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Controlled Feeding Experiment (CaFE)

This study has been completed.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Information provided by (Responsible Party):
James Lewis, University of Pennsylvania Identifier:
First received: August 3, 2009
Last updated: June 22, 2013
Last verified: June 2013
The purpose of this study is to determine the effect of dietary fat, in standard formulation, on the composition of the human microbiome in a prospective study of normal volunteers. Participants will be randomly assigned to either a high fat or low fat diet for 10 days. The gut microbiome will be phylotyped in fecal samples as well as in bacteria adherent to the colonic mucosa prior to, and during the course of the dietary interventions.

Condition Intervention
Effect of Diet on Microbiome Composition
Other: High fat diet

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: Controlled Feeding Experiment of High and Low Fat Diet and Stool Microbiome Controlled Feeding Experiment of High and Low Fat Diet and Stool Microbiome Composition

Further study details as provided by University of Pennsylvania:

Primary Outcome Measures:
  • This is not an efficacy study. There is no pre-specified clinical endpoint for this study. Rather, the outcome is the composition of the gut microbiome. [ Time Frame: 10 days ]

Enrollment: 10
Study Start Date: July 2009
Study Completion Date: August 2011
Primary Completion Date: January 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
High Fat Low Fiber Diet Other: High fat diet
High fat diet and low fat diet are composed of the same food, but the portion sizes are varied.
Low Fat High Fiber Diet Other: High fat diet
High fat diet and low fat diet are composed of the same food, but the portion sizes are varied.


Ages Eligible for Study:   18 Years to 40 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  1. Participant is capable of giving informed consent
  2. Participant is age 18 to 40 years

Exclusion Criteria:

  1. Diagnosis with Inflammatory bowel disease (IBD), celiac disease, or other chronic intestinal disorders.
  2. Baseline bowel frequency less than every 2 days or greater than 3 times daily.
  3. Current smoker.
  4. Body Mass Index (BMI) <18.5 of >35.
  5. Diabetes mellitus (DM)
  6. Diagnosis with coronary artery disease, congestive heart failure, or prior myocardial infarction.
  7. History of dyslipidemia or receiving treatment for hypercholesterolemia. This will be defined as a fasting LDL >160 mg/dL or a non-fasting total cholesterol >200 mg/dL or non-fasting HDL<40 mg/dl. Additionally, patients receiving drug therapy for hypercholesterolemia will be excluded.
  8. Prior bowel resection surgery.
  9. Contraindication to flexible sigmoidoscopy and biopsies. Patients with suppressed white blood count may be at increased risk of systemic infection following sigmoidoscopy with biopsies. As such, subjects with a white blood cell (WBC) count less than 3,500 or an absolute neutrophil count of less than 1,000 will be excluded. Patients with thrombocytopenia or with a coagulopathy may be at increased risk of bleeding complications after colonoscopic biopsies. As such, patients with a platelet count of less than 100,000 or an international normalized ratio (INR) greater than 1.2 will be excluded from the study.
  10. Student or employee of any one of the investigators.
  11. Pregnant women.
  12. Use of antibiotics in the prior 6 months.
  13. Use of antacids, non-steroidal anti-inflammatory drugs (NSAIDs), or dietary supplements in the preceding 2 weeks.
  14. Use of any of the following medications in the 4 weeks prior to randomization: proton pump inhibitors (PPI), histamine receptor antagonists, narcotics, tricyclic antidepressants, anticholinergics (e.g., hyoscamine), metoclopramide, anti-diarrhea medications, laxatives.
  15. HIV infection, AIDS, or other known conditions resulting in immunosuppression.
  16. Allergies or intolerance to the components of the study diets.
  17. Participant has experienced diarrhea within the two weeks prior to the first sigmoidoscopy. Diarrhea is defined as a change in bowel habits with an increased frequency or loose stools such that the stool could not be lifted with a fork.
  18. Any condition that the investigator feels may limit the volunteer's ability to complete the study protocol.
  Contacts and Locations
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Please refer to this study by its identifier: NCT00951756

United States, Pennsylvania
University of Pennsylvania
Philadelphia, Pennsylvania, United States, 19104
Sponsors and Collaborators
James Lewis
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Principal Investigator: James D Lewis, MD, MSCE University of Pennsylvania
  More Information

Responsible Party: James Lewis, Professor of Medicine and Epidemiology, University of Pennsylvania Identifier: NCT00951756     History of Changes
Other Study ID Numbers: DK83981
UH2DK083981 ( US NIH Grant/Contract Award Number )
Study First Received: August 3, 2009
Last Updated: June 22, 2013

Keywords provided by University of Pennsylvania:
Dietary fat
Microbiome composition
Controlled feeding experiment processed this record on May 22, 2017