Effect of short-chain fatty acids on the growth of Salmonella typhimurium in an in vitro system.

Previous studies have revealed a reduction of cecal Salmonella carriage from feeding either carbohydrate or short-chain fatty acids (SCFAs). This in vitro study presents a profile of the relative SCFA content of the ceca when chicks are fed an unmedicated diet with 2.5% carbohydrate. Subsequent incorporation of these acids into culture medium was used to demonstrate their antagonistic activity toward in vitro growth of Salmonella typhimurium. Commonly found concentrations of SCFAs based upon the above findings reduced in vitro Salmonella growth by at least 50%, and 10 x concentrations inhibited growth more than 80%. An explanation of the mechanism(s) involved in growth reduction is offered.