The application of a semi-continuous colon simulation technique (Cositec) for studying the effects of clindamycin on microbial hindgut metabolism.

The semi-continuous colon simulation technique was used as an experimental in vitro model to study potential effects of clindamycin application on basic parameters of microbial hindgut metabolism. Hindgut contents from fistulated pigs kept on conventional diets were used as substrates for incubation. Measurements on reproducibility demonstrated the colon simulation technique as a suitable in vitro method to characterize microbial hindgut metabolism and those factors potentially influencing microbial fermentation. Application of clindamycin resulted in disturbances of microbial steady state metabolism and time- and dose-dependent decreases of SCFA production rates with significant reductions of molar butyrate proportions to almost zero. These effects can be related to the onset of functional disturbances of hindgut function under in vivo conditions since butyrate is an essential trophic factor for colonocytes. In addition, clindamycin induced increases in lactate production with a shift towards D-lactate. The relevance of these changes for hindgut function have to be elucidated in further experiments.