOMACH AND RECTUM

Increased interest in the metabolism and therapeutic potential of short-chain fatty acids (SCFA) prompted this study of the absorption rates of acetate, propionate, and butyrate in the human rectosigmoid, and in the human stomach. In human rectosigmoid, all SCFA were absorbed from neutral infusates, but propionate and butyrate absorption exceeded that of acetate. In human stomach, acetate was absorbed in the protonated form only, and butyrate was absorbed at a faster rate than acetate. These observations are compatible with both popular models of SCFA absorption: non-ionic diffusion, and carrier-mediated anionic exchange.