Development of a 5-step multi-chamber reactor as a simulation of the human intestinal microbial ecosystem.

A five-stage reactor was developed to simulate the gastro-intestinal microbial ecosystem of humans. The small intestine was simulated by a two-step "fill and draw" system, the large intestine by a three-step reactor. A representative supply medium was developed to support a microbial community resembling that of the human gastro-intestinal tract. The entire system was validated by monitoring fermentation fluxes and products, i.e. indicator bacterial groups, volatile fatty acids, enzymatic activities and headspace gases. The simulator was operated with varying concentrations and combinations of arabinogalactan, xylan, pectin, dextrins and starch. The resulting patterns of microbial diversity and activity were analysed and compared with data for in-vivo gastro-intestinal microbial communities as described in the literature and found to be representative.