An in-vitro upper gut simulator for assessing continuous gas production: A proof-of-concept using milk digestion

Abstract

Using gases as biomarkers is receiving increasing attention across the field of gut health. The use of in-vitro digestion systems that measure gas is common to understand some of the complex systems that create these gases and previously have been conducted using long time period sampling schemes which miss important signatures regarding the dynamics of gas production. Here the development of a mono-compartment in-vitro digestion simulator capable of recording vital dynamic information in real-time including: CO2 concentration; high sensitivity H2 concentration; and pH are presented and validated utilising milk. The impact of a simplified bacterial model, bacterial population size and the presence of lactase are investigated. The favourable gas production outcomes are obtained when lactase is present, at 106 CFU of bacteria, in good agreement with clinical observations. This proof-of-concept system demonstrates reliable and repeatable results and has the potential to enhance the information capacity of current and future in-vitro simulators.