Reproducibility of a Fecal Occult Blood Test Device for Gut Microbiota Analyses
Condition: Normal Physiology
Study type: Observational

Summary: 
      Background:

      - Bacteria and other micro-organisms in the intestines play important roles in immunity and
      other health conditions. As a result, these micro-organisms are likely to affect many health
      conditions, including several types of cancer. Because cancer and other diseases may affect
      the digestive system and the bacteria within it, fecal samples that are taken both before and
      after the onset of a disease may show important changes in the body and provide information
      about possible treatments. However, unlike repositories of blood and tissue samples,
      researchers do not have a repository of fecal specimens. Researchers are interested in
      determining whether standard collection procedures used for fecal occult blood testing can
      provide accurate information on micro-organisms in the intestine.

      Objectives:

      - To determine whether standard fecal occult blood testing procedures can provide accurate
      collections of fecal micro-organisms for research purposes.

      Eligibility:

      - Healthy volunteers at least 18 years of age.

      Design:

        -  At the clinical center, participants will be provided with written and illustrated
           instructions for the collection procedures and a self-administered risk questionnaire.
           The questionnaire will assess the challenges of collecting fecal specimens and will
           collect data on major dietary restrictions (e.g., vegan, vegetarian, food allergies),
           medication use and major illnesses, knowledge of and past experience with fecal occult
           blood testing, colonoscopy and colon cancer, and the fecal collection devices.

        -  Participants will be provided with a collection bag for the sample, 16 sample collection
           tubes, and a box with frozen gel packs.

        -  On the morning of collection, participants will collect the fecal sample in the bag and
           use the collection tubes to obtain material from different parts of the stool.

        -  The tubes will be sealed and placed in the box with the gel packs, and the participant
           will hand deliver the entire box to the clinical center.

        -  Characteristics of the bacteria in the material will be measured by laboratories at the
           University of Maryland.

        -  Statistical comparisons will determine how well the procedures worked.
    

Detailed description: 
      Commensal bacteria and other microbial organisms (the microbiota), particularly in the
      intestines, are centrally related to nutrition, metabolism, immunity, inflammation, and
      endocrine balance. As an initial step toward possible establishment of a biobank of feces
      that could be used for prospective studies of the relationship of microbiota to cancer and
      other conditions, we propose a study to evaluate whether fecal microbiota, as well as
      microbial enzyme expression and function, are reproducibly represented in feces that has been
      collected with a device that is widely used for fecal occult blood testing (FOBT-CHEK oc). To
      do so, this study will recruit a convenience sample of 50 volunteers from DCEG and others at
      NIH. From a single stool, each participant will provide 16 aliquots of feces, half collected
      with FOBT-CHEK oc and the rest with a larger Sarstedt device. A urine sample and a brief
      self-administered questionnaire on antibiotics and other medications, serious chronic
      diseases, and major cancer risk factors will also be obtained. The aliquots will be used for
      microbiome pyrosequencing, beta-glucuronidase and beta-glucosidase expression and enzymatic
      activity. Variance within and between collection devices, as well as between individuals,
      will be quantified. This study will provide insight and quantitative estimates that will be
      required for formal studies of the relationship of the fecal microbiome to cancer. Under an
      amendment, to examine the ability of selected antibiotics to stabilize fecal microbial
      populations when they have been stored at 3 or 7 days prior to freezing, 10 of the same
      volunteer participants will be asked to provide aliquots of a second stool specimen.
      Differences between immediate and delayed freezing with or without the antibiotics will be
      tested by analysis of variance. Under an amendment, up to 100 participants will be enrolled
      to examine reproducibility of the microbiota with a used commercial colorectal cancer
      screening device and the stability of the microbiota within individuals over four years,
      participants will be asked to collect specimens during 2014, exactly as was done during 2010.
      Assays and anlyses will be analogous to those performed previously.
    

Observational model: Ecologic or Community
Time perspective: Cross-Sectional
Keywords: Estrogens; Fecal Microbiome; Fecal Occult Blood