Trial Information

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

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(Registered Trademark)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(Registered Trademark)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.