Reproducibility of a Fecal Occult Blood Test Device for Gut Microbiota Analyses

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.