<prompt> Which of the following are absorbed in the Colon?Long chain fatty acidsShort chain Fatty AcidsMedium chain FANone  <response>: Ans. B. Short-chain Fatty Acids. Ref. Harrion 18th Table 294-3 Ganong 23rd pg. 464 466; Ch.27 Short-chain fatty acids SCFAs are produced in the colon and absorbed from it.Comparison of Different Types of Fatty Acids Long-ChainMedium-ChainShort-ChainCarbon chain length128-128Present in dietIn large amountsIn small amountsNoOriginIn diet as triglyceridesOnly in small amounts in diet as triglyceridesBacterial degradation in colon of nonabsorbed carbohydrate to fatty acidsPrimary site of absorptionSmall intestineSmall intestineColonRequires pancreatic lipolysisYesNoNoRequires micelle formationYesNoNoPresence in stoolMinimalNoSubstantial SHORT-CHAIN FATTY ACIDS IN THE COLON Short-chain fatty acids SCFAs are produced in the colon and absorbed from it. SCFAs are two- to five-carbon weak acids that have an average normal concentration of about 80 mmolL in the lumen. About 60 of this total is acetate, 25 propionate, and 15 butyrate. They are formed by the action of colonic bacteria on complex carbohydrates, resistant starches, and other components of the dietary fiber, that is, the material that escapes digestion in the upper GIT and enters the colon. Absorbed SCFAs are metabolized and make a significant contribution to the total caloric intake. In addition, they exert a trophic effect on the colonic epithelial cells, combat inflammation, and are absorbed in part by exchange for H, helping to maintain acid-base equilibrium. SCFAs are absorbed by specific transporters present in colonic epithelial cells. SCFAs also promote the absorption of Na, although the exact mechanism for coupled Na-SCFA absorption. 