Functional Research of Emulsifiers in Humans
Condition: Healthy
Study type: Interventional

Summary: 
      A randomized double-blind study of the effect of carboxymethylcellulose (CMC) on stool
      microbiota composition, microbiota localization, and metabolic parameters in healthy
      subjects. It includes a 11-day in-patient stay, randomization to an emulsifier-free group or
      a CMC group with the same diet except baked goods/sorbet with added CMC at 15g/person/day.
    

Detailed description: 
      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.
    

Intervention name(s): Emulsifier-containing diet
Intervention type(s): Other
Intervention description(s): CMC is one of many synthetic dietary emulsifiers that are incorporated into a variety of processed foods. We have recently shown that, in mice, consumption of P80 and CMC, alters microbiota composition, have pro-inflammatory potential and promote microbiota encroachment into the colonic mucosa, low-grade inflammation, and metabolic syndrome. However, it is not known whether these compounds have similar effects in humans. We would like to study these effects in the human gut microbiota.
Other intervention name(s): Carboxymethylcellulose (CMC)
Intervention MeSH terms: Carboxymethylcellulose Sodium
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Other