Development of a four species biofilm to mimic the upper gut microbial community

Abstract

Abstract The human gut microbiome is a dynamic ecosystem of microorganisms, influenced by numerous disparate factors including diet, age, and lifestyle. Investigating how changes in these variables affect the microbial gut community is limited due to the high variability found between individuals’ microbiota and limits inherent in sampling methodologies. Here we developed a microbial community with a defined species content - Lactocaseibacillus rhamnosus, Streptococcus salivarius, Enterococcus faecalis, and Bifidobacterium bifidum – mimicking the microbiota present in the small intestine. The biofilm community reached a steady state within 5–6 days of culture in a semi-batch system and once harvested and re-inoculated into a new reactor, the steady state was re-established within 24 hours. Biofilm development, microcolony structure, viability, and biomass were determined. Overall, this new “mock” community system can accurately mimic the small intestine microbiota and provide a platform to study community changes that occur due to environmental and chemical factors and lead to dysbiosis.