DNA from fecal immunochemical test can replace stool for detection of colonic lesions using a microbiota-based model.

Nielson T Baxter,Mack T Ruffin,Mary A M Rogers,Charles C Koumpouras,Patrick D Schloss

doi:10.1186/s40168-016-0205-y

Nielson T Baxter, Mack T Ruffin + Show 3 more

Open Access

https://doi.org/10.1186/s40168-016-0205-y

Copy DOI

Abstract

BackgroundThere is a significant demand for colorectal cancer (CRC) screening methods that are noninvasive, inexpensive, and capable of accurately detecting early stage tumors. It has been shown that models based on the gut microbiota can complement the fecal occult blood test and fecal immunochemical test (FIT). However, a barrier to microbiota-based screening is the need to collect and store a patient’s stool sample.ResultsUsing stool samples collected from 404 patients, we tested whether the residual buffer containing resuspended feces in FIT cartridges could be used in place of intact stool samples. We found that the bacterial DNA isolated from FIT cartridges largely recapitulated the community structure and membership of patients’ stool microbiota and that the abundance of bacteria associated with CRC were conserved. We also found that models for detecting CRC that were generated using bacterial abundances from FIT cartridges were equally predictive as models generated using bacterial abundances from stool.ConclusionsThese findings demonstrate the potential for using residual buffer from FIT cartridges in place of stool for microbiota-based screening for CRC. This may reduce the need to collect and process separate stool samples and may facilitate combining FIT and microbiota-based biomarkers into a single test. Additionally, FIT cartridges could constitute a novel data source for studying the role of the microbiome in cancer and other diseases.

Highlights

There is a significant demand for colorectal cancer (CRC) screening methods that are noninvasive, inexpensive, and capable of accurately detecting early stage tumors
We compared the number of Operational taxonomic unit (OTU) shared within fecal immunochemical test (FIT)/ stool pairs from the same patient to the number of OTUs shared between patients (Fig. 1a)
FIT cartridges and stool from the same patient had significantly more bacterial populations in common than those taken from different patients (p < 0.001, two-sample Kolmogorov-Smirnov test), indicating that community membership was conserved within patients across stool and FIT cartridges

Summary

Introduction

There is a significant demand for colorectal cancer (CRC) screening methods that are noninvasive, inexpensive, and capable of accurately detecting early stage tumors. Some do not consider these invasive tests as a primary screening option, but they are in the USA [5] Noninvasive tests, such as the guaiac fecal occult blood test (gFOBT), fecal immunochemical test (FIT), and the Several studies have demonstrated the potential for the gut microbiota to be used to detect CRC [8,9,10,11]. We hypothesized that the small amount of fecal material contained in FIT sampling cartridges was sufficient to Baxter et al Microbiome (2016) 4:59 perform both hemoglobin quantification and microbiota characterization To test this hypothesis, we isolated bacterial DNA from the residual buffer of OC-Auto® FIT cartridges (Polymedco Inc.) that had already been used for quantifying fecal hemoglobin concentrations. We compared the bacterial composition of the FIT cartridge to that of DNA isolated directly from a patient’s stool sample and assessed the ability of FIT cartridgederived DNA to be used for microbiota-based CRC screening

Methods

Results

Discussion

Conclusion