The study of fiber or prebiotic intake and of microbial metabolites require specialized laboratory instruments that allow us to gather data on these variables. The David Lab uses a high-pressure anion-exchange (HPAE) chromatograph, a type of high-performance liquid chromatography instrument, to analyze carbohydrates and their breakdown products. This allows us to monitor the breakdown of prebiotics, such as inulin, over time in our artificial gut system. The HPAE can also be used to determine composition of prebiotic supplements and other food sources. Additionally, the David Lab has a gas chromatograph that we use to quantify the concentrations of short-chain fatty acids, such as butyrate, both in stool and in our artificial gut system.