Short chain fatty acid produced by bacteria are maximally absorbed in:
Increasing attention is being focused on short-chain fatty acids (SCFAs) that are produced in the colon and absorbed from it. SCFAs are 2–5 carbon weak acids that have an average normal concentration of about 80 mmol/L 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 gastrointestinal tract and enters the colon.
Reference: Ganong’s Review of Medical Physiology T W E N T Y - F I F T H   E D I T I O N page no 483
Duodenum
Colon
Ileum
Jejunum