Patent ID: 8097417

Claim:
A non-invasive method for monitoring the effects of an agent for treating colorectal cancer, comprising: (1) collecting fecal samples from a first group of subjects, a second group of subjects, and a third group of subjects to provide a first group of fecal samples, a second group of fecal samples, and a third group of fecal samples, respectively, wherein the first group of subjects consists of a plurality of healthy subjects, the second group of subjects consists of a plurality of subjects at risk of developing colorectal cancer, and the third group of subjects consists of a plurality of subjects at risk of developing colorectal cancer and being treated with an anti-cancer agent; (2) isolating total microbial genomic DNA from the first group of fecal samples, the second group of fecal samples, and the third group of fecal samples to provide a first group of total microbial genomic DNA, a second group of total microbial genomic DNA, and a third group of total microbial genomic DNA, respectively; (3) comparing the first group of total microbial genomic DNA, the second group of total microbial genomic DNA, and the third group of total microbial genomic DNA using fingerprint spectrum analysis technique to provide a first group of fingerprints, a second group of fingerprints, and a third group of fingerprints, wherein the fingerprint spectrum analysis technique comprises amplifying the V3 regions of 16S rDNA gene to serve as a template to differentiate the compositional differences in the fecal flora of the first group of fecal samples, the second group of fecal samples, and the third group of fecal samples; (4) identifying key fingerprint bands correlated with the effect of the anti-cancer agent by analyzing the major band patterns of the first group of fingerprints, the second group of fingerprints, and the third group of fingerprints using partial least squares-discriminate analysis; (5) identifying key microorganisms associated with the key fingerprint bands; (6) designing microbial sequence-specific primers and probes based on the sequences of the key microorganisms; (7) determining the quantitative differences of the key microorganisms in the first group of fecal samples, the second group of fecal samples, and the third group of fecal samples using quantitative real-time PCR analysis using the microbial sequence-specific primers and probes to identify an indicator microorganism for monitoring the effect of the anti-cancer agent, wherein the indicator microorganism is the key microorganism that shows a quantitative difference between the second group of fecal samples and both the first group and the third group of fecal samples and no quantitative difference between the first group of fecal samples and the third group of fecal samples.