Poop Science: Stool Samples Could be Used for Early Colorectal Cancer Diagnosis

Scientists from Washington State University and John Hopkins Medical School have discovered the potential of fats in feces as a fast, non-invasive diagnostic tool for early detection of colorectal cancer.

Their findings, published in the Journal of Proteome Research, showed that the feces of a patient with colon cancer have some kind of "metabolic fingerprint" that matches the changes in colon tumor tissues.

"The feces was not exactly the same as the tissue samples, but it had a lot of similarities to the tissue," explained Herbert Hill, a professor at Washington State University and lead author of the study, in a press release. "We found the lipids and fatty acids were changing -- and there were also changes in the amino acids."

For the new diagnostic tool, the researchers used an ultrasensitive, high-speed technology called ion mobility-mass spectrometry or IMMS. By coupling IMMS with ultraperformance liquid chromatography, the researchers were able to measure hundreds of metabolites simultaneously, such as enzymes, fats, glucose and amino acids.

The researchers first identified metabolic products from normal colon tissues in both humans and mice. They then compared these normal profiles to that found in cancerous colon tissues from humans and research mice with polyps in their colons that mimic those in humans. The researchers found that colon cancer, both in humans and mice, caused significant changes in fat metabolism, especially for lipids and fatty acids.

Then, the researchers examined the feces of transgenic and control mice. Many of the molecular fingerprint caused by metabolic abnormalities found in the cancerous colon cells were also detected in the feces. Specifically, a certain type of lipids called lysophospholipids, which are important for the development of cancer cells.

 The researchers noted that a lot of study is needed to be done before their new method can be put into clinical practice. However, the new method shows tremendous promise as a noninvasive, more comprehensive early-warning detection method for colorectal cancer.