Simulation of the mucosal environment in the re-construction of the synthetic gut microbial ecosystem

Human gut surface-attached mucosal microbiota plays significant roles in human health and diseases. This study sought to simulate the mucosal environment using mucin-agar gel and synthetic mucosal microbial community in vitro. To select suitable culture media, microbial communities were assembled and cultured in seven different media at 37 °C for 36 h. Among the seven media, Bryant & Burkey (BB) and Gifu Anaerobic Media (GAM) were selected considering their microbial biomass and bacterial composition. The communities were again assembled and cultured in these two media with mucin-agar. The results showed that some bacterial genus such as Bifidobacterium, Collinsella, and Roseburia could efficiently colonize in the solid mucin-agar part while Enterococcus, Clostridium, and Veilonella dominated in the liquid part. Metabolic functional prediction for the microbial community in each medium part showed that the gene expression involved in metabolism and cell motility pathways were distinctively differentiated between the liquid and solid medium part, and the functional potential was highly related to the microbial composition. The current results demonstrate that the simulation of the gut microbial ecosystem in vitro can be beneficial to the mucosal environment mimicking and the study on the mechanistic potential of the human gut microbiota for easy translation of microbiome research to therapies.