Validation of the Simulator of the Human Intestinal Microbial Ecosystem (SHIME) Reactor Using Microorganism-associated Activities

The recently developed SHIME reactor (Simulator of the Human Intestinal Microbial Ecosystem) was validated by analysing a number of microorganism-associated activities. Data from the reactor were compared with values from the literature and results obtained from the analysis of faecal material of eight healthy persons. The fermentation patterns of four polysaccharides were studied. Arabinogalactan, xylan and pectin gave fermentation patterns in vitro indistinguishable from in vivo. Five different enzymatic activities were compared with in vivo experiments. All had activities which were of the order of those observed in vitro. The pro-drug sulphasalazine, whose active compound is released through microbial modification in the large intestine, was used as a reference compound. A fair correlation between in vivo and in vitro was found for the latter transformation. In addition the effect of Lactobacillus plantarum on the autochthonous microbial populations was investigated. Administration of L plantarum resulted in an in vitro decrease in gram-negative anaerobic bacteria and total anaerobes. The same effect has been reported in vivo. The results obtained by the various validation experiments indicate that the reactor can be used to study the microbial communities of the gastrointestinal tract.