Lactitol controls indole and 3-methylindole production by swine cecal microflora

L-tryptophan is degraded by intestinal microorganisms into 2 alternative volatile lipophilic compounds, indole and 3-methylindole (skatole) which can be responsible for pulmonary oedema and emphysema, and contribute to the unpleasant taste and odor in cooked meat. This research investigated whether the use of sugar beet pulp silage (SBPS) and/or lactitol as energy source can reduce microbial proteolysis and can affect the in vitro intestinal production. SBPS produced a 15% reduction in the ammonia production rate over 24 h and a 34% reduction of indole production rate over the first 16h. Conversely, no difference could be observed on skatole production rate. When lactitol was added to the low fiber (LF, without SBPS) diet indole and skatole production rate were reduced by 20 and 22%, respectively, whereas when lactitol was added to the high fiber diet (HF, with SBPS) indole production rate decreased by 10%, and skatole production rate dropped by 48%. Our results indicate that lactitol may be an interesting additive to control skatole production.