CoMiniGut– a small volume in vitro colon model with increased throughput. CoMiniGut- in vitro colon model

With the growing understanding of the influence of gut microbiota (GM) composition and function on human health and disease, there is also a rapidly increasing interest in understanding how dietary components, pharmaceuticals and pre- and probiotics influence GM. In vitro colon models represent an attractive tool for this, but the usefulness of existing models is generally hampered by large working volumes and relatively low throughput. With the dual objective of facilitating the investigation of rare and expensive compounds, as well as an increase of throughput, we have developed a prototype in vitro colon model with a working volume of only 5 ml. The Copenhagen MiniGut CoMiniGut prototype consists of multipla of five parallel single vessel stirred, anaerobic reactor units, which are pH and temperature monitored and controlled. Multiples of five reactors can be added to increase the numbers of biological and technical replicates, allowing e.g. the investigation of interpersonal variations in GM dynamics and acquisition of data with enhanced statistical inference. The proximal, transverse and distal regions of the colon are simulated over time in the individual reactors through an automated pH control set-up. The functionality of CoMiniGut was demonstrated in experiments using 1% (w/v) inulin or lactulose as substrate and fecal inocula from two healthy adult donors. Investigations of microbial community composition dynamics in the MiniGut reactors by MiSeq-based 16S rRNA gene amplicon high throughput sequencing, showed high experimental reproducibility and allowed to extract significant differences in gut microbial composition after 24h of fermentation of inulin and lactulose for both fecal donors. Further, significant inter-individual differences were identified also in the SCFA profiles of the individual donors and fermentates.