Functional Research of Emulsifiers in Humans

This is a randomized double-blind, controlled feeding experiment examining the effect of CMC on the stool microbiota composition, gene expression, and microbiota localization with respect to the epithelium. In addition, the investigators will assess the impact of CMC exposure in the diet on markers of metabolic syndrome including response to oral glucose tolerance testing and other plasma metabolite measurements. Sixteen healthy volunteers were be recruited. 3 were admitted for 17 days and 13 participants were admitted for an 11-day in-patient study. All participants received 3 full days of freshly prepared emulsifier-free food to begin the study. This will be called the "washout period". Those will a 17 day stay received the wash out diet while inpatient and those with an 11 day stay received the wash out dies while out patient. Participants will then be randomized into an "emulsifier-free" arm and a "CMC" arm in a 1:1 ratio. Both arms will continue the same diet except that the "CMC" arm's brownie and sorbet will have CMC added to achieve a level of 15 gm per person per day consumption. Serial collection of fecal, plasma, urine and mucosal biopsy samples will be performed to investigate the extent to which CMC consumption by humans impacts the gut microbiota and its interaction with the host parameters related to inflammation and metabolism. Participants will have daily urine and stool collections. Sigmoidoscopies and glucose tolerance testing will be completed on the day prior to the start of the intervention and the last day of the inpatient stay (Days 4 and 17 for the 3 participants with a 17 day stay and days 1 and 11 for participants with an 11 day stay. Blood samples were collected on days 1-4, 5, 8, 10, 12, 15, and 17 for those with a 17 day inpatient stay and 1-4, 8, 10, and 11 for those with an 11 day stay.