Effects of slow liquid transit on colonic fermentation in vitro

The colonic microflora and their fermentation end-products play important roles in host health. The objective of this study was to determine the biochemical responses of colon microflora to slow colonic transit. For this purpose, the study was carried out with the colon simulation technique (Cositec). Inocula and fermentable substrates were obtained from colon contents of slaughtered pigs. To simulate slow colonic transit, the liquid turnover rate in the Cositec system was decreased by ca. %50. Slow liquid turnover resulted in a significant decrease in pH, total short-chain fatty acids (SCFAs), acetate and propionate productions. However, the production of butyrate was not significantly affected by the treatment. The redox potential was affected by slow liquid turnover and became more positive. Organic matter digestibility increased in response to slow liquid turnover. These results indicated that slow liquid turnover altered biochemical milieu within the colon and this may play a key role in the pathogenesis of colorectal diseases.